Who invented stainless steel and when?

Stainless steel: who invented it and when?

A hundred years ago, the world heard about a wonderful material that is extremely widely used in various areas of our lives - stainless steel.

Stainless steel: who invented it and when?

1915 - the world learned about stainless steel

The public often learns about technological innovations from the media, but such reports are usually not based on diplomatic sources. On January 31, 1915, this rule was broken. The New York Times published a short article entitled A Non-Rusting Steel.

The newspaper report said that a company in the British city of Sheffield had launched a new type of steel "that does not corrode, tarnish or stain." The manufacturer claimed that it is extremely suitable for making cutlery, since products made from it are easy to wash and do not lose their shine when in contact with even the most acidic foods.

The American consul in Sheffield, John Savage, was named as the source of the information. This is how, without much fuss and with considerable delay, the world learned about the invention of stainless steel.

Ancestors of stainless steel

In fact, such steel was produced in Europe and the USA even before the Sheffield metallurgists. Ordinary steel, an alloy of iron and carbon, is easily coated with a film of iron oxide - that is, it rusts.

By the way, this very circumstance was one of the reasons for the brilliant commercial success of the American entrepreneur King Kemp Gillette, who invented the safety razor. In 1903, his company sold only 51 blades, in 1904 - almost 91,000, and by 1915, total sales exceeded 70 million.

Gillette blades, which were made from unalloyed steel from Bessemer converters, quickly rusted and became dull and therefore required frequent replacement.

It is curious that the recipe for combating this disease of the main metal of the then industry was found long ago. In 1821, French geologist and mining engineer Pierre Berthier noticed that iron-chromium alloys had good acid resistance, and proposed making kitchen and table knives, forks and spoons from them. However, this idea remained a wish for a long time, since the first alloys of iron and chromium were very brittle.

It was only at the beginning of the 20th century that iron alloy formulations were invented that could claim the title of stainless steel. Among their authors was one of the pioneers of the American automobile industry, Elwood Haynes, who intended to use his alloy to make metal-cutting tools.

In 1912, he applied for a corresponding patent, which was granted only seven years later after lengthy disputes with the US Patent Office.

Chance find

But the official parent of the well-known stainless steel was a man who did not look for it at all and created it only thanks to a happy accident. This lot fell to the self-taught English metallurgist Harry Brearley, who in 1908 headed a small laboratory established by two Sheffield steel companies.

In 1913, he conducted research on steel alloys that were supposed to be used to make gun barrels. Scientific metallurgy was then in its infancy, so Brearley acted by trial and error, testing alloys with different additives for strength and heat resistance.

He simply put the unsuccessful pieces in the corner, and they quietly rusted there. He once noticed that a casting taken out of an electric furnace a month ago did not look rusty at all, but shined like new. This alloy contained 85.3% iron, 0.2% silicon, 0.44% manganese, 0.24% carbon and 12.8% chromium.

It was he who became the world's first example of that steel, which was later reported by the New York Times. It was smelted in August 1913.

Blades for Gillette machines were made of hard carbon steel. They were not very durable, as they rusted easily from constant exposure to moisture.

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Failure and success[/h2]

Brearley became interested in the unusual casting and soon discovered that it resisted nitric acid well. Although the new alloy was not successful as a weapon steel, Brearley realized that this material would have many other uses.

Sheffield has been famous for its metal products such as knives and cutlery since the 16th century, so Brearley decided to try out his alloy for this purpose. However, two local manufacturers to whom he sent the castings were skeptical of his proposal.

They found that knives made from the new steel required more labor to manufacture and harden. Metallurgical companies, including the one for which Brearley worked, were also not enthusiastic.

It is clear that both cutlers and metal manufacturers feared that stainless steel products would be so durable that the market would quickly become saturated and demand for them would fall. Therefore, until the summer of 1914, all Brierley’s attempts to convince industrialists of the promise of the new alloy did not lead to anything worthwhile.

But then he got lucky. In the middle of summer, fate brought him into contact with his school friend Ernest Stewart. Stewart, an employee of the cutlery company RF Mosley & Co, at first did not believe in the reality of the existence of steel, which is not subject to rust, but agreed to make several cheese knives from it as an experiment.

The products turned out to be excellent, but Stuart considered this venture a failure, since his tools quickly became dull when making these knives. But in the end, Stewart and Brearley finally found a heating mode at which the steel could be processed and did not become brittle after cooling.

In September, Stewart made a small batch of kitchen knives, which he distributed to friends for testing with one condition: he asked to return them if stains or rust appeared on the blades of the knives. But not a single knife ever returned to his workshop, and soon Sheffield manufacturers recognized the new steel.

Cutters and knives

In August 1915, Brearley received a patent for his invention in Canada, in September 1916 - in the USA, and then in several European countries. Strictly speaking, he did not even patent the alloy itself, but only the knives, forks, spoons and other cutlery made from it.

Haynes challenged Brearley's American patent on the grounds of priority, but the parties eventually reached an agreement. This made possible the establishment in Pittsburgh of a joint Anglo-American corporation, The American Stainless Steel Company.

But that's a completely different story.

It is worth noting that Haynes stainless steel contained much more carbon than Brearley steel, and therefore had a different crystalline structure. This is understandable: carbon provides hardness during hardening, and Haynes sought to create an alloy for the manufacture of machine cutters and milling cutters. Nowadays, Haynes-type steels are called martensitic, and steels that historically go back to the Brearley alloy are called ferritic (there are other types of stainless steels).

Natural taste

Stewart not only opened the way to the use of new steel, but also found for it the now generally accepted English-language name stainless steel, “steel without stains.”

According to the standard explanation, it occurred to him when he dipped a polished steel plate in vinegar and, looking at the result, said in surprise: “This steel stains less,” that is, “There are few stains on this steel.”

Brearley called his brainchild a little differently - rustless steel, which corresponds to the Russian term “stainless steel”. By the way, the title of the article in the New York Times announced the appearance of stainless steel (not low-rust!) steel.

Her secret is simple. With a sufficient concentration of chromium (at least 10.5% and up to 26% for particularly aggressive environments), a solid transparent film of chromium oxide Cr2O3 is formed on the surface of stainless steel products, firmly adhered to the metal.

It forms a protective layer invisible to the eye, which does not dissolve in water and prevents the oxidation of iron, and therefore does not allow it to rust. This film has another valuable quality - it self-heals in damaged areas, so it is not afraid of scratches.

Stainless steel cutlery has gained immense popularity also because it allows us to get rid of the specific taste characteristic of inexpensive metal utensils.

The chromium oxide layer allows you to enjoy the natural taste of food, since it prevents direct contact of the taste buds of the tongue with the metal. In general, stainless steel, which the modern industry produces in many varieties, is truly a remarkable accidental invention.

[h2]
Types of stainless steel[/h2]

Stainless steels differ in properties, composition and purpose, but in general they can be divided into several main groups according to their crystal structure: ferritic, austenitic, martensitic and two-phase (ferritic-austenitic).

Ferritic stainless steels are chromium (10−30% chromium) and low-carbon (less than 0.1%) steels. They are quite strong, ductile, relatively easy to process and at the same time cheap, but cannot be heat treated (hardening).

Martensitic stainless steels are chromium (10−17% chromium) steels containing up to 1% carbon. They lend themselves well to heat treatment (hardening and tempering), which gives products made from such steels high hardness (knives, bearings, and cutting tools are made from them). Martensitic steels are more difficult to process and, due to their lower chromium content, are less resistant to corrosion than ferritic steels.

Austenitic stainless steels - chromium-nickel. They contain 16−26% chromium and 6−12% nickel, as well as carbon and molybdenum. They are superior to ferritic and martensitic steels in corrosion resistance and are non-magnetic. High strength is obtained by cold-working (hardening); during heat treatment (hardening), their hardness decreases.

Dual-phase steels combine various properties of ferritic and austenitic steels.

[h2]
Heavenly Iron[/h2]

Quite often you can come across the statement that meteorite iron does not rust. In fact, this is pure myth. Iron-nickel meteorites contain about 10% nickel, but do not contain chromium, and therefore do not have corrosion resistance. You can verify this by visiting the mineralogical section of a natural history museum.

Taking a closer look at samples of iron-nickel meteorites (say, the Sikhote-Alin meteorite, which is often found in such exhibitions), you can see numerous traces of rust. But a sample of an iron-nickel meteorite purchased at a mineralogical souvenir store most likely will not really rust. The reason is “pre-sale preparation”, which consists of coating the sample with a thick protective lubricant.

It is necessary to wash off this grease with a solvent - and then the moisture and oxygen of the atmosphere will take revenge.

Indian miracle

Blades for Gillette machines were made of hard carbon steel. They were not very durable, as they rusted easily from constant exposure to moisture. More

The Iron (Kutubov) Column is one of the main attractions of Delhi. Erected in 415, it has suffered almost no corrosion for 1,600 years - only small spots of rust are visible on the surface, while ordinary steel products of a similar size during this time are almost completely oxidized and crumble into dust.

Many hypotheses have been put forward in attempts to explain this phenomenon: the use of very pure or meteorite iron, natural nitriding of the surface, bluing, constant oil treatment, and even natural radioactive irradiation, which turned the top layer into amorphous iron. There were attempts to explain the preservation of the column by external factors - in particular, a very dry climate.

Analyzes showed that the column consists of 99.7% iron and does not contain chromium, that is, it is not stainless in the modern sense of the word.

The main impurity in the column material is phosphorus, and this, according to scientists, is the main reason for corrosion resistance.

A layer of FePO4·H3PO4·4H2O phosphates less than 0.1 mm thick is formed on the surface, and, unlike rust, which crumbles and does not prevent further oxidation, this layer forms a durable protective film that prevents rusting of iron.

Source: https://vilingstore.net/article/190632/nerzhaveyushhaya-stal-kto-i-kogda-ee-izobrel/

When did stainless steel appear?

It is impossible to imagine modern life without anti-corrosion steel. The development of such an alloy has made it possible to make a qualitative breakthrough not only in metallurgy, but also in many other areas. Stainless steels differ from classical ones in that in addition to iron and carbon, they also contain chromium. It is the addition of chromium that gives the alloy anti-corrosion properties.

Stainless steel products are very diverse. You can find a wide selection of products from any manufacturer. For example, high-quality products, as confirmed by numerous reviews, can be ordered in the BSM - Metal online store.

Physical properties

Stainless steel has gained high popularity not only due to its anti-corrosion properties, but also due to its variety of physical properties. Modern corrosion-resistant steels are produced by adding various impurities to the steel.

The physical properties of the finished steel depend on the amount and type of impurity. It should be noted that some grades of stainless steel are susceptible to corrosion after a long period of use. This is due to the composition, that is, the addition of this or that metal. Such an alloy has other advantages that eliminate susceptibility to oxidation.

It is necessary to highlight the main physical properties of stainless steel, which qualitatively distinguish it from a number of other metals. These properties include:

1. High strength. Products made from stainless steel are characterized by increased strength in comparison with analogues. Due to its resistance to physical stress, the products are not damaged and do not lose their original shape. High-quality steel remains reliable for more than ten years.
2. Resistance to aggressive external environment. Such steel is practically not subject to changes due to environmental conditions. This allows you to maintain the performance properties of the product for a long time.
3. Heat resistance. Stainless steel products are resistant to high temperatures, even when exposed to open fire. Also without changing shape, size and properties under significant temperature changes.
4. Environmental friendliness. Anti-corrosion properties prevent the oxidation process. In addition, the material does not contain harmful components, therefore it is widely used in the food industry.
5. Anti-corrosion properties. The main property that such steel has is that it prevents rust. Moreover, the alloy does not corrode even after exposure to acids or alkalis.
6. Appearance. The appearance of stainless steel products is qualitatively different from items made of other materials. Steel has a clean, shiny appearance that does not change after a long period of use.
7. Compliance. Such an alloy is easy to process, and making an object of the desired shape from it is not difficult.

The choice of stainless steel with certain physical properties depends on the purpose of its use. Today, a variety of components for the production of stainless steel allows you to create a material with the necessary characteristics.

Chemical composition

The chemical composition of stainless steel depends on the type and grade of the alloy. The main features that characterize stainless steel are the presence of at least 10.5% chromium and low carbon content. Carbon is very important in steel making as it gives the required strength. The percentage component of which in the anti-corrosion alloy should not exceed 1.2%.

Stainless steel may also contain Titanium, Phosphorus, Molybdenum, Sulfur, Nickel and Niobium. Depending on the chemical composition, stainless steel is divided into several types.

The most widely used is stainless steel of group A2. Group A2 contains 10% nickel, 18% chromium and 0.05% carbon. Most of it is occupied by the base, namely iron with accompanying components.

The composition of steels in this group includes 0.05% carbon, 2% molybdenum, 12% nickel and 17% chromium. Due to the presence of molybdenum in the composition, the alloy is resistant to acid, so the name “acid-resistant” is often applied to it.

Anti-corrosion steels of group A, due to their chemical composition, are easy to weld. That is why this type is widely used in industry. From such steel it is possible to produce parts of almost any shape, with a strong connection of the component parts.

Particular attention in production is paid to steel for the food industry. In this case, corrosion-resistant steel should not contain foreign components that can negatively affect the taste of products, as well as impurities hazardous to human health.

The resistance of steel to corrosion depends on the amount of chromium. The larger its component, the more stable the alloy. Classic stainless steel used under normal conditions contains no more than 13% chromium. To withstand an aggressive environment, the proportion of chromium must exceed 17%. This corrosion-resistant alloy is suitable for use in acidic environments.

Read also: How to drill hardened metal at home

Highly resistant alloys retain their properties even in nitric acid of 50% saturation. For resistance against stronger acids, the percentage of nickel in the composition is increased and other components are added in small quantities.

Classification of stainless steels

The classification of stainless steels varies among countries, but has common principles. Stainless steel marking is carried out depending on the chemical composition, properties and internal structure of the finished material. Based on this, steel is divided into the following types:

1. Ferritic. This group of steels is characterized by a high chromium content, usually more than 20%. Therefore, this type is sometimes called chromium. This chemical composition contributes to high resistance to aggressive external environments. Alloys of this group have magnetic properties. Ferritic steels are relatively cheap and are widely used in industry, second only to austenitic steels.
2. Austenitic. A group of anti-corrosion alloys that are characterized by a high content of chromium and nickel. Due to this, they are distinguished by increased strength and flexibility in comparison with analogues. Also easy to weld and resistant to corrosion. Most widely used in industry. They belong to non-magnetic metals.
3. Martensitic. A special type of stainless alloy. It is characterized by increased strength and wear resistance. They are not exposed to high temperatures, and at the same time contain a minimal part of harmful components that do not emit vapors during intense heating. This group includes heat-resistant, corrosion-resistant steel.
4. Combined. A special type of steel that combines the properties of the above groups. Such innovative steels are developed individually depending on the properties required by the customer. Today, austenitic-ferritic and austenitic-martensitic steels are distinguished.

Stainless steel parts

In turn, grades of stainless steel of the austenitic group are divided into 4 types:

1. A1 is steel that contains a significant amount of sulfur, which is why it is more susceptible to corrosion than others.
2. A2 is the most widely used grade. Easily weldable without loss of physical properties. Frost-resistant, but susceptible to corrosion in an aggressive acidic environment.
3. A3 is a derivative of A2, but with the addition of stabilizing components. It is characterized by increased resistance to high temperatures and acidic environments.
4. A4 – alloy with the addition of molybdenum (up to 3%). Characterized by resistance to acidic environments. Widely used in shipbuilding.
5. A5 – similar to the A4 brand. It differs only in the ratio of stabilizing components. Manufactured for increased resistance to high temperatures.

Types of stainless steel are not limited to the above types. Since even the slightest changes in the percentage of components can significantly affect the properties of steel.

Scope of application of stainless steels

Since their development, corrosion-resistant steels have been used only in high-tech production in such areas as aircraft manufacturing, nuclear energy, petrochemical production and mechanical engineering. Today, stainless steels are widely used in various areas of our lives.

Stainless steel car detail

Let us highlight the main areas of use of stainless alloys:

1. Mechanical engineering. Stainless steel is widely used for the production of cars, industrial machines and various units. Ferritic and austenitic types are commonly used.
2. Chemical industry. The chemical industry is accompanied by the use of aggressive substances, the maintenance of which requires special equipment. Austenitic alloys are used for its production. Production tanks, pipes and vessels are not exposed to chemicals and do not lose their performance properties.
3. Energy. In the electrical power industry, only high-strength materials are used, since the strength and reliability of working units are of particular importance.
4. Pulp and paper industry. Almost all equipment in this area is made of high-quality stainless steel.
5. Food industry. There are increased requirements for the production, storage and transportation of food products. Therefore, in the manufacture of equipment, you can only use glass, several types of plastic and stainless steel. This ensures an increased level of hygiene.

Read also: Iron for a toroidal transformer

In the food industry, an alloy containing a small number of components is usually used, since the equipment is not exposed to ultra-high temperatures and aggressive substances. Frost-resistant materials are used for refrigeration units.

1. Aerospace sector. Special types of stainless steel began to be used to build airplanes, rockets and spaceships.
2. Construction. Stainless steel is widely used in construction and design. Such sheets are scratch-resistant and do not leave hand marks.

Corrosion-resistant steels are also used in many fields, due to the variety of types and properties.

Source: https://morflot.su/kogda-pojavilas-nerzhavejushhaja-stal/

Who invented stainless steel and when?

Stainless steel is widely used in many areas of daily life and was first introduced to the world in 1915. Then a note was published in the New York Times, which said that steel had been invented that retains color and does not stain or rust. The same note said that this material is best used to create cutlery, because they will not oxidize when in contact with food and various detergents.

Predecessors of stainless steel

Stainless steel was used all over the world even before the above note. The big disadvantage of ordinary steel is that it rusts relatively quickly. In 1821, Pierre Berthier noticed that if iron is alloyed not with carbon, but with chromium, then it has greater resistance to acids. But only in the twentieth century did this alloy become widely used, because the first samples were quite fragile.

In 1912, Elwood Haynes submitted a patent for the invention of stainless steel, from which he wanted to produce metal-cutting tools.

Who invented steel

The official inventor is the man who did not need fame - Harry Brearley, who worked as a metallurgist without education. Since 1908, he began working in the laboratory, and in 1913 he carried out tests on steel alloys. Working “blindly,” he tried and made mistakes, and simply put the unsuccessful samples in a corner where they rusted.

One of the alloys did not rust after a month, which attracted the attention of the scientist. It was this steel that was mentioned in the newspaper later. After his discovery, Brearley decided that this alloy could be useful in many areas of life, so he began to contact various factories and even small workshops.

The city of Sheffield, where he was located, was famous for its cutlery and knives, so he decided to first conquer this niche. Unfortunately, no matter where he turned, no one supported his enthusiasm. The owners of workshops and factories thought that such products would require a lot of labor.

And the products will turn out to be so durable that soon the market will be filled and will no longer require new inventions.

Until the summer of 1914, Brearley was unable to find an accomplice to make knives or cutlery until he met Ernest Stewart. At that time, Ernest was working with RF Mosley & Co and agreed to accept Brearley steel for testing.

Together, until September, they found the ideal temperature and method of processing this steel, and produced the first batch of knives, which they distributed to their relatives and friends. The use of knives had one condition - if the tool becomes covered with rust, it must be returned.

None of the knives ever returned to the workshop, and after that other manufacturers began to accept stainless steel.

During 1915-1916, Brearley received patents in various countries - Canada, America, European countries. Haynes already had a patent in America, so he protested what Brearley had invented. Eventually, they were able to come to an agreement, which made it possible for England and America to jointly open a company called The American Stainless Steel Company.

The article was prepared by UTMK.

Source: https://worldnewsage.com/ru/zhizn/kto_i_kogda_izobrel_nerzhaveyushchuyu_stal_1490603101

Discovery of steel

Surprisingly, steel is not considered an invention of the New Age; the material was mentioned in ancient treatises.

Steel has always been considered a sought-after product. The history of its discovery can be divided into three periods:

• ancient times , when cheese forges appeared;
• the Middle Ages , when the remaking process was discovered;
• second half of the 19th century . This period is associated with the beginning of cast steel production.

Ancient times

The first mentions of steel production were known already 1000 BC. Chinese metallurgists in the 2nd century. BC. they made it from cast iron. This method is called "one hundred cleanses." It consisted of repeated intensive blowing of air onto molten cast iron while moving it. This led to a decrease in the proportion of carbon in the metal and an approach to the properties of steel.

The discovery is mentioned in the treatise “Hainanji” (122 BC). It should be noted that literally until the 19th century, steel was almost not used, because its production was very labor-intensive and expensive.

When the demand for cheap steel increased sharply and scientists had the idea to find an answer to the question “how to obtain metal with the properties of iron in liquid form so that it can be used for casting?” - they took this matter seriously. It took many decades to solve this problem with the participation of many physicists.

Until the end of the 18th century, the process of producing cast iron into soft malleable iron was carried out exclusively in forges . But this method of converting cast iron was very labor-intensive and complex, requiring a lot of costs (it took up to 4 kg of coal to restore 1 kg of iron). The question arose about the need to find a new method of processing cast iron.

Middle Ages

From 1742, Benjamin Huntsman began to smelt steel not in an open furnace with charcoal, but in a heated crucible . The process of producing steel is called puddling . The main difference between a puddling furnace and a furnace was that it was possible to use any combustible fuel, not just coal. For example, raw coal could be used.

Also, the puddling furnace did not require forced injection, and air access and the necessary draft were achieved using a high pipe. The discovery of a new method made it possible to obtain cheaper steel, and Hutsman furnaces began to be used throughout the world.

But not everything went so smoothly. Pudding furnaces had a significant drawback : in order to reduce iron evenly, it was necessary to periodically open the furnace and stir the cast iron, and this was not an easy task.

In addition, the furnace was small in size, therefore, not much material was processed at a time.

Second half of the 19th century and modern times

By the middle of the 19th century, puddling furnaces no longer met the needs of industry. Many scientists began to work on the issue of replacing steel production technology. The first to solve the problem was a scientist from the English city of Sheffield, Harry Brearley .

He is called the discoverer of “stainless steel” and the man who replaced the puddling furnace with a blast furnace (compressed air was blown through the mass of phosphorus-poor cast iron, which promoted oxidation processes). In 1913, he patented the very first version of martensitic steel. It was this that became the predecessor of modern steel under the AISI 420 brand. In 1878.

Sidney Gilchrist Thomas succeeded in inventing the "Thomas process" to remove phosphorus impurities from iron ore during the smelting process. Despite this, the first scientist to document all the positive chemical properties of stainless steel is considered to be the French scientist and inventor Leon Gillette .

In 1912, Eduard Maurer and Benno Strauss of the German company Krupp Iron Works patented the first austenitic steel, which contained 7% nickel and 21% chromium. Ten years later, in 1924, Hartfield (Brealy's successor) patented stainless steel under the brand 18-8 (18% chromium and 8% nickel). At this time, oxygen converters and electric furnaces for steel smelting appeared.

In 1952, the world's first steel plant based on the LD process, which consisted of removing impurities from cast iron in a converter by blowing with technical oxygen, opened in Austria.

In less than a century, stainless steel has become the most sought-after material in industrial production. Today there are about 100 types of stainless steel with a chromium percentage greater than ten.

Airplane and train bodies, small household appliances and instruments, medical equipment, etc. are made from this material.

Source: http://www.phisiki.com/2012-02-28-10-51-54/55-otkritie-stali

The whole history of steel - Technology - 2020

Jonathan Shifman

The history of steel begins long before bridges, I-beams and skyscrapers. It starts in the stars.

Billions of years before humans walked the Earth—before the Earth even existed—blazing stars fused atoms into iron and carbon. Over countless cosmic explosions and rebirths, these materials found their way into asteroids and other planetary bodies, which crashed into each other as the cosmic pot stirred. Eventually, some of these rocks and metals formed the Earth, where it would determine the fate of one particular species of walking ape.

On a day lost to history, some random people discovered a shiny meteorite, mostly iron and nickel, that entered the atmosphere and crashed into the ground. Thus began an obsession that swept the species.

Over thousands of years, our ancestors processed the material, discovering better ways to extract iron from the Earth itself and ultimately smelt it into steel.

We will fight for it, create and destroy nations with it, develop global economies with it, and use it to create the greatest inventions and structures the world has ever known.

Metal from heaven

King Tut carried an iron dagger, a treasured item in the ancient world, worthy of few more than a pharaoh. When British archaeologist Howard Carter found Tutankhamun's tomb almost a century ago and saw the object, it was clear that the dagger was special. At the time, archaeologists did not know that the blade came from outer space.

Polytechnic University of Milan

Iron that comes from meteorites has a higher nickel content than iron dug out of the ground and smelted by humans. In the years since Carter's big discovery, researchers have discovered that not only King Tut's dagger, but virtually all iron objects dating back to the Bronze Age were made from iron that fell from the sky.

To our ancestors, this exotic alloy must have seemed sent by entities beyond our understanding. The ancient Egyptians called it business-n-pt. In Sumer it was known as an-bar. Both translate as "metal from heaven." The iron-nickel alloy was flexible and easily hammered into shape without breaking. But there was an extremely limited quantity, delivered to Earth only by random extraterrestrial routes, which made this metal of the gods more valuable than precious stones or gold.

Thousands of years passed before people began to look at their feet. Around 2500 BC Tribesmen in the Middle East have discovered another source of dark metallic material hidden underground. It looked just like the metal from heaven - and it did, but something was different.

Iron was mixed with rocks and minerals mixed into ore. Extracting iron ore wasn't like picking up random pieces of gold or silver.

Removing iron from the underground realms was a temptation from the spirit world, so early miners performed rituals to appease higher powers before digging for ore, according to a 1956 book. Forge and Crucible.

But getting the iron ore off the Earth was only half the battle. It took the ancient world another 700 years to figure out how to separate the precious metal from its ore. Only then will the Bronze Age truly end and the Iron Age begin.

A long way to the first steel

To know steel, we must first understand iron, because metals are almost the same thing. Steel contains iron in a concentration of 98 to 99 percent or more. The rest is carbon - a small additive that significantly affects the properties of the metal. In the centuries and millennia before the breakthroughs that built skyscrapers, civilizations were fine-tuned and refined by smelting to bring iron ever closer to steel.

Around 1800 BC a people on the Black Sea called the Chalibs wanted to make a metal stronger than bronze—something that could be used to make unrivaled weapons. They placed iron ores into hearths, hammered them and fired them to soften them. After repeating this process several times, the Chalibs pulled out strong iron weapons from the forge.

Michael Stillwell

What the Chalibs made is called wrought iron, one of several major predecessors to modern steel. They soon joined the warlike Hittites, creating one of the most powerful armies in ancient history. No national weapon corresponded to the Hittite sword or chariot.

Steele's other little brother, so to speak, is cast iron, which was first made in ancient China. Beginning around 500 BC, Chinese metalworkers built furnaces seven feet high to burn large quantities of iron and wood. The material was smelted into a liquid and poured into carved molds, taking the shape of culinary tools and statues.

However, neither wrought iron nor cast iron was an ideal mixture. The wrought iron in Chalibah contained only 0.8% carbon, so it did not have the tensile strength of steel.

Chinese cast iron, with a carbon content of 2 to 4 percent, was more brittle than steel. Black Sea blacksmiths eventually began inserting iron rods into piles of hot white coal, which created wrought iron coated with steel.

But the South Asian community had a better idea. India will produce the first real steel.

Source: https://ru.sciencetis.com/83729-history-of-steel-29

Food grade stainless steel: history and time of appearance, description and properties, popular brands and scope of application

It's hard to believe, but stainless steel was invented only in the second half of the 19th century. For thousands of years before this, humanity could not cope with the phenomenon of corrosion.

The discovery of the ability of iron and chromium alloys to resist acid attack did not immediately change the industry. The first stainless steel products were cutlery, which was produced as competitors to traditional silverware.

It took many years for the new material to begin to be used not only for the manufacture of forks and knives.

As already mentioned, stainless steel was first used in the kitchen and dining rooms . Since then, it has established itself as a universal material for almost all areas related to food processing and storage. But of the more than 200 grades of stainless steel, not every one is called “food grade steel.”

The fact is that the term “food” itself is not a standard or brand, but only reflects a possible method of using the material. In the wide range of existing stainless steels, each of them has a unique set of qualities such as corrosion resistance, mechanical characteristics, susceptibility to processing, weldability, price, and heat resistance.

From a hygienic point of view, the following properties are important for materials in contact with products:

1. Non-toxic;
2. Chemical neutrality;
3. Corrosion resistance;
4. Smooth surface;
5. Lack of pores and absorbency;
6. High strength;
7. Easy to clean.

In addition, these properties of the material should not be violated after its processing into a product and during operation. Almost all existing stainless steels have no effect on food and drinking water upon contact. But the use of a particular brand is limited by such indicators as temperature, duration of interaction, and type of products. And of course, the cost of the material itself and its processing.

Steel grades and scope of application

Below is a list of some well-known brands of food grade stainless steel.

AISI 304

AISI 304 (12Х18Н10) is the alloy most used for contacts with products. Classic “food grade stainless steel”. AISI 304 steel grade contains about 0.05% carbon, 18% chromium and 8% nickel. It has excellent corrosion resistance to alkalis, atmospheric humidity and natural water, and is insensitive to weak organic and many inorganic acids. It is immune to sterilizing solutions and is heat-resistant.

Due to its ductility and good weldability, it has received the widest range of applications. All these qualities at a relatively low price make AISI 304 the best choice for designers and designers. The material also has significant disadvantages: it is not recommended for use in environments with high concentrations of chlorides, and tends to fade during use.

Scope of application:

1. Kitchen utensils and dishes;
2. Kitchen sinks and countertops;
3. Milk containers;
4. Beer tanks and barrels;
5. Catering equipment;
6. Machines and mechanisms for food production.

AISI 316

After stainless steel grade 304, grade AISI 316 (03Х17Н14М2) is perhaps the most common. Both are austenitic, non-magnetic and thermally non-hardening.

The main difference between 316 and 304 is the addition of molybdenum up to 2%. The latter increases the resistance of the chromium-nickel alloy, allowing it to withstand exposure to many solvents and industrial substances, in particular sulfur dioxide.

And most importantly, molybdenum is an inhibitor for pitting corrosion caused by chlorides.

Chloride solutions react with chromium and form compounds with it, leaving iron defenseless against oxidizing agents. As a result, pits appear on the surface of the stainless steel.

The likelihood of such pitting increases at high temperatures, high chloride concentrations and low pH. If the above factors coincide correctly, a vessel made of AISI 304 material can be damaged within a few hours.

Thanks to molybdenum, AISI 316 is significantly more resistant to aggressive environments in general and to pitting corrosion in particular.

Areas of use:

1. Containers with brines and sea water;
2. Wine storage equipment;
3. Containers for storing salty food;
4. Elements in the production of jams and pectin;
5. Equipment for the production of fruit juices.

AISI 430

AISI 430 (08X17) is another well-known “food grade stainless steel”. Refers to magnetic steels with low carbon content. It has good corrosion resistance in moderately aggressive environments and is difficult to oxidize at elevated temperatures.

Steel is very strong, can be processed by various methods of deformation, but has limited weldability, therefore it is not used in welded products for dynamic or shock-loaded structures.

Being a ferritic material, AISI 430 is susceptible to brittle fracture at sub-zero temperatures and is therefore not suitable for cryogenic conditions.

Since the alloy does not contain nickel and molybdenum, its cost is lower than that of the 300 series. AISI 430 is a simple anti-corrosion and heat-resistant steel grade that is used in areas where mildly aggressive conditions are encountered and resistance to them is required at moderate temperature increases:

1. Kitchenware and utensils;
2. Sinks and tables;
3. Parts of machines for winemaking;
4. Technological equipment for food production.

The three brands of food grade stainless steel described, in addition to versatility, have another important quality - low price , which is why they have gained their popularity. More than half of the world's total assortment is made up of steels 304, 316 and 430. In addition to them, there is a great variety of alloys with unique properties that can satisfy the most complex requirements of designers.

Areas of application of food grade stainless steel

Source: https://tokar.guru/metally/svoystva-i-sfery-primeneniya-pischevoy-nerzhaveyuschey-stali.html

Nickel-plated steel or stainless steel, which is better?

Steel, which has anti-corrosion properties, is actively used in many fields of activity; It has gained such high popularity because it has qualities that are unattainable for many other metal alloys.

The first grades of stainless steel appeared in 1913, when Harry Brearley invented an alloy with exceptional resistance to the formation and development of corrosion.

It was from this moment, which became a major milestone in the development of metallurgical and many other industries around the world, that the history of stainless steel begins, actively and successfully used by man for more than 100 years.

Finished stainless steel rolls

What do we know about stainless steel?

Corrosion-resistant steel or stainless steel is an alloy consisting of iron and carbon, additionally enriched with special elements that give it high resistance to negative environmental factors. The main one of these elements is chromium. Stainless steel contains at least 10.5% of it. Chromium, in addition to anti-corrosion properties, gives such alloys a number of positive characteristics:

• good processability by cold forming;
• exceptional strength;
• ability to obtain reliable connections by welding;
• possibility of long-term operation without loss of its characteristics;
• attractive appearance.

Chromium, contained in stainless steel in sufficiently large quantities, promotes the formation of a surface oxide film. It is this that protects the metal from corrosion.

Stainless steel sheet

Various grades (types) of stainless steel, and more than 250 of them have been created to date, contain in their chemical composition both chromium and a number of other alloying additives, the most common of which are nickel, titanium, molybdenum, niobium and cobalt. Naturally, steels with different proportions of alloying elements in their composition have different characteristics and areas of application.

As with any other type of alloy, carbon is an essential element in stainless steel. It is this element that gives the resulting metal alloy hardness and strength.

Today, it is impossible to imagine almost any industry without the use of stainless steel.

Grades of this alloy, all of which are distinguished by the ability to successfully operate even in the most aggressive environments, are used for the production of cutlery and medical instruments, containers for food liquids and products, pipes for transporting aggressive media, household appliances, and much more.

Stainless steel rods

Types and classification of stainless steel

Grades (types) of stainless steel are divided into several categories. Each of them is characterized by a certain chemical composition and internal structure of the material. Each of these categories of steel is distinguished by certain technical and operational characteristics, which determine the areas of their use. In modern industry, corrosion-resistant steels of the following categories are used.

Chromium steels with ferritic internal structure

Such alloys, which contain a fairly large amount of chromium (about 20%), are mainly used in heavy industry and for the production of elements of heating systems.

They are distinguished not only by exceptional corrosion resistance, but also by good magnetization ability.

In terms of demand, these steels are comparable to alloys with an austenitic structure, but at the same time they are much cheaper.

Stainless steel grades with austenitic internal structure

Such alloys, which contain up to 33% chromium and nickel, are the most used types of stainless steels worldwide (70%). They are distinguished by both exceptional corrosion resistance and high strength properties.

Stainless steels with martensitic and ferritic-martensitic structure

They are characterized by a needle-like carbon structure, which makes them the strongest of all types of stainless alloys. In addition, stainless steels in this category are very wear-resistant and can be operated at high temperatures. Their composition, which is also important, contains a minimum amount of harmful impurities.

Stainless steel grades with a combined structure

Such steels, which can have an austenitic-ferritic or austenitic-martensitic structure, are the product of innovative technologies and optimally combine all the advantages of other types of alloys.

Knowing the structure of a certain grade of stainless steel, which forms its main characteristics, is important in order to optimally select it to solve the required problems.

Stainless steel cookware

Decoding stainless steel grades

In order to choose the right grade of corrosion-resistant steel for certain purposes, it is most convenient to use special reference books.

They provide information about all possible designation options for such alloys in different countries of the world. Among the huge variety of brands, we can highlight those that are most widespread among specialists in many countries around the world.

These include the following grades of stainless steels with an austenitic structure.

• 10Х13Н17М3Т, 10Х13Н17М2Т: these grades are distinguished by, in addition to exceptional corrosion and thermal resistance, a good ability to form welded joints. Thanks to these qualities, products made from alloys of these brands can be successfully operated at elevated temperatures and come into contact even with very aggressive environments. The constituent elements of such alloys, which determine their unique characteristics, are: chromium (16-18%), molybdenum (2-3%), nickel (12-14%), carbon (0.1%), silicon (0. 8%), copper (0.3%), titanium (0.7%), manganese (2%), sulfur (0.02%), phosphorus (0.035%). In other countries, these brands are designated differently, in particular: in China - OCr18Ni12Mo2Ti, in Japan - SUS316Ti, in the USA - 316Ti, in France - Z6CNDT17-12.
• 08Х18Н10, 08Х18Н9: these steel grades are used for the production of pipes of various sections, elements of furnace equipment, and at chemical industry enterprises. The composition of such steels includes: chromium (17-19%), titanium (0.5%), nickel (8-10%), carbon (0.8%).

Stainless steel ducts

• 10Х23Н18: stainless steels of this grade belong to the heat-resistant category. When using them, be aware that they may become brittle when tempered. The composition of steels of this grade includes: chromium (22-25%), nickel (17-20%), manganese (2%), silicon (1%).
• 08Х18Н10Т: stainless steel products of this brand are welded well even without preheating and do not lose their corrosion resistance even at high temperatures. The insufficiently high strength that steels of this grade are characterized by is easily improved by heat treatment, which is recommended by GOST 5632-72.
• 06ХН28МДТ: a unique grade of steel, welded structures from which can be successfully operated even in very aggressive environments. The composition of this grade of corrosion-resistant steel includes: chromium (22-25%), nickel (26-29%), copper (2.5-3.5%).
• 12Х18Н10Т: products made from this grade of steel, characterized by high thermal stability and exceptional impact toughness, are mainly used in oil refining enterprises, in the chemical, pulp and paper industries, as well as in construction.

Correspondence table of the main grades of stainless steels and chemical composition

Stainless steel grades with a martensitic structure include: 40Х13, 20Х13, 12Х13, 30Х13.

Products made from these grades of stainless steel cannot be joined by welding; they are mainly used to make cutting and measuring tools and spring elements.

The great advantages of such products are the almost complete absence of internal defects (flocks) in them; moreover, they do not become more fragile after tempering.

Corrosion-resistant steels with a ferritic structure include: 08Х17, 08Х18Т1, 08Х13. It is not recommended to manufacture parts from these grades of steel that will experience significant shock loads and operate at low temperatures.

In order to understand the qualitative and quantitative composition of stainless steel, it is enough to decipher its brand. The algorithm for this decryption is quite simple:

• using the first number in the steel grade, the quantitative content of the main element after iron is determined - carbon (calculated in hundredths of a percent);
• The content of other elements in the steel (calculated in whole percentages) is determined by the numbers behind the letters by which such elements are designated (X - chromium, H - nickel, M - molybdenum, etc.).

A wide range of stainless steel grades allows you to find the best option for yourself. It should be borne in mind that certain types of stainless steel can be interchanged within certain limits. If you encounter difficulties when choosing steel, you need to contact technical consultants of specialized companies.

Source: https://varimtutru.com/nikelirovannaya-stal-ili-nerzhaveyka-chto-luchshe/

Stainless steel

Stainless steel is an alloy of iron and carbon to which a certain chemical element has been added that increases the resistance of the steel to spontaneous destruction, i.e. to different types of corrosion. There are three types of stainless steel:

1. corrosion resistant;
2. heat resistant;
3. heat resistant.

According to the chemical composition, i.e. Depending on what is added to the steel to increase corrosion resistance, stainless steel is also divided into three types. There are:

1. chromium,
2. chromium-nickel
3. chromium-manganese-nickel stainless steel.

History of the invention of stainless steel

At the beginning of the 20th century, the English experimental scientist Harry Brearley noticed that metal that includes chromium does not corrode and does not rust. This scientist filed a patent for the material, which he called martensitic steel.

Experts now know it as AISI420 steel. Before Harry Brearley, a lot of work was carried out to search for stainless metal.

A major contribution to this research was made by the German scientist Monnartz Phillip and the Frenchman Gillette Leon, who tried to invent various types of stainless steel.

Harry Brearley (02/18/1871 – 07/14/1948)

Stainless steel - application

Stainless steel has changed many areas of production, which have experienced various changes and growth in their activities in connection with this. Practical and durable metal has received great recognition in medicine and in the food industry. In the food industry, all equipment is necessarily made of stainless metal. Well, a person comes across such little things as forks, spoons, knives several times a day.

Stainless steel cookware

In modern architecture and construction, it is impossible to do without elements made of stainless steel. In any interior, if this metal is present, the design will be harmonious and fantastic. Stainless steel goes well with materials such as brick, stone, glass.

This metal is not only convenient for long-term use, but also gives the building a beautiful appearance with its beautiful shine. It is very popular to use stainless steel for decorative items in shopping centers, restaurants, and cafes.

Such fragments give objects a solid, stable and reliable status, and are also practical, since the metal does not corrode.

Stainless steel, due to its resistance to aggressive environments, finds its use in the chemical industry in mechanical engineering, in the production of various mechanical components and assemblies.

Stainless steel containers in production

Source: http://www.alto-lab.ru/for-housewives/nerzhaveyushhaya-stal/

Stainless steel grades - classification, interpretation

Steel, which has anti-corrosion properties, is actively used in many fields of activity; It has gained such high popularity because it has qualities that are unattainable for many other metal alloys.

The first grades of stainless steel appeared in 1913, when Harry Brearley invented an alloy with exceptional resistance to the formation and development of corrosion.

It was from this moment, which became a major milestone in the development of metallurgical and many other industries around the world, that the history of stainless steel begins, actively and successfully used by man for more than 100 years.

Finished stainless steel rolls

History of stainless steel | The emergence of stainless steel in industry

The history of stainless steel began more than two centuries ago, in 1797, when the chemist Vauquelin, while studying the properties of chromium, discovered a unique feature of this metal - extreme resistance to acid. Many years passed before this important discovery found practical application in various areas of our lives.

The main version is official

The official creator of stainless steel is considered to be metallurgist Harry Brearley (Brearley), an English researcher who headed a laboratory for the study of metals at the beginning of the 20th century. The laboratory's activities were supervised by Sheffield steel companies, whose primary purpose was to study steel alloys intended for casting weapon barrels.

Trying to create an alloy with high strength and heat-resistant characteristics, Brearley added various additives to iron and experimentally studied the resulting properties of the metal. Unsuccessful samples were stored right there in the laboratory and rusted over time. One day, a scientist noticed that one of the blanks, cast more than a month ago, did not become rusty, but retained its original shine.

This composition, discovered by chance, was taken as the basis for modern stainless alloys. It consisted of iron, chromium, manganese, carbon and silicon. It was Harry Brearley who in 1913 received a patent for the first martensitic alloy, which became the predecessor of the modern AISI 420 brand.

Other stainless metal researchers

But not everyone agrees with Brearley's primacy in the history of the invention of stainless steel. In 1821, French researcher Pierre Berthier proved that adding nickel to the alloy made it resistant to rust. However, this predecessor of stainless steel had another problem.

The material turned out to be very fragile, which was a serious disadvantage for its use. Subsequently, a number of authors worked on the original recipe.

One of them, Elwood Haynes, applied for a patent a year earlier than Brearley, but was able to receive it only seven years later.

In 1904, Gillette used an alloy in the production of a razor, the chemical properties of which resisted corrosion processes well. The German scientist Philipp Monnartz published his results of studying corrosion-resistant steel in 1911. E. Maurer and B. Strauss received a patent in 1912 for an austenitic stainless steel composition with a high content of chromium and nickel.

However, Brearley was recognized as the founder and principal investigator of further theoretical and practical developments in the field of stainless steel.

Bringing stainless steel to the mass market

Brearley continued his experiments with an unusual preparation and found that the resulting composition was resistant to acids. There is no doubt that the new steel had great potential. Despite the fact that it was not used in weapons production, it could be successfully used in other areas.

The scientist suggested that leading metallurgical companies use rolled steel with new chemical properties for the manufacture of cutlery, but did not meet with interest from manufacturers. They considered the material unpromising, expensive to produce, and refused to manufacture the product or promote it on the market. The future fate of stainless steel was in great doubt.

But a year later, E. Stewart, an employee of a cutlery manufacturing company, agreed to produce a test batch of knives as an experiment. The product was highly praised by consumers and, after improving manufacturing technology, the Sheffield company recognized the good prospects for the new invention in the market.

Production picked up speed. Just a few years later, patents were received for the invention in Europe, the USA and Canada. As a result of the collaboration between Brearley and Haynes, an international corporation was created for the production and manufacture of martensitic and ferritic stainless steel products.

Popularization of stainless alloys

Stainless steel became widely known among the world community just over 100 years ago, after the publication of an article in the New York Times about a technological breakthrough made by a Sheffield company. According to the British manufacturer, the new type of product is not susceptible to corrosion, does not lose its original shine under the influence of water and acids, does not become stained and does not fade over time.

Initially, the new alloy was intended for the manufacture of cutlery, but after a few years it began to be used in a wide variety of industries and mechanical engineering.

Types of Stainless Steels

As a result of numerous experiments with the basic chemical composition and ratio of additives, the main groups of alloys were identified:

• Ferritic - low carbon, with a high chromium content (up to 30%), ductile and easy to process.
• Martensitic - chromium-carbon compositions with high strength.
• Austenitic (chromium-nickel) are non-magnetic alloys with anti-corrosion properties superior to ferritic and martensitic ones.
• Combined - combining the properties of austenitic and ferritic steels.

Stainless steel today – main areas of use

It’s hard to imagine modern life without stainless steel. When stainless steel appeared in industry, it simplified many technological processes and helped modernize production, bringing it to a completely new level of development.

Food industry

Durable and practical metal is widely used in the food industry. Equipment, production lines, containers and reservoirs for transporting and storing products, cutlery and dishes - the role of stainless steel in this area is truly enormous.

Medicine

In medicine, stainless steel has solved the problems of processing and hygiene of instruments and work surfaces. It is used in the manufacture of medical equipment and furniture, consumables, and instruments.

Mechanical engineering

The main purpose of corrosion-resistant steel in this industry is the production of parts, devices and assemblies for machine tool building, transport engineering, and industrial needs.

Chemical industry

In the petrochemical industry, corrosion-resistant steels are used in the production of reactors, pipes, units, units, structures, and tanks, which are subject to high requirements for strength and resistance to aggressive environments.

Architecture and construction

In architecture and construction, decorative and finishing elements and supporting structures are made from stainless alloys. The material combines perfectly with wood, glass, stone and will look great in any interior.

Space and aviation

In the aerospace industry, the material is indispensable for creating special equipment, instruments, and parts.

Over the years, the possibilities for using anti-corrosion alloys have only expanded. Properly selected and processed metal products are an ideal material for long-term and trouble-free use. Currently, there are dozens of varieties of rolled stainless steel, the properties of which are determined by the requirements of the relevant industry.

Source: https://indust.by/info/articles/metalloprokat/istoriya-nerzhaveyushchey-stali/

History of stainless steel

20.11.14

Today we will tell you about the history of the creation of one of the most popular materials on the global metal market - stainless steel. The idea of ​​how to eliminate the most important problem of any metal alloy has excited the minds of inventors and visionaries for centuries. The most daring attempts were made, but it was possible to get any closer to solving the problem only in the second half of the 19th century.

It’s worth saying right away that scientists and engineers from various countries were close to solving this problem, and the question of who succeeded first is still not completely closed. Therefore, we will try to mention in our essay all the most successful attempts, and we will leave the right to decide to the reader.

First successes

It’s worth starting, perhaps, with the Englishmen Stoddard and Faraday, as well as their French colleague Pierre Berthier. They noticed that adding chromium to iron made the alloy resistant to acids. Initial experiments were unsuccessful due to the fact that the inventors hesitated for a long time to increase the dose of chromium, and then finally stopped due to the excessive carbon content in the alloy.

The above error was corrected only half a century later, in the early 70s. 19th century.

This was done by the British Woods and Clark, who patented an alloy consisting of a third of chromium, and the success was developed by the Frenchman Brustlein, who was the first to establish that the percentage of carbon in the alloy should not exceed 0.15.

However, this conclusion remained solely on paper. This was physically achieved only in 1895 by the German inventor Hans Goldschmit, who first carried out the aluminothermy process.

Then inventions began to pour out like from a basket.

1904 - the first alloys were obtained that coincided with some modern standards (L. Gullit);

1909 - stainless steel appeared, which today has a standard of 430 (A. Portevin);

1911 – a formula with a chromium content of 10.5% was first developed.

Invention of Harry Brierley

The history of the invention of stainless steel cannot be told without mentioning the name of Harry Brierley. In 1912, this British engineer received an order to invent a way to extend the life of gun barrels. And Harry began his experiments with the goal of defeating erosion, not corrosion.

As with many stories of great inventions, chance intervened. On August 13, 1913, the Briton received an alloy with 12.8% chromium and 0.24% carbon. According to legend, the engineer, dissatisfied with the result, simply threw the sample away and only after a while noticed that it was not subject to the corrosion process.

However, most scientists consider this day to be the date of the invention of stainless steel.

Source: http://ntc-bulat.ru/history-steel