What type of stainless steel is food grade?

Food grade stainless steel: GOST. How to identify food grade stainless steel? What is the difference between food grade stainless steel and technical stainless steel?

Stainless steel is the most popular material from which containers and utensils that come into contact with food are made. Stainless steel has good anti-corrosion properties, durability and low weight. However, it is worth considering that this material is not always resistant to aggressive environments; in this case, special food-grade formulations are used.

Of course, it is best to store food in steel or glass containers, since the foam propylene that is popular today does not meet all the necessary requirements. In addition, its service life is much shorter than that of products made of steel.

Many people are interested in how to distinguish food-grade stainless steel from material that is unsuitable for storing food? To answer this question, it is worth considering the advantages, features and classification of this metal.

Advantages of food grade stainless steel

If we talk about the advantages of food-grade stainless steel, it is worth highlighting:

• environmental safety of the material;
• ease of maintenance;
• resistance of the material to most chemicals;
• wear resistance;
• compliance with standards for the dissolution of heavy metals.

In addition, it has long been proven that instead of frying pans with a non-stick coating, it is much healthier to use utensils made from food-grade stainless steel. The best cooking stoves and refrigerator surfaces are made from the same material.

Which stainless steel is considered food grade?

Stainless steel, suitable for storing and preparing food, is a highly alloyed metal containing 25% chromium. It is thanks to this chemical element that alloys are famous for their anti-corrosion characteristics. In case of contact with an aggressive environment, a special protective film is formed on the metal surface. Thanks to this surface layer, the metal does not rust.

In addition, titanium, molybdenum, nickel and other chemical components are added to food-grade stainless steel, which further increase the anti-corrosion properties of the material.

GOST and stainless steel grades

If we talk about state standards, they do not stipulate the rules related to stainless steel. This is why experts find it difficult to answer which material is recommended for use in the food industry. In turn, the manufacturers of this stainless metal respond that regardless of its brand, it is suitable for food products.

Do the standards really say nothing about food grade stainless steel? GOST 5632-72 is perhaps the closest regulatory document that can be used when choosing the best alloy for household use. This State Standard refers to grades of high-alloy steel and corrosion-resistant and heat-resistant alloys. Let's take a closer look at this classification.

08Х18Н10

Austenitic, corrosion-resistant stainless steel is produced under this brand. The European analogue is AISI 304. This material is not magnetic. It is used in all industrial and commercial sectors.

This material has a low price and good quality. It is often used in the food industry, but only on the condition that the metal does not come into contact with caustic soda or sulfamine solutions.

12Х18Н10Т

The European analogue of this brand is AISI 321. This heat-resistant steel is also not magnetic. Stainless steel of this brand is often used in the manufacture of elements of furnace fittings, heat exchangers and exhaust manifolds. The thing is that this steel is suitable for use at high temperatures from 600 to 800 degrees.

08Х13

The European analogue of this material is AISI 409. This steel is widely used in the production of kitchen utensils and cutlery. This food grade stainless steel is most often found in stores. The material gained such popularity due to its high degree of adhesion and ability to adapt to different operating conditions.

This dish can be safely heated or stored in the freezer.

20Х13-40Х13

Steel of this type belongs to the category of composite materials, so it is often used in the manufacture of household and industrial sinks, as well as for the production of utensils for hygienic or thermal processing of food.

The European analogue of this brand is AISI 420. If the cookware bears one of these markings, then you can safely buy it for household use.

This stainless steel does not rust, tolerates sudden changes in temperature, and is also a fairly plastic and wear-resistant material.

12Х13

In Europe, this material is produced with the AISI 410 marking. Steel of this type is more often used in the production of equipment for winemaking, food processing and alcohol production. In addition, this material is characterized by increased heat resistance in mildly aggressive environments.

08Х17

In Europe, this steel is produced under the brand name AISI 430. This stainless steel is indispensable if the food in the cookware is subjected to heat treatment. This type of steel has the highest strength. However, this material quickly deforms in a sulfur environment. At the same time, stainless steel does not rust and can withstand mechanical loads. It is recommended to buy frying pans from this material, since 08X17 is characterized by a high thermal conductivity coefficient.

All other materials are used in special conditions, their cost is much higher. However, not all stainless steel can be safely used for cooking and storing food. In order not to delve into how food-grade stainless steel differs from technical stainless steel, it is much easier to read a few useful recommendations. They will allow you to quickly determine whether a given material is suitable for food. This is useful to know for every consumer concerned about their health.

How to distinguish food grade stainless steel from technical grade?

To determine the composition of the anti-corrosion alloy, as well as the possibility of its use in everyday life, you can write down the brands that were listed above. If such markings are on the utensils, then they are suitable for preparing and storing food.

But sometimes it happens that in front of your eyes is a material of an unknown brand, and the seller insists that this alloy is absolutely environmentally friendly and cannot harm humans. In this case, it is enough to place the metal in a 2% vinegar solution and wait for the reaction. If the shade of the material has changed, it has become dark, then it is better not to use it. The constancy of color indicates that the stainless steel is indeed food grade. It can be used.

There is another method that consumers often use after reading information on how to identify food-grade stainless steel. They use a magnet for this. But it is worth understanding that this method is completely ineffective, since stainless steel can be magnetic or non-magnetic. Accordingly, using a magnet will not help in any way determine whether the material can be used for food.

To choose the best metal, you should study the information about the product and ask the seller for accompanying documents. Any utensils must be manufactured in accordance with certain standards and requirements. If there is no marking on the product, then it is better to refuse such a product. Otherwise, you can purchase low-quality utensils that are dangerous to human health.

Source: https://autogear.ru/article/321/576/nerjaveyka-pischevaya-gost-kak-opredelit-pischevuyu-nerjaveyku-chem-otlichaetsya-pischevaya-nerjaveyka-ot-tehnicheskoy/

Food grade stainless steel

When creating products that may come into contact with food and liquids during operation, food grade stainless steel is often used. The properties of this material determine its wide distribution. The main property is related to corrosion resistance. A wide variety of blanks are supplied for sale, most often in the form of sheets.

Food grade stainless steel

General characteristics of food steel

The main characteristics of food grade stainless steel are higher than regular ones. This is due to the fact that not every metal can withstand the conditions under which food is transported and stored. That is why, over a long period, developments have been carried out to obtain a material with exceptional performance qualities.

Modern food grade stainless steel is characterized by the following features:

1. Aesthetically attractive appearance. However, it remains practically unchanged over a long period.
2. The differences between food-grade stainless steel and technical stainless steel are that the former is produced in compliance with strict hygienic and toxicological requirements.
3. Environmental Safety. The surface does not interact with the environment.
4. Ease of maintenance. Stainless steel can be cleaned quickly if necessary and does not require special chemicals.
5. The surface film can withstand aggressive influences.

Recently, food grade steel is often used in the manufacture of household products. In addition, sheet material is used for lining the interior of ovens or stoves. High performance characteristics determine that stainless steel can last for a long period.

Food grade stainless steel sheet

A fairly common question is how to distinguish food grade stainless steel from technical grade stainless steel. The category of metals under consideration includes alloys that contain about 27% chromium.

By increasing the concentration of this chemical, an oxide film is formed on the surface, which significantly increases the corrosion resistance of the metal.

How to identify food grade stainless steel? As a rule, the difference lies in the concentration of certain elements in the composition:

1. At a certain concentration of chromium and calcium, the resistance of the surface to water vapor can be increased. At the same time, anti-corrosion properties can be maintained at temperatures up to 1150 °C.
2. The composition may also include nickel, which increases the resistance of the surface to nitric or other acids.
3. Molybdenum increases the resistance of the metal to acetic and sulfuric acid.
4. In some cases, copper is added, due to which the metal becomes more resistant to corrosion and stretching.
5. Silicon protects the material from the action of sulfuric and hydrochloric acid.

It is worth considering that a high concentration of alloying elements can negatively affect the basic mechanical characteristics of the metal. Therefore, when choosing a more suitable stainless steel, the conditions under which it will be used are taken into account.

As previously noted, the scope of application of stainless steel has been significantly expanded. Stainless steel grade for the food industry can be used in the production of the following products:

1. Cutlery and crockery.
2. Various electrical goods intended for cooking.
3. Equipment for the food industry: storage, transportation, preparation.
4. In some cases, sheets of metal are used to line the interior surface of the cargo compartment of a vehicle.

Stainless steel kettleStainless steel kitchen set

The composition can include a variety of chemical elements, due to which not only corrosion resistance increases, but also strength and hardness.

When choosing the most suitable alloy, attention is paid to how long the product will be in contact with an aggressive environment. Some products can be created from an alloy that is less resistant to corrosion, but still has good strength.

Chemical composition of AISI 304 steelPhysical properties of AISI 304 steel

Food grade stainless steel steel grade AISI 304 is the most widely used. This is due to the fact that 08×18N10 is characterized by low cost and high resistance to various chemicals and substances. In addition, the following qualities are taken into account:

1. A good degree of weldability, which simplifies the process of producing various products.
2. High strength and increased machinability with low heat.
3. It is possible to carry out electric polishing to obtain the highest quality surface.
4. High resistance to intercrystalline corrosion. It can significantly reduce the strength of the material and its other qualities.

Another popular brand of food grade stainless steel 08×13 is characterized by universal properties. It is used in the manufacture of various products, including those used in everyday life. A heat treatment container is often created using a 20×13 grade, which is characterized by ductility and increased wear resistance. In addition, when exposed to heat, the surface does not lose its corrosion resistance.

Chemical composition of steel 08Х18Н10Physical properties of steel 08Х18Н10

Industries that require metals with increased corrosion resistance include winemaking or alcohol production, and waste recycling. In this case, steel grade 12×13 is used. It is characterized by the following properties:

1. High heat resistance. During operation, stainless steel can heat up to temperatures above 100 °C, due to which the basic properties change.
2. Protection from exposure to mildly aggressive environments.
3. Good toughness

Stainless steel is often used in the manufacture of containers for industrial and household purposes, in which food is heated to high temperatures. The 08×17 brand is suitable for this. This alloy has the following properties:

1. Corrosion resistance at elevated temperatures. Some food-grade stainless steels cannot withstand high heat, resulting in corrosion on the surface.
2. High mechanical properties. The created products can last a long time under various operating conditions.
3. Thermal conductivity. As a rule, heating of the contents occurs from the outside. That is why thermal conductivity is considered the most important parameter.
4. With sufficient strength, high ductility is also maintained.

Chemical composition of food grade stainless steel 20X13

Universal ones are most common in the production of household appliances. This group includes alloy 08×17T, which is most often supplied to production in the form of rolled sheets.

Features of marking and GOSTs

Labeling of food grade stainless steel is carried out in accordance with the established rules in GOST. As a rule, when designating an alloy, the concentration of the main alloyed elements is indicated.

Download GOST 5632-2014

Among the marking features, we note the following points:

1. The first number indicates the concentration of carbon - the main element that determines the strength and hardness of the alloy.
2. Certain symbols are used to designate alloying elements. For each, the concentration is indicated as a percentage.
3. If a number is not placed in front of the symbol, then the concentration of the chemical element is less than one percent.

Food grade stainless steel in industry

In addition, food grade stainless steel (GOST defines sanitary and technical standards) may contain other impurities that are not indicated when labeling. An example is sulfur and phosphorus - both elements are included in the composition of almost all metals, they are harmful impurities, and with an increase in the amount of which the alloy loses its properties.

Source: https://stankiexpert.ru/spravochnik/materialovedenie/pishchevaya-nerzhaveyushchaya-stal.html

What is the difference between food grade stainless steel and technical stainless steel?

The food industry is one of the few represented in any country on any continent.

The main factors faced by the equipment involved in this industry are the product environment, which has a pronounced corrosive activity, the use of chemically active substances for disinfection and hygiene of processes, high temperatures, high rates of pressure change and the use of mechanical mixing. These factors have led to the widespread use of equipment made of stainless alloys in the shops of food factories.

Stainless steel serves not only as a material for making tableware, but also for hygienic and comfortable furniture for catering facilities

Features and areas of application of food steel

Stainless steel for the food industry, used today in production, must have a special chemical composition and be an alloy of many properties. The chemical composition of food grade stainless steel determines the main ones:

• High resistance to food environments over a wide temperature range
• Stability and resistance to aggression of substances in welds
• Structural rigidity, weldability
• Neutral behavior towards chemical reagents
• Resistance to mechanical stress
• Compliance with sanitary standards and environmental standards

To ensure that the above points are met, it is important to pay attention to the chromium content of steel. The use of alloys containing less than 17% of this element is fraught with troubles and premature failure of expensive equipment.

Chromium, when combined with iron, is able to create on the surface, during crystallization, a protective layer that resists external adverse factors.

Other elements, no less important, when introduced into the alloy, create additional properties and characteristics:

1. Ni – Nickel, along with chromium, contributes to corrosion resistance.
2. Ti – titanium resists rust of welds and areas of products heated to 450 – 800 degrees.
3. Mo – molybdenum increases resistance to pitting corrosion.

The lack of state standards and regulations for food-grade stainless steel leads to a free interpretation of suitable steels, based on advice and previous experience using certain grades. The term “food grade” stainless steel is conditional and is determined by the specifics of operation and use in the relevant production.

Interesting information: stainless steel is not the only metal for the food industry. But, as a rule, other metals are allowed in one industry and prohibited in others. There is a ban on copper in lactic acid production.

In the production of alcohol, beer, and confectionery, copper is the best material. Aluminum, on the contrary, is certified for the milk production process, but is prohibited for the preparation of dairy food products.

Stainless steel is the industry's most versatile material.

Food grade stainless steel

Research and testing in the field of hygiene, industrial sanitation, structural properties, technological features of the alloys that were used for the production of wine and vinegar helped to find the most satisfying brands. These products are the most aggressive in industry (exposure to acids, yeast, oxygen).

• 12x18n9t, 08x21n6m2t, 08x21n5t, 08x17t, 08x18g8n2t, 12x21n5t - steel grades suitable for the production of individual elements or units operating in wine environments, must, in contact with winemaking waste, involved in the sugar (beet processing), alcoholic beverage, bakery, confectionery industries . From the markings, it is obvious that the main alloys are nickel and titanium.
• 12x13, 20x13, 12x17, 14x17n2 steel grades are suitable for containers and elements with short-term storage of wort, alcohol and other aggressive products.
• Steels 08x18g8n2m2t, 08x23n28m2t, 40x25n, due to their good structural characteristics, are used for components, assemblies, containers, tank trucks for transporting alcohol, dairy products, wine and their storage and aging.

Imported analogues of food grade stainless steel

The modern market is saturated with foreign-made products. Food industry enterprises and manufacturers of equipment for it need to understand the features of foreign classifications. Germany and Europe work with the DIN system, but more and more recently they are leaning towards the American AISI classifier.

Steel grades AISI 304, AISI 304L, AISI430, AISI316, AISI-316Ti, AISI321 are widely used. Unscrupulous traders offer manufacturers who use food grade stainless steel in their production these grades equivalent to 08x18n10t, 12x18n10t, x18n9t.

It should be taken into account that steel grades AISI304, AISI430, AISI316 do not contain titanium. The absence of such an element can lead to intergranular corrosion in welding seams, soldering and bending areas. When using such steels for the needs of the food industry, the use of passivating pastes and solutions is mandatory.

Failure to take such measures will lead to the appearance of rusty streaks already at the stage of using sanitary and hygienic products.

Surface quality and roughness

For the food industry, the surface of the metal is important. AISI provides the following types of surface treatments:

• 1D - hot rolled, pickled and heat treated. The surface has a matte sheen and is slightly rough.
• 2B – cold rolled, pickled, heat treated and tempered. Characterized by a matte surface, high smoothness and gloss with gloss. One of the most common in modern industry.
• BA – cold rolled, using special rolls, followed by bright annealing. Has a mirror surface.
• 4N - polished stainless steel surface in various ways.
• PE - sheet metal has a protective film on one side.

Interesting information: How to identify the difference. If there is a need to test stainless steel, it is necessary to place the sample in a saline or 2% vinegar solution and leave for several days.

If the steel has not darkened, it can be used for production. The second method is to sand an area of ​​metal with sandpaper and apply a solution of copper sulfate to this place.

The absence of a red film indicates that the alloy belongs to stainless steel grades.

Operational Requirements

During the manufacture and use of equipment, steel is exposed to all kinds of influences. There is a danger of changes in the surface structure, which leads to a deterioration in the declared indicators and a decrease in performance characteristics.

Compliance with the following requirements for the production and operation of food grade stainless steel products will extend their life and be safe when preparing any food, in any quantity.

• During design and production, contact of dissimilar metals must be avoided. If such contact is unavoidable, insulating gaskets should be used.
• Products intended for designated industries must be designed and manufactured without narrow, difficult-to-reach cavities. Such defects lead to the retention of various substances and will allow the residues of cleaning and washing chemicals to concentrate. This fact explains why welds must be butt welds. Overlapping connections of elements are strictly prohibited.
• If there is no urgent need, minimize the time of interaction of steel with high-temperature concentrates that contain sodium chloride, solutions containing acids, even at low temperatures, disinfecting and cleaning chemicals based on chlorine.
• Avoid food drying on metal surfaces, regardless of the nature of the food. Even neutral food can turn sour and acids will appear that destroy the surface.

From the information presented on this page, we can conclude that before choosing a specific grade of stainless steel for the manufacture of food industry equipment, it is necessary to conduct research and examination of the sample under conditions close to those in which it will have to be used.

Source: https://steelfactoryrus.com/chem-otlichaetsya-pischevaya-nerzhaveyka-ot-tehnicheskoy/

Main characteristics of food grade stainless steel

Equipment and containers for the food industry can be made exclusively from high-quality materials. Special conditions for storing, transporting and processing materials can cause corrosion, even in cases where stainless steel is used.

Stainless steel is widely used in the food industry

That is why food industry enterprises use exclusively food-grade stainless steel, which differs from conventional stainless steel in its higher corrosion resistance and resistance to the chemically active environment of the transported liquid.

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What is food grade steel?

Food grade stainless steel is a common name for those grades of stainless steel that demonstrate increased resistance to corrosion. It should be borne in mind that this concept is not enshrined in any regulatory document, which complicates the difficulty of choosing the necessary products.

The grade of stainless steel suitable for use in the food industry was determined experimentally. The following important pattern was identified: the longer stainless steel is in contact with a chemically active food product, the higher its corrosion resistance should be.

Only certain grades of stainless steel are suitable for use in the food industry

It was possible to establish that the most suitable for the food industry are:

• AISI 304;
• AISI 304 L;
• AISI 316;
• AISI 316 L;
• AISI 316 Ti;
• AISI 321;
• AISI 430.

For the production process associated with the processing, preparation, storage or transportation of food, any of the listed brands can be used.

But it is necessary to take into account that the AISI 304, AISI 316 and AISI 430 grades are produced without the addition of stabilizing titanium, and therefore their resistance to chemical and mechanical influences remains quite limited.

Such steel is suitable for production under the condition of short-term contact with chemically active substances and maintaining gentle operating conditions.

Some brands of stainless steel cannot withstand prolonged contact with chemically active substances

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Main characteristics of food grade stainless steel pipes

Pipe for the food industry must meet high quality standards, including international ones. Due to its high levels of hygiene and environmental friendliness, stainless steel has become the main material for the production of equipment and containers.

A stainless steel pipe has the following quality characteristics:

• resistance to corrosion, including the weld area;
• resistance to chemically active environments;
• wear resistance;
• non-toxic;
• environmental friendliness;
• smoothness of the inner surface;
• ease of maintenance;
• compliance with the standards of migration of heavy metals in the working fluid environment.

Stainless steel contains only environmentally friendly alloying additives that do not affect the properties of the transported product.

The thickness and diameter of food grade stainless steel meets the standards

The main technical characteristics comply with European standards. They imply the following parameters:

• maximum wall thickness – 6 mm;
• minimum thickness – 1 mm;
• minimum outer diameter – 6 mm;
• maximum outer diameter – 609.6 mm.

Depending on the degree of surface treatment, the pipe can be:

• matte;
• polished;
• polished.

The pipe is also classified according to its cross-sectional shape. The following main varieties are distinguished:

• round;
• square;
• rectangular.

Rectangular stainless steel is also used in the food industry

An important advantage of stainless steel products is their low weight per linear meter. This allows the use of low-alloy steel not only in the food industry, but also in the chemical, pharmaceutical, transport and construction sectors.

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Varieties of AISI 304 / 304 L pipes

Round pipe of AISI 304 and AISI 304 L grades is called “milk” in narrow circles. This is due to the high hygiene of the pipeline and the ability to easily transport liquid and viscous substances, for example, dairy or any other aseptic products.

The main advantages of this grade of steel are:

• strength;
• ability to withstand uniform load along the entire length, including the welding seam;
• roughness less than 0.8 microns;
• roughness in the weld area – no more than 1.6 microns.

For the transportation of liquid substances, it is recommended to use AISI 304 and AISI 304 L pipes

Such unique properties are associated with an increased content of chromium and molybdenum in the composition, as well as a reduced carbon concentration. This greatly simplifies the processing and welding of products and contributes to better corrosion resistance.

Most often, such a pipe is made with a length of 6 m, however, depending on the need, it is possible to produce products of very different lengths. Also, in some cases, before sale, products are subject to additional heat treatment (annealing, etching).

European companies are the world leaders in the production of round pipelines made of stainless low-alloy steel. The products of such companies have proven themselves well:

• ILTA INOX (Italy);
• Siderinox (Italy);
• PADANA TUBI (Italy);
• Marcegaglia (Italy);
• BUTTING (Germany),
• Outokump (Finland);
• ARCELO (France);
• Inoxidables de Rabade (Spain).

When choosing round food pipes, preference should be given to European manufacturers

The main area of ​​application is the food industry, but such pipes are also used in the chemical and pharmaceutical industries.

Square products differ from others in the symmetry of their parameters. The high hygienic properties of stainless steel make it possible to use square pipes in dairy, bakery and confectionery production.

The food industry is not the only consumer of such products. High corrosion resistance, durability and impeccable appearance allow the pipes to be used for the construction of decorative structures, stair railings, bar counters and other supports.

The scope of use of rectangular stainless steel pipes is in many ways similar - this is the food industry and construction, the construction of supporting and decorative structures. One of the main reasons for using 300 series steel is the combination of affordable price and good performance.

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How is stainless steel made?

Interesting on the topic:

Source: http://VseOTrubax.com/materialy/nerzhavejka/osnovnye-xarakteristiki-pishhevoj-nerzhavejki.html

Food grade stainless steel GOST steel grade

The food industry is one of the few represented in any country on any continent.

The main factors faced by the equipment involved in this industry are the product environment, which has a pronounced corrosive activity, the use of chemically active substances for disinfection and hygiene of processes, high temperatures, high rates of pressure change and the use of mechanical mixing. These factors have led to the widespread use of equipment made of stainless alloys in the shops of food factories.

Stainless steel serves not only as a material for making tableware, but also for hygienic and comfortable furniture for catering facilities

How to choose a grade of food grade stainless steel: types and scope of use of food grade stainless steel

The production of equipment or containers that interact with food requires the selection of a specific material. Preparation, storage, transportation of food, sanitation, are most often associated with conditions where even stainless steel can be susceptible to corrosion and negatively affect the quality of food. The so-called food grade stainless steel helps solve this problem.

Food grade stainless steel is a general name for grades of stainless steel that have increased corrosion resistance . GOST does not have this definition; it is for this reason that food grade stainless steel often needs to be selected based on scattered reviews and information. What is food grade stainless steel, and how to choose the right grade of steel? First things first.

Why do you need food grade stainless steel?

The manufacture of various containers and utensils that come into contact with food products involves the selection of special materials that have special properties. Since even ordinary stainless steel, which is famous for its anti-corrosion properties, cannot always withstand aggressive chemical processes that are related to the food industry .

In these cases, the issue is resolved by using specialized food grade stainless steel compounds. It is these alloys that are best suited for the manufacture of various types of equipment for processing and storing food.

These compositions meet the highest requirements (toxicological, hygienic, aesthetic) for metals that can be used in the food industry.

Advantages of food grade stainless steel:

• environmentally friendly;
• easy to maintain;
• not afraid of most chemical environments;
• wear-resistant;
• complies with clear rules for the dissolution of heavy metals in working environments.

Stainless steel is rightfully one of the best materials for making cookware that is used in everyday life. No housewife will refuse a beautiful frying pan made of this steel, a saucepan, quite practical and elegant cutlery, and any other kitchen utensils. The surfaces of refrigerators, cookers, and so on are made from stainless steel. Today, the number of uses of stainless steel products in everyday life is constantly growing.

Manufacturers of various products and catering establishments install stainless pipes . They are also used for the manufacture of technological devices used at all stages of the food preparation process - for preparing and grinding raw materials, mixing, cooking, transporting, separating and sorting.

Which stainless steel compounds are food grade?

By “stainless steel” we usually understand a large range of high-alloy metals containing a fairly large amount of chromium (about 25 percent). It is this chemical element that gives the alloys anti-corrosion characteristics due to the fact that upon contact with an aggressive environment it forms a special protective film on the steel surface. This protective layer prevents the metal from rusting because it contains insoluble oxides.

To increase anti-corrosion properties and give metals special characteristics, other chemical elements (nickel, titanium, molybdenum, etc.) are added to stainless steel, which change the properties of the alloy.

For example, in mildly corrosive environments, you can use stainless steel at a chromium ratio of approximately 14-18 percent without worrying about rusting.

If you add a little chromium (make its amount less than 18 percent), as well as molybdenum and nickel, then this metal composition can already be used in saline solutions and other rather aggressive liquids.

In our country, there are no separate State standards and rules for “food grade stainless steel”. It is for this reason that most people find it difficult to answer which brands of stainless steel can be classified as “food grade” and which cannot.

Experts say that almost all stainless compositions existing today can, purely theoretically, be classified as those that are suitable for preparing or storing food products.

In this case, the main thing is to decide on the rules for their operation .

At catering establishments and factories where food is produced, the equipment used for these purposes is constantly exposed to the aggressive action of active and chemical substances.

Naturally, under these conditions, the stainless steel that successfully resists this aggressive influence will be food grade.

But in cases where food products are in constant and short-term contact with chemical media, other brands of stainless steel compounds may fall under the definition of food grade steel.

Common grades of food grade stainless steel

When choosing a specific grade of stainless alloy for using steel in the food industry, you first need to focus on how long this steel product will be in contact with food.

Alloys that provide maximum resistance to corrosion are used to make structures and equipment that are constantly in contact with products.

And for cutlery, for example, they usually choose “lighter” steel with significantly lower anti-corrosion properties.

Let's take a closer look at the most popular brands of food grade stainless steel today:

• 08Х13 (AISI409) is used for the production of cutlery and kitchenware. In everyday life, we are very often surrounded by objects and structures made from this particular grade of steel, which is characterized by an increased level of adaptation to various operating conditions.
• 08Х18Н10 (code AISI304) is an inexpensive and popular grade of steel, which is used for food production devices that are not in contact with active acidic sulfamic substances and caustic soda. 08Х18Н10 has a unique chemical composition, which makes it possible to perform electric polishing of stainless steel objects, their high strength qualities at low temperatures. This composition has excellent resistance to intergranular impact and is also characterized by a good level of weldability.
• 12X13 (AISI410) is the main steel for the manufacture of equipment elements that are used in the processing of food waste and winemaking, the production of alcohol and various beverages. 12Х13 has increased heat resistance under slightly aggressive conditions, increased impact strength and excellent corrosion resistance.
• 20Х13–40Х13 (AISI420) – the composition of these steel alloys is such that they can be safely used for the production of any types of sinks (both industrial and household), utensils for hygiene, as well as for the thermal processing of food. These alloys offer excellent resistance to high temperature rusting and have excellent wear resistance and elasticity characteristics.

Also very popular are items made of stainless steel 08Х17 (AISI430) . These products are indispensable in cases where it is necessary to make dishes where food will be subject to heat treatment. AISI430 steel is characterized by excellent strength and deformability, in environments that have a sulfur content, has shown a high degree of anti-corrosion resistance, has excellent mechanical characteristics and a high thermal conductivity coefficient.

It is necessary to separately note steel 08Х17Т (AISI439) , from which sinks and other sanitary fixtures, refrigeration units, as well as machines for washing clothes are made. Overall, this stainless steel composition is versatile and suitable for use under a variety of operating conditions.

Features of food grade stainless steel

Food manufacturers most often use stainless steel pipes. They must comply with the requirements and rules of the DIN11850 standard, which specifies the composition of the metal and the quality of the welded joint.

Stainless steel pipes fully meet all the high requirements, environmental friendliness and hygiene of materials used in the manufacture of equipment for the catering and food industry.

They are made from steel grades AISI316L and AISI304 , which have the following characteristics:

• resistance to aggressive chemicals;
• high resistance to corrosion along the entire perimeter of the pipe and in places of welding joints;
• non-toxic and environmentally safe;
• wear resistance;
• maintaining smoothness throughout the entire service life, which facilitates maintenance and cleaning of the equipment;
• compliance with standards and rules for the dissolution and migration of heavy metals in the working environment.

In the food industry, caustic soda or hot solutions of sulfamic acid are often used to clean equipment. In such conditions, it is best to select AISI316 stainless steel, which is more resistant to aggressive substances. For public catering and domestic conditions, when the metal does not come into contact with such solutions, you can choose AISI304 and cheaper analogues AISI430, AISI410 .

Question of price

If you need food-grade stainless steel, then its cost will be largely determined by the presence of expensive alloying compounds in the composition. The quality of surface treatment of stainless steel products is also important.

Equipment for the food industry requires higher norms and standards for stainless steel, since they are located in more aggressive environments, and if corrosion occurs, it can cause harm to large volumes of products.

Cheap food grade stainless steel can be used in public catering and everyday life .

How to tell if it is food grade stainless steel

In order to find out the composition of a stainless alloy and its suitability for corrosion resistance, you can use a guide to stainless steel grades. If you have a sample of steel of an unknown grade, its quality can be checked by placing it in a working medium or in a two percent vinegar solution for several days. Metal can be used if the steel does not darken.

The popular belief that food grade stainless steel can be identified using a magnet is incorrect. Among the grades of food grade steel there are both magnetic and non-magnetic metals. To choose the right one, do not hesitate and consult with a consultant of the company where you are going to purchase stainless steel. The better you understand the food processing processes for which you need stainless steel, the more likely you are to make the right choice.

Source: https://stanok.guru/metalloprokat/nerzhaveyuschiy-prokat/kak-pravilno-vybrat-marku-stali-pischevoy-nerzhaveyki.html

The difference between food grade stainless steel and regular stainless steel - Metals, equipment, instructions

When creating products that may come into contact with food and liquids during operation, food grade stainless steel is often used. The properties of this material determine its wide distribution. The main property is related to corrosion resistance. A wide variety of blanks are supplied for sale, most often in the form of sheets.

Food grade stainless steel

Areas of application

As previously noted, the scope of application of stainless steel has been significantly expanded. Stainless steel grade for the food industry can be used in the production of the following products:

1. Cutlery and crockery.
2. Various electrical goods intended for cooking.
3. Equipment for the food industry: storage, transportation, preparation.
4. In some cases, sheets of metal are used to line the interior surface of the cargo compartment of a vehicle.

Stainless steel kettleStainless steel kitchen set

The composition can include a variety of chemical elements, due to which not only corrosion resistance increases, but also strength and hardness.

Popular brands

When choosing the most suitable alloy, attention is paid to how long the product will be in contact with an aggressive environment. Some products can be created from an alloy that is less resistant to corrosion, but still has good strength.

Chemical composition of AISI 304 steelPhysical properties of AISI 304 steel

Food grade stainless steel steel grade AISI 304 is the most widely used. This is due to the fact that 08×18N10 is characterized by low cost and high resistance to various chemicals and substances. In addition, the following qualities are taken into account:

1. A good degree of weldability, which simplifies the process of producing various products.
2. High strength and increased machinability with low heat.
3. It is possible to carry out electric polishing to obtain the highest quality surface.
4. High resistance to intercrystalline corrosion. It can significantly reduce the strength of the material and its other qualities.

Another popular brand of food grade stainless steel 08×13 is characterized by universal properties. It is used in the manufacture of various products, including those used in everyday life.

A heat treatment container is often created using a 20×13 grade, which is characterized by ductility and increased wear resistance.

In addition, when exposed to heat, the surface does not lose its corrosion resistance.

Chemical composition of steel 08Х18Н10Physical properties of steel 08Х18Н10

Industries that require metals with increased corrosion resistance include winemaking or alcohol production, and waste recycling. In this case, steel grade 12×13 is used. It is characterized by the following properties:

1. High heat resistance. During operation, stainless steel can heat up to temperatures above 100 °C, due to which the basic properties change.
2. Protection from exposure to mildly aggressive environments.
3. Good toughness

Stainless steel is often used in the manufacture of containers for industrial and household purposes, in which food is heated to high temperatures. The 08×17 brand is suitable for this. This alloy has the following properties:

1. Corrosion resistance at elevated temperatures. Some food-grade stainless steels cannot withstand high heat, resulting in corrosion on the surface.
2. High mechanical properties. The created products can last a long time under various operating conditions.
3. Thermal conductivity. As a rule, heating of the contents occurs from the outside. That is why thermal conductivity is considered the most important parameter.
4. With sufficient strength, high ductility is also maintained.

Chemical composition of food grade stainless steel 20X13

Universal ones are most common in the production of household appliances. This group includes alloy 08×17T, which is most often supplied to production in the form of rolled sheets.

Which stainless steel is magnetic and why which is food grade?

Among the main properties of a metal, the degree of magnetism is distinguished. Recently, there is simply a huge number of stainless steels, the performance characteristics of which can differ significantly. In many ways, the property under consideration depends on the chemical composition of the alloy. It is quite difficult to independently check the degree of magnetism, since it can vary depending on operating conditions.

What determine the magnetic properties of materials?

To determine the magnetic properties of stainless steel and other alloys, a certain formula is used, which reflects the proportionality coefficient and magnetic susceptibility. Depending on the type of factor used, stainless steel falls into one of several groups:

1. When the coefficient is above zero, the material belongs to the group of paramagnets.
2. When using zero, stainless steel is diamagnetic.
3. Ferromagnets are characterized by good magnetic susceptibility. This group includes nickel, cadmium and iron.

Magnetic properties of stainless steel

Stainless steel becomes magnetic when exposed to a certain field. Such a reaction is associated with the structural features of the alloy, and to some extent, with the chemical composition. Some substances are characterized by reacting to the influence of a magnet.

Stainless steels with good magnetic properties

The magnetic properties of stainless steel largely depend on the structure of the material. They manifest themselves most in the following cases:

1. Martensite is characterized by good magnetic properties and is ferrimagnetic in its pure form. This kind of stainless steel is extremely rare, since it is quite difficult to maintain a pure chemical composition. Like conventional carbon versions, this one can be improved by hardening or tempering. This metal is widely used not only in industry, but also in everyday life. The most widely used brands are: 20X13 and 40X13. They can be subjected to mechanical action, grinding or polishing, as well as various heat treatments. Features of the chemical composition include an increased concentration of chromium and carbon. 20Х17Н2 is another stainless steel, which is characterized by a high concentration of chromium. Due to this, the structure becomes more resistant to moisture and some aggressive agents. Despite the large number of alloying elements, spain is weldable and can be hot or cold forged.
2. Ferrite, depending on the degree of heating, can take two forms: ferromagnetic and paramagnetic. The chemical composition of such materials contains less carbon, making them softer and easier to process. This group includes stainless steel 08Х13, which is actively used in the food industry. In addition, this group includes AISI 430, which is used in food production plants.
3. Martensitic-ferritic alloys are characterized by very attractive performance properties. Alloy 12X13 has a similar structure. Like previous metals, this one can be subjected to mechanical and thermochemical processing.

The above information indicates that the martensitic structure has the most pronounced magnetic properties.

When choosing an alloy, it should be taken into account that not all stainless steels are resistant to mechanical damage. Even minor impacts can damage the surface layer. Despite the fact that the chromium film can be restored upon contact with oxygen, new alloys have been produced that are characterized by increased mechanical stability.

Read also: Sharpener for tungsten electrodes

Another classification of metals involves their division into the following groups:

1. Highly resistant to acids.
2. Heat-resistant version
3. Food grade stainless steel.

Heat resistant stainless steel

Material marking is carried out using alphanumeric designations. Each symbol is used to designate a specific chemical element, the number indicates the concentration. Other countries have their own specific standards for naming metal.

Non-magnetic stainless steels

There are quite a large number of metals that do not have magnetic properties. They contain nickel and manganese. The following groups of alloys are distinguished:

1. Austenites are the most widely used. This group includes 08Х18Н10 and 10Х17Н13М2Т. These metals are actively used in the manufacture of various products in the food industry, for example, cutlery and dishes. Increased corrosion properties are maintained in almost any operating environment.
2. Austenitic-ferritic stainless steels 08Х22Н6Т and 08Х21Н6М2Т are characterized by an increased concentration of chromium and some other alloying elements. To change the basic characteristics, other chemical elements are also included in the composition.

Non-magnetic stainless steel is selected when the resulting product should not respond to the influence of a magnetic field.

The choice of stainless steel can be made not only taking into account the degree of magnetism, but also the following points:

1. Weldability. Some versions need to be preheated, others weld well even when cold.
2. Ductility is taken into account when choosing a material for cold and hot stamping. A sufficiently high ductility index determines that it is possible to stamp metal sheets in a cold state.
3. Corrosion resistance when exposed to high temperatures. Many metals lose their characteristics when exposed to strong heat, including corrosion resistance.
4. Price is also an important factor. Metals can have high performance characteristics, but due to their high cost, their use for the production of some products is impractical.
5. Degree of machinability. Often, workpieces are supplied for cutting on special equipment. Due to the high concentration of carbon, hardness increases and the surface treatment process becomes more complicated.
6. Heat resistance is also an important quality that is considered when choosing a material. With good heat resistance, the manufactured product does not lose its strength and hardness when exposed to high temperatures.

Some brands are subjected to heat treatment, which increases the strength and hardness of the surface.

When tempering is carried out, the structure becomes more plastic and resistant to variable loads.

How to determine whether magnetic or non-magnetic steel is stainless?

As previously noted, it is possible to determine whether stainless steel is magnetic without the use of special equipment. Among the features of the procedure, we note the following points:

1. The test area should be polished to a high shine. Hand tools and special materials can be used for this.
2. A few drops of concentrated copper sulfate are applied to the cleaned area.
3. If the metal is stainless steel, then a red coating will appear on the surface.

Determination of magnetic properties using vitriol

This process allows you to determine which stainless steel is magnetic and which is not corrosion resistant. It is almost impossible to determine the characteristics of a food alloy on your own.

Magnetic properties can also be checked using a regular magnet. However, it does not give an accurate result.

That is why it is recommended to purchase products from reputable manufacturers.

Portable metal analyzer

In conclusion, we note that magnetic properties do not in any way reduce the corrosion resistance of the surface. That is why such alloys are characterized by a wide range of applications.

Source: https://morflot.su/kakaja-nerzhavejka-magnititsja-i-pochemu-kakaja/

Food grade stainless steel: properties of cookware and types of steel grades

At the beginning of the twentieth century, a unique property of steel with a high chromium content was discovered - the ability to resist corrosion. This discovery led to revolutionary changes in industry. Any corrosion-resistant steel began to be called stainless. Almost immediately, experiments began on the use of such steels in the food industry. However, food grade stainless steel gained real popularity only towards the end of the twentieth century.

Features of metal utensils

Important parameters for any cookware are ease of use and safety in contact with food. Historically, the vast majority of cooking containers were made of aluminum and enameled steel. Stainless steel kitchen items began to spread much later.

Enameled products

Most steels are not safe in contact with food. As a result of contact with food, steel ions can form salts that are extremely harmful to the human body. To protect against such contact, the technology of coating steel with enamel was invented.

The use of enamel makes it possible to achieve a perfectly smooth surface that prevents the growth of bacteria. In such dishes you can not only cook, but also store food. However, all the benefits are valid only for a new coating that has been in use for a short time.

The enamel is subject to abrasion and is prone to cracks and chips. When washing such dishes, do not use abrasive cleaners or metal brushes. Cracks can also form due to sudden temperature changes. In case of any damage to the coating, the dishes must be immediately disposed of, since the steel used as the base of the product does not have special food characteristics.

Food grade aluminum

Aluminum pots and pans were very widespread in our country and were used without applying any special coatings to prevent metal contact with food. Recently, you can often hear about the dangers of using aluminum cookware. This issue has not yet been sufficiently studied, so scientists have not yet come to a consensus.

The only thing that can be stated unequivocally is that contact with aluminum of acidic products is strictly prohibited. It is also prohibited to store prepared foods in such containers; after cooking, you must immediately transfer the food to a suitable container.

Safety steel

The spread of stainless steel cookware is considered a revolution in the development of kitchen utensils. It is considered the most durable and easy to use. Initially, such steel began to be considered the safest when in contact with food. However, this issue deserves a separate discussion, because not all alloys used are the same in their properties. Much depends on the brand of food grade stainless steel and its chemical composition.

Advantages of stainless steel

Stainless steel has earned its popularity due to the combination of a number of properties that simplify the cooking process and make food safe. Many other advantages also played an important role in the popularization of stainless steel. Modern housewives value stainless cookware for the following qualities:

• Durability. With careful use, a stainless steel container can last up to a hundred years or more. Even scratches on the surface of a worn product will not be a contraindication for use.
• Strength. High strength characteristics are characteristic of any steel products. High-quality stainless steel cookware is thick enough to resist warping and scratches.
• Hygiene. Corrosion-resistant steel is protected from oxidation. Bacteria do not accumulate on the surface.
• Attractive appearance. A high-quality processed product retains excellent decorative properties for a long time. The ability to use electric polishing for processing such steels helps to create a perfectly smooth surface.
• Easy to care for. Contaminants from the surface of the material are easily removed. Stainless steel has no contraindications to the use of any detergents and tolerates cleaning well in the dishwasher.

Security questions

Most people consider stainless steel to be absolutely harmless. However, discussions on the safety of its use continue. Many grades of corrosion-resistant steel contain nickel. It is considered to be a strong allergen. Some scientists talk about the carcinogenic properties of this element.

Proponents of the theory that food steels are harmful do not recommend cooking excessively spicy foods and vegetable dishes in such dishes. This is explained by the fact that vegetable juice during cooking can react with ionized forms of alloy particles. As a result of such reactions, nickel salts can be formed, which are especially harmful to the human body.

Based on such data, stainless steels with a minimum nickel content are generally considered harmless. A special marking is being introduced indicating the absence of nickel. The cost of such cookware is usually higher than other stainless steel products.

The lack of detailed studies of the influence of the chemical composition of corrosion-resistant steel on the safety of use in the food industry and the significant increase in prices for certain types of products give reason to assume that the spread of such doubts is just a successful marketing ploy by some manufacturers.

Stainless steel products usually cost an order of magnitude more than products made from other metals. Against this background, there is a great temptation to purchase cheaper cookware made in Asian countries. Usually the origin of such products is questionable.

If the cost reduction is achieved by reducing the mass of the finished product, this will not affect the safety of its operation. Only strength and service life will be affected. It is much more dangerous to use dubious steel, the chemical composition of which is unknown.

Undesirable impurities that are in the material easily pass into food when heated. You can recognize the use of such low-quality material by the metallic taste of cooked food.

It is felt especially strongly if you simply boil water in this container.

Security is not something you can skimp on. It is better to refrain from purchasing products of unknown origin, especially if there are clear doubts about their quality.

Types of alloys and best models

For a long time, among all food steels, the leading position in the production of tableware in our country was occupied by 12Х18Н10Т. It is with this alloy that the concept of food grade stainless steel is firmly connected. However, there are other materials that are widely used in the manufacture of tableware. This raises the question of which corrosion-resistant steels are suitable for food use.

Food and technical steel

GOST standards do not define the concept of food grade stainless steel. Experts cannot give a definite answer as to which specific brands can be used in the food industry. Therefore, the question of how food-grade stainless steel differs from technical stainless steel remains unanswered.

Manufacturers believe that any stainless steel can be used in food production and home cooking. The only question is the economic feasibility of dishes from certain brands.

Choice if not marked

Many people wonder how to choose quality products. If the cookware is marked with an indication of the steel used, there should be no questions when purchasing. Difficulties begin in situations where there is no marking on the product, and the seller claims that the steel is stainless. There are not many ways to find out what material is in front of us, that is, to distinguish stainless steel.

The simplest option for identifying stainless steel has long been known. It is based on the lack of magnetic properties in corrosion-resistant steels of many grades. To check the dishes, it is enough to have a regular magnet, with the help of which the test is carried out. If the product is not magnetic, it is truly stainless steel. This method is suitable for many domestic products and a number of imported ones.

Some stainless steels have magnetic properties, so using this testing method will be useless. Unfortunately, there is no other way to check the material when purchasing. However, at home, you can expose the dishes to a two percent vinegar solution. If there is no reaction, it is stainless steel. If the color of the metal has changed, there is a serious reason to think about the safety of using such a product.

Rules of care

Each piece of kitchen utensil needs proper use and care. This way you can achieve the longest service life of the product and maintain its attractive appearance. Here are the basic rules for using stainless cookware:

• It is recommended to wash products immediately after use.
• Wash dishes with warm water and liquid detergents.
• It is allowed to use sponges of low and medium hardness for washing.
• Items can be washed in the dishwasher if marked accordingly. If it is not there, you will have to make the decision yourself. Typically, any stainless steel cookware can withstand machine washing well.
• When cleaning, it is not allowed to use hard brushes or compounds containing abrasive substances.
• It is strictly forbidden to use products containing chlorine and ammonia for cleaning.
• It is not recommended to store cooked food in stainless steel containers for a long time.
• Do not preheat empty containers to high temperatures to avoid the appearance of tarnish. If they appear, you can eliminate the defect with vinegar or lemon juice.
• It is not recommended to salt cold water to avoid salt settling on the walls of the dish. It is better to add salt while boiling and stirring at the same time.
• Do not use abrasives to remove burnt-on stains. You can fill the container with warm salt water, leave it for several hours, and then wash it in the usual way.
• A glossy surface that has become cloudy and scratched during use can be restored to its original condition using special polishing products.

Dishes and other kitchen utensils made from food-grade stainless steel have long earned popularity. They combine durability and safety of use. Items made of high-quality stainless steel, with proper use and care, will last for many decades and make the cooking process convenient and enjoyable.

Source: https://obrabotkametalla.info/splavy/vidy-pishhevoj-nerzhavejki