Food grade stainless steel

Food grade stainless steel - is a material resistant to oxidation, it is safe when interacting with drinking water and food, does not dissolve and does not release toxic elements into food. This also makes it practical in regular maintenance (easy to clean and wash).

When preparing, storing and transporting food products, special requirements must be observed - people's lives and health depend on them. Of particular importance are the temperature conditions, the processing and technology used, containers and packaging. Food stainless steel, biologically and toxically safe, resistant to corrosion - is ideal for the production of various equipment and containers.
When buying a specific product or any material, we should always know how safe they are and whether they meet the requirements of various standards. Quite often, in the standards for the brand manner of such stainless alloys, "food grade stainless steel" is not separately identified, and these products simply belong to the general-purpose type. There are many examples of this approach. Thus, the American standard ASTM A240 / A240M (ASTM is the American Society for Testing and Materials) stipulates the requirements for chromium-nickel corrosion-resistant steels for the manufacture of pressure vessels and for general purposes, including the food industry.
But there are a number of international standards that apply to final products. Such standards determine the chemical composition and other parameters of final products for a specific application. As an example, we can consider the standard EN 10357 (DIN 11850) "Corrosion-resistant steel pipes for the food, chemical and pharmaceutical industries". It allows the use of only the following grades for these purposes: X5CrNi18-10 (analogs: AISI 304, EN 1.4301), X2CrNi18-9 (analogs: X2CrNi19-11, AISI 304L, EN 1.4306, EN 1.4307) X2CrNiMo17-12-2 (analogs: AISI 316L, EN 1.4435).

Equipment and elements of various designs in the food industry constantly interact with an aggressive environment during production: they are washed with solutions of sulfamic acid, caustic soda, and also encounter acetic acid and fermentation products. All this requires that the material for cooking should be resistant to corrosion, not enter into chemical processes with food products and semi-finished products during processing, production, packaging and transportation. Such properties are inherent not in all stainless steel grades, but only in special alloys with a special alloying system. Items made of food stainless steel have a very attractive appearance and meet the requirements of hygiene and sanitation. Such items do not pose a toxicological hazard.

According to many consumers, there is stainless food grade and technical (non-food grade) steel. The difference lies in their different chemical composition and different technological and operational properties. Ordinary consumers believe that food grade is better, lighter and easier to grind or even polish to a mirror shine, while technical grade has a more matte surface and is much more difficult to process. But in fact, the boundary between these two varieties is very vague or does not exist at all, since stainless steel in the food sector is used to produce far more than just pots and cutlery.
Pipelines and tanks operating in aggressive environments or under the influence of high temperatures, pressure boilers, cutting tools and much more - each type of product places its own set of requirements on the source material.
Due to the content of chromium in the metal, and its mass fraction in some grades can reach as much as 27%, stainless food steel has high resistance to corrosion. Chromium ensures the formation of a protective oxide film on the metal surface, resistant to external chemical influences and rust.
And to increase the corrosion resistance of steel and its immunity to the effects of acids, salts and alkalis, nickel, copper, titanium, molybdenum and other alloying elements are introduced into its composition.

The choice of stainless steel grade for the food industry depends on the conditions of future operation and the duration of contact with finished food products and their ingredients. If the equipment is in constant interaction with water, alcohol, yeast, then it is necessary to select grades that are maximally resistant to corrosion. All steel grades for the food industry are alloyed.
The chemical composition of food stainless steel varies. This, in turn, affects its physical and mechanical properties. As written above, the main alloying component is chromium, which significantly increases the anti-corrosion properties of steel. Nickel also imparts corrosion resistance and increases strength. Titanium provides the alloy with stability when exposed to aggressive environments and resistance to intercrystalline and pitting corrosion.
According to their structure, corrosion-resistant steels are divided into:
- ferritic;
- austenitic;
- martensitic;
- duplex (austenitic-ferritic), etc.
And the more complex the metal’s composition, the more unique its performance properties.

Food grade stainless steel is valued for its many qualities. In addition to its anti-corrosion properties, one of the most significant is its resistance to bacterial and fungal waste products, which is important for the production and storage of any food products. Utensils and accessories made from it occupy a worthy place in every housewife's kitchen.
Modern, convenient and stylish pots with a thick bottom can keep heat for a long time. When used for cooking, food products retain many useful microelements. Cookware from this high-quality material is also produced for induction cookers.
Cutlery - elegant, with a good design made of stainless steel serve as a table decoration. For professional sets, austenitic stainless steel is used, containing 18-20% chromium and 8-10% nickel. Such material is completely safe and is not attracted by a magnet and is not subject to corrosion.
Martensitic stainless steel containing about 12 - 14% chromium grade AISI 420 is widely used in the production of knives (including kitchen knives). However, it does not resist corrosion very well under long-term exposure to aggressive environments.
Ferritic grade AISI 430 steel contains 16-18% chromium. It is used for cheap cutlery, although it is considered technical, like grade AISI 420.
Stainless steel is used to make durable, comfortable and reliable furniture. The most commonly used grade of stainless steel for the food industry is AISI 304. The service life of racks, tables, sinks, shelves, counters and other structures made from it is 10 years or more. Other, cheaper grades can be used, but such equipment will be less resistant to corrosion.
Kitchen equipment made of stainless steel is in great demand. Stands for combi steamers, stoves, hot tables and much more are made from such food grades.

The answer is clear - huge. In the industrial processing of meat and fish, grains and legumes, fruits and vegetables, a colossal amount of equipment is used in terms of purpose and design. And from corrosion-resistant grades of food stainless steel are produced:
- pipelines for transportation and distillation of liquids;
- coils and heat exchangers;
- filter presses and presses;
- barrels, flasks, fermentation tanks and storage tanks for milk, fermented milk products and molasses;
- steel conveyor belts and transporters;
- filter centrifuge spindles;
- oil producers and fat burners;
- vacuum crystallizers;
- dosing devices;
- separators;
- packaging and drying machines; crushers and mixers;
- dough mixing machines;
- mince mixers;
- hinged cabinets and other equipment for meat processing plants, wineries, confectionery factories, etc.

Each alloy used in the food industry must have a certificate of conformity, a quality certificate and a sanitary and hygienic conclusion. All types, grades, and categories of stainless steel, regardless of their chemical composition and processing, must meet the requirements of the food industry and, when used correctly, must not cause harm to human health and life.
Food grade stainless steel - is one of the most environmentally friendly materials. It can be used together with many other materials, such as cast iron, wood, ceramics, glass, plastic. The main thing is to choose the right grade of stainless steel.

The corrosion resistance of food grade stainless steel, like any stainless steel, is ensured by the high concentration of chromium. It is chromium that promotes the formation of an oxide protective film on the surface of the metal. The composition of food grade stainless steel must contain such chemical elements as, for example, nickel, titanium, cobalt, molybdenum. Adding such elements to the steel turns ordinary stainless steel into food grade. This combined material exhibits extremely high resistance to aggressive environments and the effects of salt solutions.

It should be noted that quickly distinguishing food grade stainless steel from non-food grade using a magnet is a mistake. There are grades of food grade stainless steel that are magnetic.