What is the difference between food grade 304 stainless steel and ordinary stainless steel?
Food grade stainless steel refers to stainless steel materials that comply with the National Standard of the People's Republic of China / Hygienic Standard for Stainless Steel Utensil Containers GB 9684-88, and its lead and chromium content is much lower than that of general stainless steel.
Food grade stainless steel refers to the part of food machinery that comes into contact with food, which must meet certain food safety requirements. Because the food production process uses many acids and alkalis, and stainless steel contains chromium, unqualified stainless steel will dissolve chromium at various prices and is toxic; and it is required to limit the content of various alloy impurities such as lead and cadmium.
The difference between food grade stainless steel and 304 stainless steel
When the heavy metal migrated by stainless steel products in use exceeds the limit, it may endanger human health.
Therefore, the production of stainless steel cookware needs to find a balance between corrosion prevention and safety. If the content of nickel and chromium is high, the anti-corrosion function will be enhanced, but the amount of nickel and chromium precipitation will also increase, which means that the safety risks will increase.
Because of this, the National Food Safety Standard for Stainless Steel Products (GB9684-2011) has set strict guidelines for the precipitation of various heavy metals such as chromium, cadmium, nickel, and lead in cookware.
Why does the national standard not stipulate the migration limit of manganese?
One reason is that with the increase of the manganese content in stainless steel, there is a loss of functions such as corrosion resistance and non-rusting of the cooker. Once the manganese content reaches a certain value, this product cannot be used as a cooker or cannot be called a stainless steel cooker. Already. But even such high levels of manganese generally have no effect on health.
Therefore, although the national food safety standard does not stipulate the content of manganese, it is clearly stated that the main part of the food container must be made of stainless steel that meets the national standard.
Food grade stainless steel is stainless steel that meets GB9684 standard
Food grade stainless steel, also called "GB9864 stainless steel", is the stainless steel material that passed the GB 9684-2011 stipulated in the "National Standard of the People's Republic of China / Hygienic Standard for Stainless Steel Food Containers". This stainless steel has a lower "lead" content than ordinary stainless steel. The corrosion resistance of the product has also increased. The requirements are: lead (calculated as Pb), mg / L 4% acetic acid soaking solution ≤ 1.0 1.0. Chromium (calculated as Cr), mg / L 4% acetic acid soaking solution Medium ≤ 0.5. Nickel (calculated as Ni), mg / L 4% acetic acid soaking solution ≤ 3.01.0. Tin (as Sn), ≤ 0.02 0.02 in mg / L 4% acetic acid solution. Arsenic (as As), ≤ 0.04 0.04 in mg / L 4% acetic acid solution. Note: The soaking conditions are boiling for 30min, and then at room temperature for 24h.
304 stainless steel is a very common stainless steel, also called 18-8 stainless steel in the industry. Its corrosion resistance is better than 430 stainless iron, corrosion resistance and high temperature resistance, good processing performance, so it is widely used in industry and furniture decoration industry and food and medical industry, such as: some high-end stainless steel tableware, bathroom kitchen appliances.
304 is a versatile stainless steel, which is widely used to make equipment and parts that require good comprehensive performance (corrosion resistance and formability).
In order to maintain the inherent corrosion resistance of stainless steel, steel must contain more than 17% chromium and more than 8% nickel.
Generally, 304 stainless steel is not food grade, and specially processed is food grade.