Household stainless steel tableware can be divided into three grades: 430, 18-8 and 18-10. 430 stainless steel, which is composed of iron + more than 12% chromium, can prevent oxidation caused by natural factors. It is called stainless steel, but it will still rust after long-term use. 18-8 is composed of iron + 18% chromium + 8% nickel, and 18-10 is composed of iron + 18% chromium + 10% nickel. Chromium is the material that makes the product rust free, while nickel is a corrosion-resistant material. The higher the content of nickel, the better the quality of the product and the more expensive the price.
Strictly speaking, products containing only chromium but no nickel belong to stainless steel, products containing both iron and nickel are stainless steel. It is very important to select stainless steel products to see the code. If there is no code printed on the products, it is generally nickel free products. Because nickel is an antimagnetic material, you can usually try it with a magnet when you buy it. Stainless steel products are the ones that can be attracted by magnets, and stainless steel products are the ones that are not attracted by magnets.
There were two kinds of stainless steel products named "201" on the market. Their composition did not meet the relevant standards of stainless steel completely, but they appeared in the market with the brand of stainless steel. On the surface, it is difficult to distinguish this product from ordinary stainless steel, and it is non-magnetic, which is easy to cause confusion among consumers. It is "Li Gui" in stainless steel, and its simple judgment method is its low price.
The real high-quality stainless steel must be one price one goods, expensive has the reason. The authenticity of stainless steel can be identified by chemical method. In 100ml distilled water, add 8g of anhydrous copper sulfate, then add 3 drops of concentrated sulfuric acid, and drop the solution on the surface of stainless steel products for 6 minutes. The surface of real stainless steel products will not change, and a layer of red substance will be produced on the surface of unqualified products.
In addition, when purchasing stainless steel products, we should also pay attention to the following two aspects: first, the color is black hair, which is likely to be stainless iron; the color is dark red, which is likely to replace nickel with manganese. 2. Touch by hand, no burr on the edge, smooth surface, no scratch, no sand hole.