Knowledge of stainless steel
Medical stainless steel refers to the use of (18-10), that is, +18% chromium + 10% nickel to make it more durable and corrosion resistant. Still leaks metal ions (close to the warning line), generally harmless but should be avoided by those with nickel allergies. [1] This stainless steel is called 18-10 stainless steel. Due to its durable and safe nature, it is mainly used in the manufacture of medical equipment and the manufacture of tableware.
The general composition of stainless steel is a combination of elements such as iron, chromium and carbon.
1.2 series: marsite + manganese alloy, 3 series: austenite + nickel alloy, 4 series: ferrite + carbon alloy
Household stainless steel can be divided into 4 and 3 series, 430 (18-0), 304 (18-8), 316 (18-10) three grades. The number in front of the code represents the chromium content, and the number after it represents the nickel content.
2.430 stainless steel (18-0): iron + 18% chromium without nickel, can prevent oxidation caused by natural factors, called stainless steel, the code name of jis is 430, so it is also called 430 stainless steel. Unable to resist oxidation caused by chemicals in the air, 430 stainless steel will still oxidize (rust) due to unnatural factors after it is not used for a period of time. 4 series belongs to carbon-containing stainless steel, the hardness is higher than 2 series and 3 series, the corrosion resistance is lower than 3 series, the processing is difficult, and it is easy to break when stretched.
3.304 stainless steel (18-8): 18/8 stainless steel. Products such as: corrosion-resistant containers, tableware, furniture, railings, medical equipment. The standard composition is 18 % chromium plus 8 % nickel. It is a stainless steel that is non-magnetic and cannot be changed by heat treatment. The GB grade is 06Cr19Ni10. [2]
4.316 stainless steel: 316 stainless steel has excellent corrosion resistance, atmospheric corrosion resistance and high temperature strength due to the addition of molybdenum, and can be used under harsh conditions; excellent work hardening (non-magnetic). [2] Mainly used in the food industry, watch accessories, pharmaceutical industry and surgical equipment, adding molybdenum to obtain a special anti-corrosion structure. Because of its better resistance to chloride corrosion than 304, it is also used as "marine steel". SS316 is usually used in nuclear fuel recovery units. [2]
The above are non-toxic stainless steel, or credit-grade stainless steel that meets the standard. The easiest way to distinguish is: use a magnet to attract the bottom, the one that can be attracted is 430, and the one that cannot be attracted or the magnetism is weak is 304. However, most of the 304 pots have a 420 magnetic conductive layer on the outer layer, which is magnetic, so the magnet detection is not accurate. Therefore, the most accurate way is to suck the bottom, and the most accurate detection is to use N8 stainless steel potion.
201 (nickel content 2%, phosphorus and manganese, moderate precipitation), with certain magnetic properties.
202 (nickel content 4%, phosphorus and manganese, slight precipitation), almost no magnetic properties. [3]
Foshan Keke Jewelry Co., Ltd. is a professional manufacturer of stainless steel and medical steel jewelry. It can provide stainless steel jewelry catalogs for free. Customers can choose the products in the catalog or have their own designs. We help customers realize the design and make products!
