202 stainless steel
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What type of steel is 202 stainless steel according to national standards?
It is equivalent to 1Cr18Mn8Ni5N in national standards; in the 2007 version of these standards, it is designated as 12Cr18Mn9Ni5N. However, 202 grades that meet national standards are hardly available on the market; their Ni content is relatively low, usually around 3.5. For specific specifications, refer to Guangzhou Lianzhong’s L4 grade.
201/202 must be what is commonly referred to as stainless steel, right? I soak it in a 5% saltwater solution here, and after 48 hours, slight rusting begins~~~
201 and 202 are not what is commonly referred to as stainless steel; both of these steel grades are austenitic stainless steels that have no magnetism. Their appearance is similar to that of 304, which is why unscrupulous sellers use them to pass off as 304. The term \"stainless iron\" generally refers to ferritic and martensitic stainless steels in the 400 series, but it is a serious mistake to assume that such materials have inferior properties compared to stainless steels; in fact, many 400 series stainless steels exhibit better performance than 304 stainless steel. The usage rate of 400 series stainless steel abroad is very high.
There are many cases in the market where 200-series stainless steel is used to pass off as 300-series stainless steel; our company experienced one such incident in one of its diesel hydrogenation units. Just a few days after the operation of the flow meter for preventing surge in the circulator, weld cracks appeared in the pressure tapping pipe, resulting in a shutdown. The anti-surge flow meter should be made of 304 material; however, spectral analysis revealed the presence of manganese, and the hardness of the welds was 280 HB. It is clear that the flow meter manufacturer used the wrong material, as there was insufficient quality control during the material procurement process. Later, when I reviewed the literature, I found that many similar refineries from that period encountered this problem.