This method is used to identify stainless steel from carbon steel or other non-ferrous metals.
Tips: High carbon stainless steel 420 and 440 are slightly corroded after dripping nitric acid.
This method can distinguish stainless steel from ordinary carbon steel or iron.
Remove grease and impurities from the metal surface, polish a small area with a soft cloth, and then drip copper sulfate solution on the metal surface.
This method can be used to identify the authenticity of austenitic stainless steel (such as 301, 304, 316, 316L, etc.).
Tips: 304 stainless steel may be magnetic after cold working.
Test the magnetic properties of the metal, if it is magnetic, it means that the metal is not austenitic stainless steel.
Austenitic stainless steel includes:
|Euronorm (EN) number||EN designation||AISI grade||C||Cr||Mo||Ni||melting point (°C)|
|1.4305||X8CrNiS18-9 e||303||< 0.10||18||NS||9||1420|
The chemical element analysis method is to use a few grams of metal drill cuttings for chemical analysis to obtain the correct content of each chemical element in the stainless steel, which is a common method in various enterprises.
However, this method requires professional testing equipment, so it will not be described in detail.
The following identification methods are from the Internet, which is wrong, or quite inaccurate.
This statement is obviously wrong. As stated above, only austenitic stainless steels are non-magnetic.
In fact, it is difficult to distinguish with the naked eye by this method. Because not only the sparks between stainless steel and other metals are different, but the sparks between different stainless steels are also very different.