How can 304 stainless steel and 201 stainless steel be distinguished by magnet?
Magnets can basically distinguish between the two types of stainless steel. Because 201 stainless steel (chromium, stainless steel) in any state can be attracted by magnets; 304 stainless steel (chromium nickel stainless steel) in the annealing state is generally non-magnetic, and after cold processing, some will be magnetic. However, the manganese steel with high manganese content is non-magnetic; the magnetic properties of chromium, nickel and nitrogen stainless steel are more complex: some are non-magnetic, some are magnetic, some are without magnetism and the surface is magnetic. Therefore, although the basic difference between magnet chromium and chromium nickel stainless steel, but can not distinguish between some special properties, but not distinguish the concrete steel.
After pickling of stainless steel, surface color silver finish: chromium nickel stainless steel color white jade is white; chromium stainless steel slightly weak light Ze; CrMnN Stainless steel and chromium nickel stainless steel similar color is slightly lighter. The surface color: stainless steel pickling chrome nickel steel is brown and white, brown and black chromium, chromium manganese nitrogen is black (the three color refers to the oxidation of the heavier color). Cold rolled unannealed chromium nickel stainless steel, silver reflective surface.
The steel of the oxide layer was removed, put a drop of water, rub rub after copper sulfate, such as discoloration, usually stainless steel; such as purple red, nonmagnetic high manganese steel, magnetic for ordinary steel or low-alloy steel.
