Method one, the color of the identification: After the pickling of stainless steel, surface color, silver and white smooth: chromium nickel stainless steel color is white jade; chromium stainless steel color white slightly gray shiny weak; chromium manganese nitrogen stainless steel color and chromium nickel stainless steel is slightly lighter. The surface color of stainless steel that has not been pickled: Chrome-nickel steel is brownish white, chrome steel is brownish black, and chromium-manganese nitrogen is black (these three shades are heavily oxidized). Cold-rolled unannealed chromium-nickel stainless steel with silver-white surface.
Method two, iron stone identification: Magnet can basically distinguish between two types of stainless steel. Because the chromium stainless steel can be attracted by the magnet in any state; the chromium nickel stainless steel is generally non-magnetic in the annealed state, and after the cold working, some are magnetic. However, manganese-rich steels with higher manganese content are non-magnetic; chromium-nickel-nitrogen-based stainless steels have more complex magnetic properties: some are non-magnetic and some are magnetic, and some have a non-magnetic vertical surface and a magnetic surface.