Stainless steel has the following characteristics that are not rust, acid, high temperature resistant, wear resistant and austenitic general non-magnetic. Stainless steel is one of the high alloys steel that our common use, such as stainless steel cutting tools, stainless steel kitchen utensils, and stainless steel building materials and so on. Stainless steel that we see everyday mostly is the 302, 304 and so on, basically the same steel grade nickel chromium stainless steel and 1-4 Cr13 chromium stainless steel. In our country, the varieties of stainless steel (steel grade) in more than 100, and its elements in the steel grade and content of different, its performance and value are also quite different. Therefore, the identification of the stainless steel must be carefully study, understand steel grade clearly. Only comprehensive test method can correctly identify, here as a stainless steel sheet manufacturers ,we will introduce sensory discrimination method
Sensory identification can't distinguish the specific steel (kind of), only difference basically chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel three categories, the identification method is as follows:
The identification of colors and luster: After acid pickling of stainless steel, the surface color is bright and clean, Chromium nickel stainless steel color silvery white jade, Chromium stainless steel color white slightly grey luster weak; the color and luster of chromium manganese nitrogen stainless steel is similar to chromium nickel stainless steel is a bit pale. Without pickling of stainless steel surface color: brown and white chrome-nickel steel, chrome steel, brown and black chromium manganese nitrogen in black. Without annealing cold-rolled stainless steel, chromium nickel surface is reflective.
With magnet for identification: magnets can basic difference between two kinds of stainless steel. Because of the chromium stainless steel in any state can be a magnet to attract; Chromium nickel stainless steel in annealing state is generally no magnetic, after cold working, some become magnetic. But the high manganese content in the high manganese steel is non-magnetic; Chromium nickel nitrogen stainless steel magnetic situation is more complicated: some nonmagnetic, some magnetic, some longitudinal surface nonmagnetic and horizontal surface magnetic. Therefore, magnet can basic difference between nickel chromium and chromium Stainless steel sheet, but can't distinguish between some special steel, more can't distinguish the specific steel grade.
With copper sulfate to identify: To remove the oxide layer on the steel, put a drop of water, with copper sulfate, brush, brush after such as, general stainless steel; If change, amaranth, nonmagnetic for high manganese steel, general for the common magnetic steel or low alloy steel.
