Stainless steel is a kind of high-alloy steel that can resist corrosion in air or chemically corrosive medium. It has beautiful surface and good corrosion resistance. It does not need to undergo surface treatment such as color plating, but it exerts the inherent surface properties of stainless steel. It is used in A type of multifaceted steel.
Nowadays, stainless steel products have been widely used in industry and life. So how to distinguish the authenticity of stainless steel? Below, the British editor will take you to understand:
1. Chemical qualitative method
The chemical qualitative method is an identification method to identify whether the magnetic stainless steel contains nickel. The method is to dissolve a small piece of stainless steel in aqua regia, dilute the acid solution with clean water, add ammonia water to neutralize it, and then gently inject the nickel reagent. If there is a red velvet substance floating on the liquid surface, it means that the stainless steel contains nickel; if there is no red velvet substance, it means that there is no nickel in the stainless steel.
2. Nitric acid
A notable feature of stainless steel is its inherent corrosion resistance to concentrated and dilute nitric acid. We can use nitric acid to drip onto stainless steel products, which can be clearly distinguished, but we need to pay attention to the fact that high-carbon 420 and 440 steels are slightly corroded during the nitric acid point test, and non-ferrous metals will immediately meet concentrated nitric acid. corroded.
3. Copper sulfate point test
Remove the oxide layer on the steel, put a drop of water, wipe it with copper sulfate, if it does not change color after rubbing, it is generally stainless steel; alloy steel.
4. Color
The surface color of acid-washed stainless steel: chrome-nickel stainless steel is silvery white jade color; chrome stainless steel is grayish white and glossy; the color of chrome-manganese-nitrogen stainless steel is similar to that of chrome-nickel stainless steel and slightly lighter. The surface color of unpickled stainless steel: chrome-nickel steel is brown-white, chrome-steel is brown-black, and chrome-manganese-nitrogen is black. Cold-rolled unannealed chrome-nickel stainless steel with silver-white reflective surface.
Post time: Oct-12-2022