Stainless steel detection method
For the special nature of stainless steel wire mesh, we also need to adopt the following three methods for identification.
Grinding identification: The identification of the grinding is to grind the stainless steel on the grinder and observe the spark. For example, the spark is streamlined and has more dense knots, that is, high manganese or manganese nitrogen steel with higher manganese content; if there is no knot, it is chrome steel or chrome nickel stainless steel.
Annealing method identification: cold-processed chrome-nickel stainless steel, if it is magnetic, it can be taken in a small piece of fire in the fire to let it cool naturally or into water (annealing). Generally, the magnetic properties will be significantly weakened or completely disappeared after annealing. However, some chrome-nickel stainless steels, such as Cr18Ni11Si4AlTi steel and Cr21Ni5Ti steel, contain a large amount of ferrite in the steel, and a considerable part of the internal structure is ferrite. Therefore, it is magnetic even in the state of hot working.
Identification by chemical qualitative method: The chemical qualitative method is a method for identifying whether nickel is contained in a magnetic stainless steel. The method is to dissolve the small piece of stainless steel in the aqua regia, dilute the acid solution with clean water, add the ammonia water, and then gently inject the nickel reagent. If there is a red velvety material floating on the liquid surface, it means that the stainless steel contains nickel; if there is no red velvet material, it means that there is no nickel in the stainless steel (but because the nickel content in the stainless steel is low, generally only a few percent, nickel The content is not easy to reveal or determine, and it is generally necessary to use the standard sample experiment several times before it can be mastered).
The above identification methods show that the use of the sensor to identify stainless steel, not only must be a comprehensive test using several methods, and the test results can only determine a certain type of stainless steel, can not determine which kinds of alloying elements and specific content in the steel. Therefore, the method of sensory identification is currently extremely imperfect, and some may be wrong. There are still many physical phenomena, but only knowing it, but I don't know why, and it needs further discussion.
The best way to correctly distinguish stainless steel grades is to conduct in-depth investigations and research, and ask the relevant testing units to make test decisions. This is the fundamental way to correctly distinguish the type and quality of stainless steel.
PREVIOUS： How to detect if it is really stainless steel?
