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Is it true that stainless steel tubes can be magnetized in any state?

Is it true that stainless steel tubes can be magnetized in any state?

Time:2022-03-18 Source:China Wuxi JiaNuo Special Steel Co.


Physical identification, is to be in the case of unknown steel (No.), according to the goods (including the whole material, residues, scrap and other physical) inherent physical and chemical properties, with the help of simple apparatus, with the senses to determine whether it is stainless steel and is a specific method of which class of stainless steel. How to identify the 200 series of stainless steel, it should be noted that: sensory identification, can not be distinguished from the specific steel (species) number, only basically distinguish chromium stainless steel, chromium-nickel stainless steel and chromium-manganese-nitrogen stainless steel three categories, the identification methods are as follows.


1. Color difference: after pickling stainless steel, the surface color silvery white glossy: chrome nickel stainless steel color silvery white jade; chrome stainless steel color white slightly gray luster is weak; chrome manganese nitrogen stainless steel color and chrome nickel stainless steel similar slightly light. The surface color of stainless steel without pickling: chrome-nickel steel is brownish white; chrome steel is brownish black; chrome manganese nitrogen is black, (these three shades, refers to the oxidation of heavier shades). Cold-rolled unannealed chromium-nickel stainless steel, the surface is silvery white with reflective. Stainless steel, in addition to meta-steel, are generally white by pickling.

2. Identification with copper sulfate: the method is to remove the oxide layer on the steel, put a drop of water, rub with copper sulfate, after rubbing, such as no discoloration, generally for stainless steel; how to identify the 200 series of stainless steel, such as become purple-red: non-magnetic for high manganese steel, magnetic general for ordinary steel or low-alloy steel.

3. Identification with a magnet: a magnet can basically distinguish between two types of stainless steel. Because chromium stainless steel in any state can be attracted by magnets; chromium-nickel stainless steel in the annealed state is generally non-magnetic, after cold working, some will have magnetic. But high manganese steel with high manganese content is non-magnetic; chromium-nickel-nitrogen stainless steel magnetic situation is more complex: some non-magnetic, some magnetic, some longitudinal surface non-magnetic while the horizontal surface is magnetic. Therefore, although the magnet can basically distinguish chromium stainless steel and chromium-nickel stainless steel, but can not correctly distinguish some special properties of steel, let alone distinguish the specific steel number.