Stainless steel----What's the difference between stainless steel 202 and 304
As we all know , currently on the market in the field of industrial washing machine is used more 202 series stainless steel , that we know 202 series and 304 series of the difference between it? In fact, how much difference is that the nickel content of chemical elements , which caused them huge difference in performance and price . In the current nickel price levels , low nickel content stainless steel 200 series 300 series stainless steel price is only about half of the anti-corrosion and toughness properties are far less than the 300 series stainless steel , is only applicable to kitchenware and food processing field , if used in the field of construction, medical equipment, etc. , there will be a big risk.
How to identify that our 300 series stainless steel and stainless steel 200 series of the ? This is crucial , strictly speaking , for our manufacturing and processing industries should use the 300 series stainless steel , but there are many small manufacturers are using 200 series stainless steel , which is responsible for the customer extremely manifestation , 200 series stainless steel nickel content is very low, easy to rust. So the majority of our clients in the purchase of the product is important to note what type of stainless steel used .
Identification of stainless steel plate in kind , is to steel in the unknown (No. ) of cases, depending on the product ( including the entire material , more than expected , scrap and other physical ) inherent physical and chemical properties , using simple equipment, which is used to determine the senses what kind of specific methods and stainless steel are not . It should be noted : sensory identification , can not distinguish between the specific steel ( kind of ) numbers, basically only difference chromium stainless steel , chrome-nickel stainless steel and chrome -manganese nitrogen three categories, the differential approach follows :
1. The color of a difference :
After pickling of stainless steel , surface color silver Bai Guangjie : chrome-nickel stainless steel color silver Bai Chengyu color ; chrome steel gray glossy white color slightly weak ; chromium -manganese nitrogen stainless chromium-nickel stainless steel with similar color is paler . Without pickling stainless steel surface color : chrome-nickel steel brownish white ; chrome steel brownish-black ; chrome manganese nitrogen was black, ( three color, color is the oxidation of heavier ) . Chrome-nickel stainless steel cold-rolled without annealing , silver reflective surface . In addition to stainless steel element , usually pickled white.
2. Use copper sulfate identification:
Method is to remove the oxide layer on the steel , put a drop of water , with the copper sulfate rub rub does not change, typically of stainless steel ; as to purple : a non-magnetic high manganese steel, is generally an ordinary magnetic steel or low alloy steel .
3. With magnet identification:
The basic difference between the two types of stainless steel magnet can . Because chromium stainless steel can be attracted to a magnet in any state ; chrome-nickel stainless steel in the annealed condition is generally non-magnetic after cold working , and some will be magnetic. However, high manganese steel is high manganese non-magnetic ; chrome-nickel stainless steel magnetic nitrogen situation is more complicated : some non-magnetic, and some magnetic, some non-magnetic and transverse vertical plane magnetic surface . So, to say , although the magnet can basically distinguish chromium stainless steel and chrome-nickel stainless steel , but can not correctly distinguish the special nature of some kinds of steel , but can not distinguish between the specific steel .