Stainless steel Knowledge

21.During the production of stainless steel, whether during intermediate annealing or before annealing of finished products, degreasing treatment must be carried out first to remove the grease attached to the surface of the strip steel.

22. The surface of stainless steel plate BA needs to be completed through a special production line, which mainly conducts annealing treatment through protective gas H2+N2.

23.The polishing process methods for stainless steel plates mainly include mechanical polishing, chemical polishing, and electrolytic polishing.

24.After a certain amount of cold deformation, the strength of austenitic stainless steel is greatly improved. In addition to the hardening effect, the strengthening reason is also superimposed on deformation induced martensitic transformation.

25.According to the different chromium content in steel, ferritic stainless steel can be divided into three types: low chromium type, medium chromium type, and high chromium type.

26. Molybdenum is an important element in ferritic stainless steel, second only to chromium, with a pitting resistance equal to three times that of chromium.

27. Ferritic stainless steel is magnetic and can be used as corrosion resistant soft magnetic materials, such as electromagnetic valves, etc.

28.Adding nickel to ferritic stainless steel reduces the brittle transition temperature and improves toughness.

29.Adding copper to ferritic stainless steel mainly improves corrosion resistance and formability, but it increases the stress corrosion sensitivity of steel, which is more harmful than nickel.

30.ompared to 300 series stainless steel, 400 series stainless steel is more sensitive to adhesion during hot rolling due to its low tensile strength at high temperatures.

31.Duplex stainless steel refers to stainless steel in which austenite and ferrite coexist in a ratio close to 1:1.

32. Duplex stainless steel has high strength, good corrosion resistance, and good weldability

Duplex stainless steel is generally referred to as the perfect combination of low cost and high performance.

34. Duplex stainless steel generally contains low nickel, which is conducive to avoiding price risks caused by nickel price fluctuations.

35.In addition to having a medium level of corrosion resistance, general martensitic stainless steel can also be quenched to obtain martensitic structure with high strength and wear resistance to meet usage requirements, and is widely used in cutting tools, steam turbine blades, bearings, valves, structural parts, and wear parts.

36.According to the difference in alloy elements in steel, martensitic stainless steel can be divided into two types: martensitic chromium stainless steel and martensitic nickel chromium stainless steel.

37.In martensitic stainless steel, with a given chromium content, as the carbon content in the steel increases, the hardness after quenching increases, the strength of the steel increases, and the plasticity decreases.

38. Heat Treatment Process - Quenching, tempering, and aging treatment are necessary processes for martensitic stainless steel to achieve target mechanical properties, and also affect the corrosion resistance of martensitic stainless steel.

39. The main reason why copper containing antibacterial stainless steel has antibacterial function is that it precipitates on the surface of the stainless steel（ ε- Cu phase).

Stainless steel pipes are mainly used in boiler, petrochemical, chemical, oil and gas exploration, pressure vessels, non ferrous metallurgy, clean energy, transportation, nuclear power, and other fields.

41. Stainless steel precision strips are widely used in aerospace, automotive parts, electronic products, medical devices, IT, and other fields