Commonly used stainless steel grades and properties

Commonly used stainless steel grades and properties

1.904L stainless steel. Super complete austenitic stainless steel is a super austenitic stainless steel invented by the Finnish company OUTOKUMPU. Its nickel mass fraction is 24% to 26%, the carbon mass fraction is less than 0.02%, and it has excellent corrosion resistance. , has good corrosion resistance in non-oxidizing acids such as sulfuric acid, acetic acid, formic acid, and phosphoric acid, and also has good resistance to crevice corrosion and stress corrosion resistance. It is suitable for sulfuric acid of various concentrations below 70°C. It can withstand acetic acid of any concentration and temperature under normal pressure and has good corrosion resistance in mixed acids of formic acid and acetic acid. The original standard ASMESB-625 classified it as a nickel-based alloy, and the new standard classified it as stainless steel. China only has a similar grade of 015Cr19Ni26Mo5Cu2 steel, and a few European instrument manufacturers use 904L stainless steel as their key material. For example, the measuring tube of E+H's mass flow meter is made of 904L stainless steel, and the case of Rolex watches is also made of 904L stainless steel.

2. 321 stainless steel. Titanium-stabilized austenitic stainless steel, which adds titanium to improve intergranular corrosion resistance and has good high-temperature mechanical properties, can be replaced by ultra-low carbon austenitic stainless steel. Except for special occasions such as high temperature or hydrogen corrosion resistance, it is not recommended for general use.

3. 347 stainless steel. Niobium-stabilized austenitic stainless steel, adding niobium to improve intergranular corrosion resistance, the corrosion resistance in acid, alkali, salt and other corrosive media is the same as 321 stainless steel, the welding performance is good, it can be used as corrosion-resistant material and resistant material. Hot steel is mainly used in thermal power and petrochemical fields, such as making containers, pipes, heat exchangers, shafts, furnace tubes in industrial furnaces, and furnace tube thermometers.