Common stainless steel grades and properties

1. 304 stainless steel. It is one of the most widely used austenitic stainless steels with a large amount of applications. It is suitable for manufacturing deep drawing parts, pipes, vessels, structural parts, various instrument bodies, etc. it can also manufacture non-magnetic and low-temperature equipment and parts.

2. 304L stainless steel. The sensitized intergranular corrosion resistance of ultra-low carbon austenitic stainless steel is significantly better than that of 304 stainless steel. Except for the slightly lower strength, other properties are the same as 321 stainless steel. It is mainly used for corrosion-resistant equipment and components that need to be welded but cannot be subject to solution treatment. It can be used to manufacture various instrument bodies.

3. 304H stainless steel. The carbon content is 0.04% - 0.10%, and the high temperature performance is better than that of 304 stainless steel.

4. 316 stainless steel. By adding molybdenum, the steel has good resistance to reducing medium and pitting corrosion. Corrosion resistance is better than 304 stainless steel, mainly used for pitting corrosion resistant materials.

5. 316L stainless steel. Ultra low carbon steel, with good resistance to sensitized intergranular corrosion, is suitable for manufacturing welding parts and equipment with thick section size, such as corrosion-resistant materials in petrochemical equipment.

6. 316H stainless steel. The internal branch of 316 stainless steel has a carbon mass fraction of 0.04% - 0.10%, and its high temperature performance is better than that of 316 stainless steel.

7. 317 stainless steel. The pitting corrosion resistance and creep resistance are better than 316L stainless steel. It is used to manufacture petrochemical and organic acid corrosion resistant equipment.

8. 321 stainless steel. The addition of titanium improves the intergranular corrosion resistance and has good high temperature mechanical properties, which can be replaced by ultra-low carbon austenitic stainless steel. It is not recommended to use except for special occasions such as high temperature or hydrogen corrosion resistance.

9. 347 stainless steel. Niobium is added to improve the intergranular corrosion resistance. Its corrosion resistance in acid, alkali, salt and other corrosive media is the same as that of 321 stainless steel. It can be used as both corrosion-resistant material and heat-resistant steel. It is mainly used in thermal power and petrochemical fields, such as making vessels, pipes, heat exchangers, shafts, furnace tubes in industrial furnaces and furnace tube thermometers.

10. 904L stainless steel. The mass fraction of nickel is 24-26%, and the mass fraction of carbon is less than 0.02%. The corrosion resistance is very excellent, with good resistance to crevice corrosion and stress corrosion. It is applicable to various concentrations of sulfuric acid below 70 ℃. It also has good corrosion resistance to acetic acid of any concentration and temperature under normal pressure and the mixed acid of formic acid and acetic acid.

11. 440C stainless steel. Martensitic stainless steel has the highest hardness among hardenable stainless steel and stainless steel, with the hardness of hrc57. It is mainly used for making nozzle, bearing, valve core, valve seat, sleeve, valve rod, etc.

12. 17-4PH stainless steel. Martensitic precipitation hardening stainless steel, with the hardness of hrc44, has high strength, hardness and corrosion resistance, and cannot be used at temperatures higher than 300 ℃. It has good corrosion resistance to atmosphere and diluted acid or salt, good attenuation performance of 17-4PH, strong corrosion fatigue resistance and water drop resistance. The corrosion resistance is the same as that of 304 stainless steel and 430 stainless steel. It is used to manufacture offshore platforms, turbine blades, valve cores, valve seats, sleeves, valve stems, etc