1. Stainless steel 305 and stainless steel 304 have different nickel metal content: Stainless steel 305 has higher nickel metal content than stainless steel 304, and has better aging and deep drawing performance than 304, and can be widely used in various applications.
2. Stainless steel 305 and stainless steel grades are different: 304 stainless steel corresponds to the domestic grade 1Cr18Ni12, GB/T1220-1992. 305 stainless steel corresponds to the domestic grade 10Cr18Ni9, and the standard is 06cr19ni10.
3. The scope of application of stainless steel 305 and stainless steel is different: the scope of application of stainless steel 305 is: chemical containers, mechanical equipment parts, heat-resistant equipment parts, low-temperature container parts, etc. The scope of application of stainless steel 304 is: food, chemical, atomic energy and other industrial equipment, as well as the field of decoration, household goods, cabinets and other fields.
The processing method of stainless steel 305 and stainless steel 304:
1. Solution treatment: The purpose is to fully dissolve carbides and retain them in austenite at room temperature, so as to obtain a single-phase austenite structure at room temperature, so that the steel has the highest corrosion resistance. The heating temperature of solution treatment is generally higher, between 1050-1100℃, and adjusted appropriately according to the carbon content. Quenching and heating should be carried out after preheating, and the holding time during solution treatment (quenching heating) should be long.
2. Stress relief annealing: In order to eliminate the residual stress after cold working, the treatment is carried out at a lower temperature. It is generally heated to 250-425°C, and 300-350°C is often used. For steel that does not contain titanium or niobium, it should not exceed 450°C to avoid precipitation of chromium carbide and cause intergranular corrosion. In order to eliminate the residual stress after welding and eliminate the sensitivity of steel to stress corrosion, the treatment is generally carried out at a higher temperature. The heating temperature is generally not lower than 850°C.
3. Stabilization treatment: In order to prevent the austenitic stainless steel of titanium and niobium from being welded or solution treated, due to the decrease of TiC and NbC, the resistance to intergranular corrosion should be reduced, and the stainless steel needs to be heated to a certain temperature (the The temperature makes the chromium carbides completely dissolve in austenite, while TiC and NbC only partially dissolve) and then slowly cool down.
Post time: Aug-13-2021