24 July 2021 Hardware Tool Steel Sheet
SKS31 Hardware Tool Steel Sheet
SKS31 tool steel is a Japanese standard alloy tool steel with high hardenability. Because tungsten forms carbides in SKS31 tool steel, this steel has more excess carbides and higher hardness and wear resistance than chromium steel and 9SiCr steel after quenching and low temperature tempering. In addition, tungsten also helps to preserve the fine grains, so that the steel obtains better toughness. Therefore, the cutting tool made of SKS31 tool steel has less chipping phenomenon and can better maintain the shape and size of the blade. However, steel is more sensitive to the formation of carbide nets. The existence of this kind of nets will cause the tool blades to peel off, thereby shortening the service life of the tools. Therefore, steel with carbide nets must be carried out according to its severity. Forging and normalizing. This kind of steel is used to make tools whose cutting edge does not heat up sharply during work and measuring tools and cutting tools that require no deformation during quenching, such as production knives, long taps, long reamers, special milling cutters, dies and other types of special purpose Tools, and cutting tools for soft non-metallic materials.
Chemical Composition:
Follow Japanese Standard (JIS G4404) w/%
- Carbon C: 0.90～1.05
- Silicon Si: ≤0.40
- Manganese Mn: 0.80～1.10
- Sulfur S: ≤0.03
- Phosphorus P: ≤0.03
- Chromium Cr: 0.90～1.20
- Nickel Ni: ≤0.25
- Copper Cu: ≤0.30
- Tungsten W: 1.20～1.60
Equivalent Grade:
China GB/YB standard grade: CrWMn
China Taiwan CNS standard grade: SKS31
Japanese JIS standard grade: SKS31
South Korea KS standard grade: STS31
International Organization for Standardization (ISO) standard grade: 105WCr1
German DIN standard grade: 105WC16/1. 2419
French NF standard Grade: 2212f90MCW5
Russian r0CT standard grade: XFl
Pre-heat treatment of SKS31 steel:
- Annealing heating and holding time is 1~2h after all the charge is heated to the annealing temperature, cooling; isothermal holding is 3~4h;
- High temperature tempering is used to eliminate cold deformation and work hardening (such as recrystallization annealing) ; Eliminate the internal stress of cutting before heat treatment. For parts with too low hardness after heat treatment, high temperature tempering is also performed before secondary quenching. The holding time is 2~3h after all the charge is heated to temperature;
- Normalizing is used to refine the grains of overheated steel and eliminate carbides. Net;
- When the annealing hardness HB of the steel is lower than 183, the quenching and tempering treatment is used to improve the surface finish of the cutting process.