24 July 2021 High Speed Steel Bar
W7Mo4Cr4V2Co5 High Speed Steel Bar
W7Mo4Cr4V2Co5 high-speed steel is a high-speed tool steel specified in the Chinese standard GB/T9943-1988 . W7Mo4Cr4V2Co5 steel is a tungsten-molybdenum series cobalt-containing high-speed tool steel. Because the mass fraction of cobalt in the steel is 4.75%~5.75%, the high-temperature hardness and hot hardness of the steel are improved, and the tool does not deform when cutting at higher temperatures, and Good abrasion resistance. The disadvantage of this steel is its poor grindability.
In order to meet the requirements of cutting tool linear speed up to 80m/min and cutting edge temperature up to 600℃, tool hardness>60HRC during the cutting process, high-speed steel is obtained by adding a large amount of W, Mo, Cr, V and other alloy elements to high-carbon steel W and Mn can improve the thermal hardness of steel. When the tempering temperature is 500 ~ 600°C, W and Mo precipitate and form Mo2C and W2C, and secondary hardening occurs. The hardness of the steel not only does not decrease, but increases. Quenching and tempering hardness 66 ~ 68HRC, bending strength 2500 ~ 3000MPa, impact absorption energy 0.23 -0.35J, hardness at 600°C 54HRC.
Chemical Composition:
| C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | Ni(％) | Cu(％) | V(％) | Mo(%) | W(%) | Co(%) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1.05～1.15 | 0.20 ~ 0.45 | 0.20 ~ 0.60 | ≤0.030 | ≤0.030 | 3.75～4.50 | ≤0.30 | ≤0.25 | 1.75 ~ 2.25 | 4.50 ~ 5.50 | 17.50 ~ 19.00 | 4.75 ~ 5.75 |
Mechanical Propoerties:
| Yield Strength Rp0.2(MPa) | Tensile Strength Rm(MPa) | Impact Energy KV(J) | Elongation at Fracture A(%) | Impact toughness value αkv (J/cm2) | Hardness |
|---|---|---|---|---|---|
| ≥ 2060(100) | ≥ 2180(110) | ≥ 108 | ≥ 10 | ≥ 98 | ≥ 66 HRC |
Equivalent Grade:
| GB | AISI/ASTM | UNS | ISO | NF | DIN | BS |
|---|---|---|---|---|---|---|
| W7Mo4Cr4V2Co5 | M41 | T11341 | HS2-9-1-8 | HS7-4-2-5 | 1.3246 | M41 |