24 July 2021 Cold Heading Steel Bar
ML40Cr Cold Heading Steel Bar
ML40Cr is cold forging steel for forming used, cold forging is used at one or more impact loads at room temperature, widely used in the production of screws, pins, nuts and other standard parts. The cold crucible process can save raw materials and reduce costs.
Moreover, cold work hardening can improve the tensile strength of the work piece and improve the performance. The steel used for cold crucible must have good cold upset performance, and the content of S and P in steel should be reduced. The surface quality of steel is strict, and high-quality carbon steel is often used. If the carbon steel content of steel is more than 0.25%, the ball annealing heat treatment should be carried out to improve the cold heading performance of the steel.
ML40Cr Chemical composition(mass fraction)(wt.%) :
| C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | B(%) | Al(%) |
| 0.38-0.45 | Max 0.30 | 0.60-0.90 | 0.035 | 0.035 | 0.90-1.20 | — | — |
Mechanical properties of ML40Cr:
| Yield Rp0.2(MPa) | Tensile Rm(MPa) | Impact KV (J) | Elongation A (%) | Reduction in cross section on fracture Z (%) | As-Heat-Treated Condition | HBW |
| 313 (≥) | 734 (≥) | 11 | 12 | 34 | Solution and Aging, Annealing, Ausaging, Q+T,etc | 333 |
Physical properties of ML40Cr:
| Property | Density kg/dm3 | Temperature T °C/F | Specific heat J / kgK | Thermal conductivity W/mK | Electric resistance µΩ·cm |
| 988 (≥) | 169 (≥) | 24 | 31 | 43 | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Temp. °C/°F | Creep strain limit (10000h) (Rp1,0) N/mm2 | Creep rupture strength (10000h) (Rp1,0) N/mm2 | - | - | - |
| 315 | 948 | 717 | - | - | - |