24 July 2021 Cold Heading Steel Bar
ML20MnTiB Cold Heading Steel Bar
ML20MnTiB cold heading steel is the production of 10.9 standard parts of the commonly used steel, which is characterized by a small amount of boron instead of the most alloying elements, carbon, and alloy elements content is low, the cost is reduced; hot strip can be directly drawn and cold heading processing, No pre-spheroid-zing annealing is required, saving the cost of manufacturing the fastener.
ML20MnTiB cold heading steel as one of the main materials of high strength bolts, with excellent cold deformation performance and strength and toughness, quenching deformation and cracking tendency is small, available water quenching treatment, not only heat treatment is simple, the working environment has been improved, and comprehensive mechanics Good performance, decarburization sensitivity is small, more suitable for the production of high strength bolts.
Chemical composition(mass fraction)(wt.%) of the ML20MnTiB:
| C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | B(%) | Al(%) | Ti(%) |
|---|---|---|---|---|---|---|---|---|
| 0.19-0.24 | Max 0.30 | 1.30-1.60 | 0.035 | 0.035 | — | 0.0005-0.0035 | 0.02 | 0.04-0.10 |
Mechanical properties of grade ML20MnTiB:
| Yield Rp0.2(MPa) | Tensile Rm(MPa) | Impact KV (J) | Elongation A (%) | Reduction in cross section on fracture Z (%) | As-Heat-Treated Condition | HBW |
|---|---|---|---|---|---|---|
| 464(≥) | 638 (≥) | 42 | 23 | 23 | Solution and Aging, Annealing, Ausaging, Q+T,etc | 222 |
Physical properties of grade ML20MnTiB:
| Property | Density kg/dm3 | Temperature T °C/F | Specific heat J / kgK | Thermal conductivity W/mK | Electric resistance µΩ·cm |
|---|---|---|---|---|---|
| 367 (≥) | 844 (≥) | 42 | 33 | 14 | 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 | - | - | - |
| 828 | 561 | 478 | - | - | -0 |