40Cr钢材
40Cr钢材是机械制造业使用最广泛的钢之一。调质处理后具有良好的综合力学性能,良好的低温冲击韧性和低的缺口敏感性。钢的淬透性良好,水淬时可淬透到Ф28~60mm,油淬时可淬透到Ф15~40mm。这种钢除调质处理外还适于氰化和高频淬火处理。切削性能较好,当硬度为HB174~229时,相对切削加工性为60%。该钢适于制作中型塑料模具。
40Cr钢的化学成分(GB/T3077-1999)ω/%C | Si | Mn | Cr | S | P | Ni | Cu |
0.37~0.45 | 0.17~0.37 | 0.50~0.80 | 0.80~1.10 | ≤0.030 | ≤0.030 | ≤0.25 | ≤0.030 |
物理性能
40Cr钢的化学成分示于表4-8-2~4-8-5,其密度为7.82t/m3。
表4-8-2 40Cr钢的临界温度
临界点 | Ac1 | Ac3 | Ms | 备注 |
温度(近似值)/℃ | 780 770 | 840 805 | 350 328 | 1 2 |
1 用钢成分(%):0.38C,0.30Si,0.66Mn,0.95Cr,0.18Ni,0.016P,0.028S;
2 用钢成分(%):0.42C,0.29Si,0.69Mn,0.87Cr,0.14Ni,0.010P,0.013S。
表4-8-3 40Cr钢的弹性模量和切变模量
弹性模量E(20℃) | /MPa | 200000~211700 |
切变模量G(20℃) | 80800 |
表4-8-4 40Cr钢的线(膨)胀系数
温度/℃ | 20~200 | 20~300 | 20~400 | 20~500 | 20~600 | 20~700 | 备注 |
线(膨)胀系数/C-1 | (11.9~12.0) ×10-6 | (13.3~13.4)×10-6 | (14.3~14.4)×10-6 | (15.0~15.1)×10-6 | (15.3~15.4)×10-6 | (15.4~15.5)×10-6 | 1 2 |
1 用钢成分(%):0.37C,0.30Si,0.66Mn,0.95Cr,0.18Ni,0.016P,0.028S;
2 用钢成分(%):0.42C,0.29Si,0.69Mn,0.87Cr,0.14Ni,0.010P,0.013S。
表4-8-5 40Cr钢的热导率
温度/℃ | 100 | 200 | 300 | 400 | 500 | 600 |
热导率λ/W·(m·K)-1 | 32.6 | 30.9 | 29.3 | 28.0 | 26.7 | 25.5 |
40Cr钢的热加工工艺示于表4-8-6
表4-8-6 40Cr钢的热加工工艺
加热温度/℃ | 开始温度/℃ | 终止温度/℃ | 冷却方法/℃ |
<1200 | 1100~1150 | >800 | 大于60mm缓冷 |