Cr12模具钢表面脆性开裂敏感性的研究

Study on Surface Brittle Cracking Sensitivity of Cr12 Die Steel

用维氏硬度压痕法测量了不同热处理工艺处理后的Cr1 2模具钢的表面脆性开裂敏感性 ,并结合材料力学性能探讨了Cr1 2模具钢热处理工艺与脆性开裂敏感性的关系。试验结果表明 ,Cr1 2模具钢的表面开裂敏感性与材料的硬度、强度、残留奥氏体量和冲击韧度有关。经 1 0 0 0℃、1 0 30℃淬火后冷处理并 2 0 0℃回火的 ,其表面脆性开裂抗力小于在 960℃、1 0 60℃和1 1 0 0℃淬火后冷处理并 2 0 0℃回火的 ,并且呈现表面穿晶裂纹或表面沿晶裂纹。说明了维氏硬度压痕法是一种测定表面开裂敏感性简便易行的方法。

Surface brittle cracking sensitivity of Cr12 die steel after different heat treating processes were determined by the Vicker′s hardness method.The relationships among the heat treatment processes,mechanical properties and brittle cracking sensitivity of this steel were studied.The experiment results show that surface brittle cracking sensitivity of the steel was related to its hardness,strength,the amount of retained austenite and impact toughness.The resistance of surface brittle cracking of Cr12 die steel quenched at 1000℃ or 1030℃ was smaller than that quenched at 960℃ or 1060℃ or 1100℃,and also appeared transgranular or intergranular fracture on the surface.This test shows that it is a simple and non-destructive method to determine surface brittle cracking sensitivity by Vicker′s hardness method.