显微组织对工模具钢疲劳裂纹扩展速率和门坎值的影响

• 作 者: 崔崑 胡镇华 袁杰锋 张同俊 赵菊华
• 机 构: 华中理工大学,华中理工大学,华中理工大学,华中理工大学,华中理工大学,
• 出 处: 钢铁
• 发表日期: 1989年04期
• 关键词: 基体钢 显微组织 残余奥氏体 含铌 工模具钢 热处理工艺 奥氏体化温度 晶粒尺寸 回火温度 弯曲疲劳试验

用三点弯曲疲劳试验测定了M2高速钢和含铌基体钢等三种工模具材料的疲劳裂纹扩展速率da/dN和门坎值ΔK_(th),并从合金成分和热处理工艺角度分析了显微组织的影响。试验结果表明:ΔK_(th)随基体韧性的改善,残余奥氏体的增加和晶粒尺寸的增大而提高;中速区da/dN主要取决于基体韧性的好坏,较多韧性相使其延缓,较大碳化物使其加速,而对晶粒尺寸不敏感。

Three-point bending fatigue test was used to measure the fatigue crack growth rate da / dN and threshold value ΔK th (th) of three kinds of tool materials, including M2 high speed steel and niobium-containing matrix steel. The microstructure and heat treatment process were also analyzed. The impact of the organization. The results show that ΔK_ (th) increases with the improvement of matrix toughness, the increase of residual austenite and the increase of the grain size. The da / dN of medium speed zone mainly depends on the toughness of the matrix and more ductile phase Its delay, larger carbide to accelerate, but not sensitive to the grain size.