H13钢制分流模低周疲劳寿命的预测方法及应用

 利用Gleeble1500热模拟试验机对H13模具钢在650-800℃温度范围，0.1-20s-1应变速率下的热压缩变形行为进行了研究，并得到了该材料在20-650℃范围内的弹性模量，建立了H13钢的有限元模型；通过高温拉伸实验和通用斜率法建立了H13钢的应变-低周疲劳寿命关系；结合有限元方法提出了一种预测H13钢制铝型材挤压模具低周疲劳寿命的方法，并在此基础上得到了工艺和结构参数对模具疲劳行为的影响规律。结果表明：疲劳应变损伤值随着挤压速度的增加以及模桥根部圆角半径的减小而增大，其中结构参数为关键影响因素。最后通过生产实际验证了该方法的可靠性。

Low Cycle Fatigue Life Prediction Method and Application of Porthole Die Made of H13 Steel

The thermal compression experiments were achieved at temperatures from 650℃ to 800℃and strain rates from0.1s-1 to 20s-1 on the Gleeble-1500 simulator to get.the flow stress behaviors of H13 steel, and the elastic modulus at temperatures from 20℃ to 650℃ were also obtained, based on which, the elastic-plastic constitutive equation was established finally. Through the high-temperature tension test and universal slope equation, the relationship of strain amplitude and low cycle fatigue life was constituted. A new method for predict the die low cycle fatigue life based on FEM was developed. The rules of the influence of design and process parameters on fatigue failure behaviors were also estimated .The results show that the strain damage value which closely related to the accuracy of design parameter rises with the increase of the extrusion speed while decreases with the augment of the bridge root’s radius. Finally, this method and results were confirmed from the industrial verification.