冲击载荷作用下的锻锤热力耦合分析

Thermo-mechanical coupling analysis of forging hammer under impact load

以用于径向锻造且由基体、过渡层、耐磨层三部分构成的材料复合锻锤为研究对象,分析瞬态热流、循环冲击载荷和热载荷导致的锻锤裂纹失效问题。通过构建热力耦合模型确定锻锤的裂纹危险区域,探讨冲击载荷、温度场与变形的传递关系,进而得到锻锤分别在冲击载荷、温度场和热力耦合作用下的应力和变形分布特征。研究结果表明,锻锤温度场分布不均匀,热影响区主要位于耐磨层工作面,温度随工作面纵向深度的增加而降低;耐磨层的机械应力远大于热应力,是产生疲劳裂纹的主要原因;锻锤变形主要是机械应力和热应力共同作用的结果,最大变形区域位于耐磨层工作面靠近预变形区一侧。仿真分析结果与锻锤实际失效情形一致,可为锻锤的优化设计提供参考。

A composite forging hammer for radial forging process,consisting of substrate,transition layer and wear-resistant layer,was studied.The hammer’s crack failures caused by transient thermal flux,cyclic impact load and thermal load were analyzed.A thermo-mechanical coupling model was established to determine the crack hazard area in the forging hammer,and the transfer relationships between impact load,temperature field and deformation were discussed.Then the stress and deformation distribution characteristics of the hammer under impact load,temperature field and coupled thermo-mechanical field were obtained.The results show that the temperature field in the forging hammer is not uniform,the heat affected zone is mainly located on the working surface of the wear-resistant layer,and the temperature drops with the increasing longitudinal depth of the working surface.The mechanical stress of the wear-resistant layer is much greater than its thermal stress and becomes the main cause of fatigue cracks.Deformations of the forging hammer are mainly due to the combined action of mechanical stress and thermal stress,and the maximum deformation area is located on the working surface of the wear-resistant layer and close to the pre-deformation region.The simulation analysis results are consistent with the actual failure cases and can serve as reference for the optimal design of forging hammers.