铸件在凝固冷却过程中,因温度下降而产生收缩和发生相变,如收缩和相变受到阻碍,便会在铸件中产生铸造应力。铸造应力按其形成原因可分为热应力、相变应力和机械阻碍应力3种。其中热应力是铸件内残余应力的主要部分。由于残余应力的存在,致使铸件内部处于不平衡状态。这样会使工件由于应力作用产生变形大、裂纹 Casting in the solidification cooling process, due to the temperature drop and the resulting contraction and phase change, such as shrinkage and phase change are hindered, it will produce castings casting stress. Casting stress according to their formation can be divided into thermal stress, phase transition stress and mechanical obstruction stress 3 kinds. Thermal stress is the main part of the residual stress in the casting. Due to the existence of residual stress, resulting in the casting is in an unbalanced state. This will make the workpiece deformation due to stress, cracks