对补焊修复的12Cr12Mo马氏体耐热钢燃气轮机叶片表面进行陶瓷丸+玻璃丸的复合喷丸处理,研究了复合喷丸对叶片表层不同位置处残余应力、显微组织以及硬度的影响。结果表明:复合喷丸后叶片表面各区域均引入较高水平的残余压应力场,其中补焊区残余应力的变化最明显,引入的残余压应力最大,由复合喷丸前的35～224 MPa范围拉应力变为-937～-884 MPa范围压应力;复合喷丸后,叶片表层的X射线衍射半高宽随距表面距离的增加而减小,补焊区表层的X射线衍射半高宽均高于热影响区和基体,说明随距表面距离的增加,组织变形程度减小,且补焊区组织形变最大,组织最细小;叶片表层的硬度随距表面距离的增加而降低,补焊区的表面硬度为621 HV,高于热影响区的482 HV和基体的431 HV。

The surface of 12Cr12Mo martensitic heat-resistant steel gas turbine blade repaired by repair welding was treated by ceramic bead+glass bead composite shot peening. The effects of composite shot peening on residual stress, microstructure and hardness at different positions of blade surface were studied. The results show that a high level of residual compressive stress field was introduced into all areas of the blade surface after composite shot peening; the change of residual stress in the repair welding area was the most obvious, and the residual compressive stress was the largest, which changed from the tensile stress in the range of 35-224 MPa before composite shot peening to the compressive stress in the range of -937——884 MPa. After composite shot peening, the X-ray diffraction half-height width of blade surface decreased with increasing distance from the surface, and the half-height width of X-ray diffraction of repair welding area surface was higher than those of heat affected zone and substrate, indicating that the degree of microstructure deformation decreased with increasing distance from the surface, and the microstructure deformation in repair welding area was the largest, and the microstructure was the finest. The hardness of the blade surface decreased with increasing distance from the surface, and the surface hardness of repair welding area was 621 HV, which was higher than 482 HV of heat affected zone and 431 HV of substrate.