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针对激光熔覆修复K403镍基高温合金构件组织粗大和力学性能下降的问题,提出采用激光冲击强化技术对修复区进行表面强化。利用SEM观察不同区域微观组织,利用显微硬度、残余应力和高温拉伸强度测试研究其力学性能。结果表明,激光冲击强化细化试样表层晶粒;强化后,试样基体区和熔覆区表面硬度分别提高21%和8%,影响深度约0.8 mm;激光冲击在试样表层引入约610 MPa且均匀分布的残余压应力,影响深度层达1.2 mm,经保温处理后,应力释放约18%,但在表面仍残留较大的残余压应力;激光冲击提高了材料高温拉伸强度约15%,解决了激光熔覆修复K403镍基构件力学性能下降的问题。
Aiming at the problem of laser cladding to repair coarse structure and mechanical properties of K403 nickel base superalloy, laser shock strengthening technology is proposed to strengthen the surface of repaired area. The microstructures of different regions were observed by SEM, and their mechanical properties were studied by microhardness, residual stress and high temperature tensile strength. The results show that the laser shock strengthens the surface grain of the refined sample. After strengthening, the surface hardness increases by 21% and 8% respectively in the base region and cladding region of the sample, and the influence depth is about 0.8 mm. Laser shock introduces about 610 MPa and uniform distribution of residual compressive stress, affecting the depth of up to 1.2 mm, after heat treatment, the stress release of about 18%, but the surface still residual residual compressive stress; laser shock to improve the high temperature tensile strength of about 15 %, To solve the laser cladding K403 nickel-based structural components to reduce the mechanical properties of the problem.