GH742高温合金激光冲击强化和喷丸强化残余应力

Residual stresses of GH742 Superalloy induced by laser peening and shot peening

摘要:

对GH742高温合金进行激光冲击强化和喷丸强化，利用X射线应力分析仪测定强化层的残余应力，对比分析2种残余应力的差异和特征，并采用不同的退化温度进行退火，研究表面残余应力在高温下的稳定性。 结果表明，2种表面强化方法都可以在GH742高温合金表层引入残余压应力，但激光冲击强化试样比喷丸强化试样具有更深的残余压应力层和较好的稳定性，且残余压应力最大值在表面；与激光冲击强化的试样相比，喷丸强化试样的残余压应力较浅，而且随着喷丸强度的增加，最大残余压应力也由表面移向了次表面。

Abstract:

Effects of laser peening and shot peening on residual stress fields performance of a GH742 superalloy were investigated. Compressive residual stresses in the surface layer were analyzed by the X-ray diffraction stress analyse tester. The characteristics of compressive residual stresses induce by these two kinds of surface enhancement processes were compared and the surface residual stress evlution was investigated under different high temperatures. The results show that both laser peening and shot peening can induce compressive residual stresses in surface layer, while the compressive residual stress layer is deeper for laser-peened specimens and the maximum residual compressive locate at surface; while for shot-peened specimens, the depth of compressive residual stress layer in thinner. Moreover, the maximum compressive residual stress moves from surface to subsurface with the increase of shot peening intensity.