喷丸强化对DZ4定向凝固高温合金高温旋转弯曲疲劳性能的影响

Influence of Shot Peening on High Temperature Fatigue Property of DZ4 Directionally Solidified Superalloy

对DZ4定向凝固高温合金进行喷丸强化。利用表面轮廓仪、硬度计和扫描电镜等设备研究了表面粗糙度、显微硬度、组织结构等表面完整性的变化。在820℃高温下进行了光滑和缺口试样的旋转弯曲疲劳试验。结果表明,由于喷丸强化效应和弱化效应基本相当,喷丸强化工艺对提高DZ4定向凝固各向异性材料光滑试样高温疲劳性能效果不显著;但对于具有应力集中的缺口试样,由于喷丸弱化作用引起的应力集中效应被缺口应力集中所掩盖,喷丸强化效果比较显著。

DZ4 directionally solidified superalloy was employed to investigate the effect of shot peening on surface integrity such as topography,surface roughness,microstructure,et al.by the methods of surface configuration tester,hardness tester and SEM.Fatigue properties of unpeened and shot-peened specimens of DZ4 superalloy were determined by rotating bending fatigue test at 820℃.The results show that shot peening improves the fatigue property of DZ4 directionally solidified superalloy,but the modification effect for notched specimens is greater than smooth ones.The comprehensive effect of shot peening including beneficial and detrimental factors was analyzed.