喷丸强化对GH4096合金表面状态和疲劳性能的影响
Effect of Shot Peening on Surface State and Fatigue Performance of GH4096 Alloy
田伟 1伏宇 1张少平 1钟燕 1付锐 2李福林2
作者信息
- 1. 中国航发四川燃气涡轮研究院,四川成都 610500
- 2. 钢铁研究总院高温材料研究所,北京 100081
- 折叠
摘要
采用S1l0铸钢丸和Z300陶瓷丸对GH4096合金开展了喷丸强化试验,利用扫描电镜和三维轮廓仪分析了喷丸表面形貌,采用X射线衍射法分析了喷丸表面残余应力,采用扫描电镜EBSD分析了喷丸试样的截面显微组织,并对喷丸试样进行了 650 ℃低周疲劳试验.结果表明:随着喷丸强度的增大喷丸表面的粗糙度升高,相同喷丸强度下陶瓷丸喷丸表面的粗糙度低于铸钢丸喷丸表面的粗糙度.铸钢丸喷丸表面的残余压应力在-860～-1000 MPa之间,随着喷丸强度的增加残余压应力略有降低;陶瓷丸喷丸表面的残余压应力在-1000～-1100 MPa之间,随着喷丸强度的增加残余压应力略有增加.GH4096合金喷丸后表面发生塑性形变,形成弹丸坑形貌,出现晶界弯曲,产生晶格畸变,造成大量位错塞集,形成密集分布的小角度晶界,晶粒取向也随之改变.喷丸强化可提高GH4096合金650 ℃高温下的低周疲劳寿命,复合喷丸对疲劳寿命的提升效果最明显,相同喷丸强度下陶瓷丸的强化效果优于铸钢丸.喷丸强化后试样的疲劳裂纹多萌生于强化层之下的亚表面,喷丸强化的效果受表面粗糙度、残余应力及强化层深度等共同影响.
Abstract
The shot peening experiment was conducted on S110 cast steel shot and Z300 ceramic shot,the morphology of shot peening surface was observed by SEM and three-dimensional contour instrument.The residual stress of shot peening surface was tested by X-ray diffraction,and the microstructure of cross section of shot peening layer was analyzed by OM and EBSD.The result shows that with the increase in shot peening intensity,the roughness of shot peening surface is increased.The roughness of ceramic shot peening surface is lower than that of cast steel shot.Residual compressive stress on the cast steel shot peening surface is between-860 MPa to-1000 MPa and with the increase in shot peening intensity,the residual compressive stress is slightly reduced.Residual compressive stress on the shot peening surface ceramic is between-1000 MPa to-1100 MPa,and with the increase in shot peening intensity,the residual compressive stress is slightly increased.After shot peening,projectile pits are formed on GH4096 alloy surface,plastic deformation occurs,grain boundaries are curved,and lattice deformation occurs,which causes a lot of dislocation set and low angle grain boundaries,and the grain orientation changes.The low-cycle fatigue life of GH4096 alloy at 650 ℃ can be improved by shot peening.The improvement effect of double shot peening on fatigue life is the most obvious,and strengthening effect of ceramic shot peening is better than that of cast steel shot peening.The strengthening effect of shot peening is mutually influenced by residual stress,surface roughness,and depth of strengthening layer.
关键词
GH4096合金/喷丸强化/表面形貌/残余应力/显微组织/疲劳性能Key words
GH4096 alloy/shot peening/surface morphology/residual stress/microstructure/fatigue performance引用本文复制引用
出版年
2024
NETL
NSTL
万方数据