摘要
采用镦饼、冲孔、机加内孔、扩孔工艺生产的GH4099合金锻件,经粗加工后发现其外圆面存在4条长约10 mm的线性缺陷。使用金相显微镜、扫描电子显微镜对锻件裂纹显微组织、断口进行观察,对其化学成分进行检测,对裂纹产生的原因进行分析。结果表明:GH4099合金锻件开裂的主要原因是由于Al元素在晶界处偏析,形成硬质有害的β-NiAl相而引起晶界弱化造成的,裂纹扩展方式为沿晶开裂;裂纹附近的合金在高温下与O元素结合形成氧化物硬质颗粒,在变形过程中形成二次细小裂纹。
GH4099 alloy forgings were produced by upsetting,punching,machining inner hole and reaming hole.After rough machining,four linear defects of about 10 mm length were found on the outer surface of a forging.Microstructure and chemical composition analysis near the cracks and fracture surface analysis were carried out by optical microscopy(OM)and scanning electron microscopy(SEM)to find out the cracking cause.The results show that the cracking of the GH4099 alloy forging was mainly caused by the segregation of Al element at grain boundaries,leading to hard and harmfulβ-NiAl phase,which weakened the grain boundaries.The cracks propagated along the grain boundaries.The alloy near the cracks were combined with oxygen to form hard oxide particles at high temperature,leading to fine secondary cracks in the deformation process.
作者
王哲
冯晓艳
蔡松
王永强
WANG Zhe;FENG Xiao-yan;CAI Song;WANG Yong-qiang(Shanxi Hongyuan Aviation Forging Co.,Ltd.,Shaanxi Xianyang 713801,China;AVIC Metal Test Technology Co.,Ltd.,Xi’An 710018,China)
出处
《失效分析与预防》
2023年第6期412-416,共5页
Failure Analysis and Prevention
