【摘要】 研究了新型镍基GH4586B合金750℃下长期时效1500 h对组织及750℃和510 MPa持久性能的影响。利用扫描电子显微镜观察分析合金长期时效中的显微组织和750℃和510 MPa持久断口变化。结果表明,GH4586B在高温时效中未发现有害TCP相析出,晶界和晶内均析出碳化物,晶界析出碳化物呈弥散的颗粒状,并随时效时间的延长颗粒尺寸有增大的趋势,析出量亦不断增加;合金在750℃和510 MPa下的持久性能主要受晶界碳化物析出的影响,在750℃时效1500 h后750℃和510 MPa持久时间达到最大值,塑性相应最低;通过持久断口的形貌分析,合金750℃和510 MPa持久断裂具有韧性断裂特征。更多还原

【Abstract】 The relationship between 750 ℃ and 510 MPa stress-rupture properties and microstructure of a new Ni-base GH4586B alloy after long-term aging at 750 ℃ was investigated.The microstructure and 750 ℃ and 510 MPa stress-rupture properties were analyzed by means of SEM.The results indicate that TCP phase,a harmful phase to Ni-base alloy,is not observed in the aged alloy.The granular carbides in the alloy are precipitated at both grain boundary and grain interior,as well as the granular carbides precipitated at grain boundary show up as dispersed partictes and the particte size have a growing tendence with ageing time extension.The morphology of carbides at grain boundaries mainly influences 750 ℃ and 510 MPa stress-rupture properties of the aged alloy,and the stress-rupture strength reachs peak value and is ptasticity decreases after ageing at 750 ℃ for 1500 h.The stress-rupture for 750 ℃ and 510 MPa presents some ductile fracture features.更多还原