【摘要】 利用扫描电镜对GH4586B合金在750℃下时效1500 h过程中的显微组织和室温拉伸断口进行观察分析。结果表明,GH4586B合金在时效过程中无有害TCP相(拓扑密堆相)析出,晶内析出尺寸差异较大的两种γ′相粒子,随着时效时间的延长,大尺寸的γ′相逐渐长大,形貌由球形逐步转变为方形,且间距也逐渐变大,这种γ′相析出的特征有利于合金强韧性的匹配;合金在室温下随着时效时间的延长,强度和塑性发生变化,时效500 h后合金具有较好的强度和塑性的匹配,这与γ′相析出的形貌、分布、数量直接相关;通过室温拉伸断口的形貌分析,合金断裂均具有塑性断裂特征。更多还原

【Abstract】 The microstructure of alloy GH4586B after aging at 750 ℃ for 1500 h and tensile fracture at room temperature was observed and analyzed with SEM.The results show that no harmful TCP phase precipitates during aging.There are two kinds of sizes γ′ particles precipitated in the grain,the bigger γ′ phase grows gradually and shapes from sphere to square and their spaces in between increase with the prolonging of aging time.The γ′ particles precipitation is beneficial to the matching of tensile strength and toughness.The room-temperature tensile strength and toughness are changed with the increasing of aging time,and the optimum matching of tensile strength and toughness appears at the aging time of 500 h,which is related to the pattern,distribution and amount of γ′ phase precipitation.The room-temperature tensile fractures are all presented as the ductile fracture feature.更多还原