机构地区: 东北大学材料与治金学院材料各向异性与织构工程教育部重点实验室
出 处: 《金属热处理》 2010年第5期15-19,共5页
摘 要: 为了考察长期时效对GH4586合金动态裂纹扩展的影响,测定了经不同时效时间时效后合金的动态断裂韧性JId。采用光学显微镜、扫描电子显微镜对合金的显微组织及断口形貌进行了分析,探讨了GH4586合金在750℃长期时效过程中合金的组织变化对动态断裂韧性的影响规律。研究表明,GH4586合金经200 h时效后,动态断裂韧性JId从166 N/mm降至86 N/mm,在随后的800 h时效中,动态断裂韧性JId变化不大。时效时合金中的碳化物由在晶界断续析出转变为连续析出,导致了合金的动态断裂韧性降低。而时效500 h后,拓扑密排(TCP)相的析出削弱了晶界碳化物对动态断裂韧性的影响,这是GH4586合金动态断裂韧性变化减缓的主要原因。 In order to investigate the effects of long-term aging on dynamic crack propagation resistance,the dynamic fracture toughness(JId) of GH4586 alloy was measured.Both the optical microscope and scanning electron microscope(SEM) were used to examine the microstructure and fracture surface of the alloy.It is found that JId decreases from 166 N/mm to 86 N/mm after 200 h aging treatment,and it doesnt change remarkable within 800 h aging treatment.During the aging treatment,the morphology of carbides changes from discontinuous to continuous along the grain boundary,such change caused the decreasing of JId.However,the change of JId is lowered after precipitation of TCP phase.