制氢转化炉集气管裂纹失效原因分析  

Damage Mechanisms of Incoloy 800H Alloy Casting Under Servicing Conditions

作　　者：于磊 刘凯 李本锋 Lei YU;Kai LIU;Benfeng LI(Zibo Haiyi Fine Chemical Co. Ltd., Zibo 255000, China)

机构地区：[1]淄博海益精细化工有限公司

出　　处：《腐蚀科学与防护技术》2019年第2期247-250,共4页Corrosion Science and Protection Technology

摘　　要：采用光学金相、扫描电镜、电子探针、晶粒度测量等手段对制氢转化炉Incoloy 800H合金材料高温氧化状态下服役后的组织损伤特征进行分析,借助Wagner理论分析合金材料服役过程中的元素偏析与材料开裂的关联性。结果表明,Incoloy 800H合金材料在高温氧化环境服役过程中发生了晶界氧化、元素偏析,合金组织经历合金元素氧化-碳化物分解-碳化物偏聚的组织演变,弥散强化减弱,合金组织晶粒度粗大;服役过程贫碳化物区晶界抗高温蠕变能力下降,多重应力综合影响导致Incoloy 800H合金材料裂纹的萌生及扩展。Cracking failure of gas collection tubes made of Incoloy 800H casting for a hydrogen converter after service for 7 a was investigated by means of OM,SEM and EPMA,with special attention on grain size assessment and microstructure characteristics of Incoloy 800H casting along and/or nearby the cracking failure. The results show that internal oxidation preferentially along grain boundaries and element segregation took place in the inner wall of Incoloy 800H casting during long term service in corrosive atmosphere at high temperature, where the alloy might experience an evolution of reaction process such as internal oxidation, followed by carbide decomposition and then by carbide segregation, as a result, the grains were coarsened and the precipitation strengthening effect was weakened, as well as the creep resistance of the carbon depleted region was then degraded, which finally leads to the initiation and propagation of cracks in Incoloy 800H alloy under the action of various type of stresses presented in the facility during service.

关 键 词：Incoloy 800H合金 金相组织 元素偏析 开裂 

分 类 号：TG174[金属学及工艺—金属表面处理]