高温蒸汽管道用P91钢服役过程不均匀软化及形成机制研究  

Study on Non-uniform Softening and Formation Mechanism of P91 Steel for High Temperature Steam Pipeline during Service

作　　者：王金海[1] 王艳松 刘福广[2] 刘立营[2] 李刚[1] 韩天鹏 WANG Jinhai;WANG Yansong;LIU Fuguang;LIU Liying;LI Gang;HAN Tianpeng(Huaneng International Power Co.,Ltd.,Dezhou Power Plant,Shandong 253024,China;Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,China)

机构地区：[1]华能国际电力股份有限公司德州电厂,山东德州253024 [2]西安热工研究院有限公司,陕西西安710054

出　　处：《铸造技术》2021年第6期517-520,526,共5页Foundry Technology

摘　　要：使用碳硫分析仪、氧氮氢测定仪、光学显微镜、扫描电镜、透射电镜、硬度计、万能实验机等对P91原始钢和长期服役钢的化学成分、显微组织、力学性能等进行了分析。结果表明,服役后的P91钢所有元素均在标准之内,符合标准要求,其中低硬度区域的力学性能不满足使用条件;P91钢内部组织发生变化,部分马氏体转变为块状铁素体,晶内与晶界存在大量的析出物(主要为M_(23)C_(6)相),且部分析出相在晶界处聚集形成短链状。组织的粗化和碳化物的聚集长大是导致P91钢长期服役后硬度与强度降低的主要原因。The chemical composition,microstructure and mechanical properties of P91 original steel and long-service steel were analyzed by means of carbon and sulftir analyzer,oxygen,nitrogen and hydrogen tester,optical microscope,scanning electron microscope(SEM),transmission electron microscope(TEM),hardness tester and universal tester.The results show that all elements of P91 steel after service are within the standard and meet the requirements of the standard,among which the mechanical properties of the low hardness area do not meet the service conditions.The microstructure of P91 steel is changed,part of martensite is transformed into massive ferrite,there are a lot of precipitates(mainly M_(23)C_(6) phase)in grain and grain boundary,and part of precipitates gather at grain boundary and form short chains.The coarsening of microstnicture and the accumulation and growth of carbide are the main reasons for the decrease of hardness and strength of P91 steel after long-term service.

关 键 词：P91钢 力学性能 显微组织 硬度 

分 类 号：TG142.41[一般工业技术—材料科学与工程]