国产P91钢焊接接头热影响区各亚区域的热处理模拟  

Thermal Treatment Simulation for Each Subregions in Heat Affected Zone of Domestic P91 Steel Welded Joints

作　　者：方利鹏 要玉宏[1] 金耀华[1] 冯琳杰[2] 张巍 刘福广 FANG Lipeng;YAO Yuhong;JIN Yaohua;FENG Linjie;ZHANG Wei;LIU Fuguang(School of Materials and Chemical Engineering,Xi'an Technological University,Xi'an 710021,China;Huaneng Pingliang Power Generation Co.,Ltd.,Pingliang 744000,China;Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710032,China)

机构地区：[1]西安工业大学材料与化工学院,西安710021 [2]华能平凉发电有限责任公司,平凉744000 [3]西安热工研究院有限责任公司,西安710032

出　　处：《机械工程材料》2024年第10期55-64,共10页Materials For Mechanical Engineering

基　　金：华能集团总部科技项目(HNKJ21-HF254)。

摘　　要：采用不同温度(800,850,950,1 300℃)×25 min的正火+755℃×60 min回火处理分别模拟P91钢接头热影响区不同亚区域,采用650℃×200 h高温加速时效热处理工艺模拟服役50 000 h工况,通过对比热模拟和实际接头试样研究了服役50 000 h后P91钢焊接接头热影响区不同亚区域的组织及性能。结果表明:粗晶区、细晶区服役态热模拟试样的马氏体板条形态以及MX相、M_(23)C_(6)碳化物和Laves相的数量、分布、颗粒尺寸与实际接头相应亚区域均十分接近;除粗晶区外,热影响区各亚区域服役态热模拟试样和实际服役接头相应区域的平均晶粒尺寸十分接近,相对误差不超过12.5%,显微硬度和微型杯突力学性能相近,强度、韧度和断裂挠度率相对误差均在5%以内,断口呈典型微孔聚集型韧性断裂特征;热影响区部分相变区显微硬度最小,为191 HV,在细晶区和粗晶区硬度大幅上升,在熔合线处达到最大,为314 HV;热影响区粗晶区的微型杯突强度最大,塑性最差,部分相变区的强度最低,塑性最好;相比粗晶区,部分相变区的颈缩程度更高,韧窝更大更深。The different subregions in heat affected zone of P91 steel welded joints were simulated by different temperature (800,850,950,1 300℃)×25 min normalizing+755℃×60 min tempering,and the 50 000 h service situation was simulated by 650℃×200 h high temperature accelerated aging heat treatment process.The microstructure and properties of different subregions in heat affected zone of the P91 steel welded joint after 50 000 h service were studied by comparing those of the heat simulation soumples and the actural joint samples.The results show that after service the morphology of martensitic lath,and the quantity,distribution and particle size of MX phase,M_(23)C_(6) carbide and Laves phase of the thermal simulation samples of coarse grained and fine grained regions were very close to those of the corresponding subregions of actural welded joint.In addition to the coarse grained region,the average grain size of the each subregion thermal simulation samples and the corresponding subregions of welded joint after service was very close,and the relative error was no more than 12.5%.The microhardness and small punch mechanical properties were also similar,and the strength,toughness and fracture deflection rate relative errors were less than 5%.The fracture had typical microporous aggregation ductile fracture characteristics.The microhardness was the smallest in the partial phase change region of heat affected zone,which was 191 HV.The hardness increased greatly in the fine grained and coarse grained region,and reached the maximum at the fusion line,which was 314 HV.The small punch strength and plasticity were the highest and the plasticity was the worst in coarse grained region,while the strength and plasticity were the lowest and the plasticity was the best in partial phase change region.Compared with coarse grained region,partial phase change region had higher necking degree and larger and deeper dimple.

关 键 词：P91钢 焊接接头 热影响区 热处理模拟 加速时效 显微硬度 微型杯突力学性能 

分 类 号：TG142.24[一般工业技术—材料科学与工程]