大口径厚壁G115耐热钢管TIG+SMAW工艺及性能分析  

TIG+SMAW Process and Properties Analysis of Large Diameter Thickwalled G115 Heat-Resistant Steel Pipe

作　　者：郭新芳 崔凤友 范宏举 万夫伟 陈澜文 刘鹏[2] 冯雪雁 GUO Xinfang;CUI Fengyou;FAN Hongju;WAN Fuwei;CHEN Lanwen;LIU Peng;FENG Xueyan(Power China Nuclear Engineering Co.,Ltd.,Jinan 250102,China;School of Materials Science and Engineering,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]中国电建集团核电工程有限公司,山东济南250102 [2]山东建筑大学材料科学与工程学院,山东济南250101

出　　处：《电焊机》2022年第8期101-107,共7页Electric Welding Machine

基　　金：山东省自然科学基金(ZR2016JL017)。

摘　　要：采用TIG+SMAW方法对超超临界电站锅炉用大口径厚壁G115耐热钢管进行焊接,并对焊接接头不同壁厚位置进行微观组织结构特征及其力学性能分析。结果表明,焊缝区、热影响区及熔合区存在较为明显的组织转变,焊缝区主要由回火马氏体组织组成,热影响区以板条马氏体组织为主,母材呈现片状马氏体组织,且由母材至焊缝,晶粒逐渐细化,焊缝以等轴晶和柱状晶组织为主。从母材到焊缝,接头硬度分布呈现逐渐升高的趋势,但在熔合线附近硬度略有下降,其中热影响区最低,焊缝区硬度最高。接头冲击韧性试验表明,热影响区根部冲击吸收功明显高于焊缝,填充区则略低于焊缝,焊缝区冲击吸收功平均值为43.89 J,热影响区的冲击功平均值为66.49 J,接头冲击韧性较好,能满足实际使用要求。TIG+SMAW method is used to weld large diameter thick-walled G115 heat-resistant steel pipe used for ultrasupercritical power plant boiler, and the microstructure and mechanical properties of the joint are analyzed. The results show that there are obvious microstructural transformation in weld zone(WZ), heat affected zone(HAZ) and fusion zone. The WZ is mainly composed of tempered martensite microstructure, HAZ is mainly composed of lath martensite microstructure, and base metal appears lamellar martensite microstructure. From the base metal to the weld, the grain gradually refines, the microstructure of weld is mainly equiaxed grain and columnar grain, and the joint hardness distribution gradually increases, but slightly decreases near the fusion line, in which the minimum value of joint hardness is 220.6 HV0.2(HAZ) and the maximum value is 302.8 HV0.2(WZ). In addition, the joint impact test shows that the impact absorption energy of the root of HAZ is significantly higher than that of the weld, while that of the filled zone is slightly lower than that of the weld. The average values of the impact absorption energy in WZ and HAZ are 43.89 J and 66.49 J respectively. The impact toughness of the welded joint is good, which can meet the actual application requirements.

关 键 词：G115耐热钢 熔化焊 大口径厚壁管 显微组织 力学性能 

分 类 号：TG457[金属学及工艺—焊接]