摘要
白鹤滩百万千瓦水电机组转轮的上冠、叶片、下环之间全部采用HS13/5L马氏体不锈钢焊丝进行MAG焊接,由于HS13/5L属于13Cr型超级马氏体不锈钢,其MAG焊熔敷金属韧性低于母材,直接影响转轮的性能,为此对该熔敷金属进行微观组织表征及力学性能测试。熔敷金属的焊态组织为淬火马氏体+枝晶间δ铁素体以及部分回火马氏体,回火组织为回火马氏体+逆变奥氏体;590℃×8 h回火处理使熔敷金属的韧性得到明显改善,在Ac1点附近温度回火而形成的逆变奥氏体是韧性提高的重要韧化相。正火+回火的热处理工艺能进一步提高熔敷金属的韧性,冲击功基本稳定在100 J以上,较590℃×8 h热处理工艺提高了10~20 J,HS13/5L熔敷金属力学性能优异,满足白鹤滩水轮机转轮的焊接要求。
The HS13/5L martensitic stainless steel welding wire is used for MAG welding between the upper crown, blade and lower ring of the runner of Baihetan million kilowatt hydropower unit. Because HS13/5L belongs to 13Cr type super martensitic stainless steel, the toughness of its MAG welding deposited metal is lower than that of the base metal, which directly affects the performance of the runner. Therefore the microstructure and mechanical properties of the deposited metal were studied. The welded microstructure of the deposited metal is quenched martensite, interdendritic delta ferrite and tempered martensite in some reheat zone, and the tempered microstructure is tempered martensite, reversed austenite. 590 ℃×8 h tempering treatment significantly improves the toughness of deposited metal, the reversed austenite formed by tempering at a temperature near the Ac1is an important toughening phase. The normalizing+tempering heat treatment process can improve the toughness of the deposited metal to a certain extent, and the impact toughness is basically stable above 100 J,which is 10~20 J higher than the existing heat treatment process of 590 ℃×8 h. HS13/5L deposited metal has excellent mechanical properties, meeting the welding requirements of turbine runner in Baihetan power station.
作者
焦帅杰
贾玉力
周宝金
韩莹
徐亦楠
郝增龙
JIAO Shuaijie;JIA Yuli;ZHOU Baojin;HAN Ying;XU Yinan;HAO Zenglong(Harbin Welding Institute Limited Company,Harbin 150028,China;Harbin Well Welding Co.Ltd.,Harbin 150060,China)
出处
《电焊机》
2022年第11期68-74,共7页
Electric Welding Machine
关键词
超级马氏体不锈钢
逆变奥氏体
熔敷金属
冲击韧性
正火处理
supermartensitic stainless steel
reversed austenite
deposited metal
impact toughness
normalizing treatment
