Cr含量对1000 MPa级高强钢熔敷金属组织演变的作用机制  

Effect of Cr content on the microstructure evolution in weld metal for 1000 MPa grade high strength steel

作　　者：冯伟 于庭祥 陈波 张庆素 才红广 张碧莹 马强 FENG Wei;YU Tingxiang;CHEN Bo;ZHANG Qingsu;CAI Hongguang;ZHANG Biying;MA Qiang(Harbin Well Welding Co.,Ltd.,Harbin,150060,China;Harbin Welding Institute Limited Company,Harbin,150028,China;Dalian Jinzhou Heavy Machinery Group Co.,Ltd.,Dalian,116100,China;Jiangsu Rongda Material Corrosion Inspection Co.,Ltd.,Wuxi,214000,China)

机构地区：[1]哈尔滨威尔焊接有限责任公司,哈尔滨150060 [2]中国机械总院集团哈尔滨焊接研究所有限公司,哈尔滨150028 [3]大连金州重型机器集团有限公司,大连116100 [4]江苏容大材料腐蚀检验有限公司,无锡214000

出　　处：《焊接学报》2024年第9期76-83,共8页Transactions of The China Welding Institution

基　　金：黑龙江省重点研发计划项目(2022ZX04A01)。

摘　　要：设计开发了5种不同Cr含量的1000 MPa级高强钢埋弧焊材,采用丝极埋弧焊制备了Cr含量为0%~0.9%的熔敷金属,利用OM、SEM、TEM和CLSM等微观组织表征方法研究Cr含量对1000 MPa级高强钢熔敷金属组织演变的影响,并通过拉伸和冲击试验评估其力学性能.结果表明,1000 MPa级高强钢熔敷金属随着Cr含量提高,铁素体转变起始温度由723.3℃提高到740.2℃,贝氏体转变起始温度由470.2℃降低到458.5℃,铁素体转变温度区间扩大,高Cr熔敷金属中贝氏体转变速率较快,熔敷金属中针状铁素体和贝氏体铁素体增加,M-A组元由弥散分布逐渐呈链条状偏聚,先共析铁素体与残余奥氏体减少.熔敷金属冲击断裂形式由低Cr的韧性断裂向高Cr的准解理断裂转变,熔敷金属拉伸强度不断提高,相比于无Cr的熔敷金属,0.9%Cr的熔敷金属抗拉强度和屈服强度分别提高12.4%和17.0%,熔敷金属冲击吸收能量先提高后降低,在−40℃条件下,0.6%Cr的熔敷金属的低温韧性最高为84 J,熔敷金属Cr含量为0.6%时强韧性匹配效果最佳.Five kinds of submerged arc welding materials of 1000 MPa grade high strength steel with different Cr content were designed and deposited metals with Cr content of 0%~0.9%were prepared by wire electrode submerged arc welding.OM,SEM,TEM and CLSM were used to study the effect of Cr content on the microstructure evolution of 1000 MPa grade high strength steel,and the mechanical properties were evaluated by tensile and impact tests.The results show that,with the increase of Cr content,the initial temperature of ferrite transition increases from 723.3℃to 740.2℃,and the initial temperature of bainite transition decreases from 470.2℃to 458.5℃.The range of ferrite transition temperature expands,and the bainite transition rate is faster in high Cr deposited metal.The acicular ferrite and bainite ferrite in deposited metal increased,the M-A component gradually showed chain segregation from dispersion,and the proeutectoid ferrite and residual austenite decreased.The impact fracture of deposited metal changes from ductile fracture with low Cr to quasi-cleavage fracture with high Cr.Compared with 0 Cr,the tensile strength and yield strength of 0.9%Cr are increased by 12.4%and 17.0%,respectively.The impact absorption energy of deposited metal increases first and then decreases.At−40℃,the low temperature toughness of deposited metal with Cr content of 0.6%is the highest,which is 84 J.When Cr content of deposited metal is 0.6%,the matching effect of strength and toughness is the best.

关 键 词：1000 MPa级高强钢 熔敷金属 Cr元素含量 组织演变 激光扫描共聚焦显微镜 

分 类 号：TG423[金属学及工艺—焊接]