Zr-Ti复合微合金化高强高韧结构钢的焊接性  

Weldability of Zr-Ti microalloyed high-strength high-toughness structural steels

作　　者：卢伟煜[1] 吴开明[1] 王红鸿[1] 雷玄威[1] 尹雨群[2] 姚永宽[2] 王道远[2] 

机构地区：[1]武汉科技大学国际钢铁研究院,武汉430081 [2]南京钢铁集团有限公司,南京210035

出　　处：《焊接学报》2012年第8期49-52,115,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金重点资助项目(50734004)

摘　　要：通过热模拟试验建立了F550钢板的焊接热影响区连续冷却转变曲线,研究了焊接热影响区组织转变与性能变化规律.结果表明,钢板经过Zr-Ti复合脱氧处理后,在钢中形成了许多可以在焊接过程中钉扎焊接粗晶区奥氏体晶界的细小弥散Zr-Ti复合氧化物粒子,同时采用低碳设计,并进行镍、铬、铜、钼的适量合金化,所以在较大焊接热输入范围内(25～100 kJ/cm)可以获得优良强韧性的贝氏体组织,M-A组元细小呈弥散分布.50 kJ/cm的实际埋弧焊接粗晶区V形冲击韧性结果表明,该钢焊接粗晶区在-60℃下具有良好的低温冲击韧性.The continuous cooling transformation curves(SH-CCT) in the heat affected zone(HAZ) of F550 steel plate were established with thermal simulation,and the microstructural evolution and mechanical properties of the HAZ were investigated.Experimental results showed that fine Zr and Ti complex oxides dispersed in the steel weld,which have pinning effect on the austenite grain in the coarse-grained heataffected zone(CGHAZ) due to the combined deoxidation of Zr and Ti in the steel plate.Meanwhile,the low carbon content and proper addition of Ni,Cr,Cu and Mo were adopted in the design of high-strength steel.Consequently,the bainitic microstructure with small amount of dispersing M-A islands was obtained in the HAZ in a large range of heat input(25-100 kJ/cm).The results of V-notch impact test of CGHAZ welded by submerged arc welding with heat input of 50 kJ/cm indicated that the impact toughness of F550 steel was good at-60 ℃.

关 键 词：Zr-Ti复合微合金化 SH—CCT曲线 焊接性能 低温冲击韧性 埋弧焊 

分 类 号：TG445[金属学及工艺—焊接]