Zr-Ti复合脱氧对低合金高强度钢CGHAZ组织和韧性的影响  

Effect of Zr-Ti combined deoxidation on microstructure and toughness in coarse-grained region of heat-affected zone of high strength low alloy steels

作　　者：魏然[1] 吴开明[1] 王红鸿[1] 姚永宽[2] 王道远[2] 孟令东[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10期71-74,116-117,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：对Zr-Ti复合脱氧低合金高强度30 mm厚钢板采用气体保护焊进行多层多道焊接,利用光学显微镜,扫描电子显微镜及能谱分析对焊接热影响区组织进行了观察与分析.结果表明,该区域存在大量微米、亚微米级的复合铬、钛氧化物夹杂,呈细小弥散分布,没有发现条状MnS夹杂物的存在.夹杂物粒子在晶界和晶内析出,钉扎奥氏体晶界,有效抑制了奥氏体晶粒长大,晶粒粗化不明显.在粗晶区奥氏体晶粒内部优先形成的针状铁素体,能有效分割奥氏体晶粒,细化组织.焊接热影响区粗晶区的力学性能测试表明,Zr-Ti复合脱氧技术使焊件具有良好的低温冲击韧性.The 30 mm thick plates of a Zr-Ti killed microalloyed low alloy high strength steel was welded utilizing gas sheilded arc welding.The microstructure in the heat-affected zone was studied by means of optical microscopy and electron microscopy.Many micron and sub-micron composite Zr-Ti oxides were observed and evenly dispersed in the heat-affected zone whereas no cluster-like MnS was observed.Oxide particles were precipitated on grain boundaries and in grain interior.They pinned the grain boundaries and inhibited the growth of austentite grains.The austenite did not coarsen remarkably.The acicular ferrite grains formed in the coarse-grained region of heat-affected zone effectively partitioned austenite grains and thus refined microstructures.The mechanical test of coarse-grained heat-affected zone showed that the Zr-Ti killed microalloyed steel plates had good low temperature toughness.

关 键 词：低合金高强度钢 Zr—Ti复合脱氧 气体保护焊 冲击韧性 组织细化 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG401[金属学及工艺—金属材料]