Zr微合金钢粗晶热影响区韧性和组织分析  

Analysis of toughness and microstructure in CGHAZ with high heat input welding in Zr micro-alloying steel

作　　者：石明浩[1] 张朋彦[1] 刘纪源[1] 朱伏先[1] 

机构地区：[1]东北大学材料与冶金学院轧制技术及连轧自动化国家重点实验室,沈阳110819

出　　处：《材料科学与工艺》2013年第3期1-5,共5页Materials Science and Technology

基　　金：国家自然科学基金重点资助项目(50834010)

摘　　要：为了获得大热输入焊接热影响区,利用实验室25 kg真空感应炉炼制不同Zr含量的实验用钢,在MMS-300型热模拟机上,对其试样进行热输入能量为100 kJ/cm,峰值温度1 400℃的大热输入焊接热模拟实验.借助电子探针(EPMA)等对CGHAZ中形成针状铁素体(AF)的夹杂物进行了微区分析,研究了夹杂物的化学组成和分布形态.结果表明:当Zr含量为0.003%时,焊接CGHAZ区低温冲击韧性最好,当Zr含量大于0.003%时CGHAZ的低温韧性随着Zr含量的增加呈下降趋势;CGHAZ中的奥氏体晶粒尺寸随小尺寸夹杂物数量的增加而降低;形成AF的夹杂物多以Zr的氧化物为核心表面析出MnS的复合氧化物夹杂,尺寸在0.5～3μm.To obtain high heat input welding heat affected zone（HAZ）,the 25 kg ingot was refined with vacuum induction furnace in laboratory,and high heat input welding thermal simulation test was conducted in 100 kJ/cm heat input at 1 400 ℃ top temperature by using of thermal simulator MMS-300.Composition and distribution of inclusions formed acicular ferrite（AF） in CGHAZ were studied by electron probe micro-analyzer（EPMA）.The results indicated that when Zr content is 0.003%,the best Charpy impact toughness of CGHAZ at low temperature was obtained,however,when Zr content is more than 0.003%,Charpy impact toughness of CGHAZ at low temperature decreased with the increasing of Zr content.Austenite grain size in CGHAZ decreased with the increasing of number of small inclusions.AF formed on Zr complex inclusions,which were mostly Zr oxide as the core and MnS precipitated on the surface,the size was in the range of 0.5~3 μm.

关 键 词：粗晶热影响区 针状铁素体 夹杂物 锆微合金钢 大热输入焊接 

分 类 号：TG142.1[一般工业技术—材料科学与工程]