大线能量焊接钢板热影响区性能劣化机理分析及对策研究  

Welding heat affected zone failure mechanism analysis and improvement method research of steel with high heat input

作　　者：祝凯[1] 杨健[1] 王睿之[1] 沈建国[1] 

机构地区：[1]宝山钢铁股份有限公司研究院,上海201900

出　　处：《内蒙古科技大学学报》2012年第3期300-304,共5页Journal of Inner Mongolia University of Science and Technology

摘　　要：对厚钢板大线能量焊接后热影响区(HAZ)失效机理进行了分析,研究了镁处理工艺对大线能量焊接HAZ性能的改善作用并进行了评价.明确了粗晶热影响区脆化是由于晶粒粗大及不良组织而引起,粗大的奥氏体晶粒是焊接热影响区韧性恶化的主要原因,抑制焊接HAZ晶粒长大是改善厚钢板可焊性的关键因素.用真空感应炉分别冶炼了不同成分的钢,研究Mg处理对HAZ的改善效果.结果表明含Mg钢HAZ的低温韧性较比不含Mg钢有较大幅度提高.通过激光高温显微镜原位观察发现,含Mg钢在1 400℃保温300 s后奥氏体晶粒仍然保持着细小的结构,这主要归功于Mg添加后生成的细小粒子所产生的钉扎作用.该发现为改善厚板HAZ韧性提供了一种有效方法.The heat affected zone （HAZ） failure mechanism of thick plate was analyzed,and the effect of Mg addition on inhibiting austenite grain growth of Ti-bearing low carbon steels was studied. Two steels with different Mg contents were prepared using a laboratory vacuum. The performance of HAZ under weld thermal simulations was investigated. The HAZ toughness was improved evidently. It was found through in-situ observation by a eonfoeal scanning laser microscope that the austenite grain in the HAZ of steel with Mg addition still presents fine-grained structure after undergoing 1 400 ℃ heating for 300 s. This inhibition of austenite grain growth was mainly attributed to the formation of pinning particles after the addition of Mg. The obtained results propose a potential method for improving HAZ toughness of thick plate steels.

关 键 词：低碳钢 热影响区 失效分析 钉扎机制 

分 类 号：TG401[金属学及工艺—焊接]