9Ni钢手工电弧焊焊接接头组织与性能研究

Microstructure and Properties of Shielded Metal Arc Welding Welded Joints of 9Ni Steel

针对运输船用9Ni钢,研究手工电弧焊焊接工艺下9Ni钢焊接接头的组织与理化性能。组织分析表明,手工电弧焊下9Ni钢的焊缝组织由奥氏体和析出相组成,结晶形态为规则树枝状晶,且方向性较明显;焊接热影响区组织由板条马氏体组成,焊接粗晶区板条马氏体组织分布较均匀,偏析较分散,强韧性和机械性能不错。化学成分分析表明,9Ni钢板焊缝的化学成分与母材匹配性良好。焊接理化性能试验表明,手工电弧焊下焊接接头的低温韧性等性能满足标准要求,结合理论性能及断口分析,手工电弧焊焊接接头的低温韧性表现良好。

The microstructure and physical and chemical properties of 9Ni steel welded joints under manual arc welding process were investigated for transport ships.The microstructure analysis showed that the weld seam of 9Ni steel under manual arc welding consists of austenite and precipitated phases,with a regular dendritic crystal morphology and obvious directionality.The structure of the welding heat affected zone is composed of Flat noodles martensite.The Flat noodles martensite structure in the welding coarse grain zone is evenly distributed,the segregation is dispersed,and the strength,toughness and mechanical properties are good.The chemical composition analysis shows that the chemical composition of the weld of the 9Ni steel plate matches well with the base metal.The physical and chemical properties of the welded joint indicate that the low-temperature toughness of the manual arc welding joint meets the standard requirements.Combined with theoretical performance and fracture analysis,the low-temperature toughness of the manual arc welding joint is well-behaved.