Zr对海底管线钢焊丝熔敷金属组织和冲击韧性的影响

Effect of Zr on microstructures and impact toughness of deposited metal by self-shield flux cored wire on submarine pipeline steel

制备了4种不同Zr含量的自保护药芯焊丝,采用自保护焊接方法制作了熔敷试板。研究了Zr含量对自保护药芯焊丝熔敷金属组织和冲击韧性的影响。结果表明,添加Zr后熔敷金属夹杂物主要为Al-Mg-Zr的氮化物和氧化物;随着Zr含量的增加,熔敷金属组织逐渐均匀细化,且针状铁素体占比逐渐增加,夹杂物数量增加、尺寸减小。夹杂物和晶粒的细化以及针状铁素体的增多是熔敷金属冲击韧性提高的主要原因,当Zr添加量为2%时,熔敷金属在-40℃下平均冲击吸收能量可达132J。

Four types of self-shield flux cored wires with different Zr content were prepared in laboratory and the deposited metals were made by self-shielded flux cored welding.The effect of Zr on microstructures and impact toughness of deposited metal of self-shield flux cored wire was studied.The results show that the inclusions of Zr-additioned deposited metal are mainly nitrides and oxides of Al-Mg-Zr.With the increase of Zr content,the microstructure of deposited metal is gradually uniform and refined,and the proportion of acicular ferrite increases gradually;The number of inclusions also increases with the increase of Zr content and the size of inclusions decreases with the increase of Zr content.The improvement of impact toughness of deposited metal is attributed to the increase of acicular ferrite and the refinement of inclusions and grains.When the content of Zr is 2%,the average impact toughness of deposited metal at-40 ℃is up to 132 J.