焊丝成分对耐候钢焊接飞溅及焊缝组织和性能的影响

Effects of Welding Wire Composition on Welding Spatter and Weld Microstructure and Properties of Weather-resistant Steel

针对目前采用现有的焊接材料和焊接工艺在耐候钢MAG焊中出现的焊接飞溅大、焊丝熔敷效率低、电弧稳定性差、焊缝表面成形不良等问题,对比研究了自制超低碳耐候钢焊丝与商用CHW-55CNH耐候钢焊丝的飞溅率大小,并分析了两种焊丝熔敷金属的组织和性能。结果表明,超低碳耐候钢焊丝的焊接飞溅率比CHW-55CNH焊丝降低了78.8%。超低碳焊丝熔敷金属中针状铁素体组织的数量明显增加,而先共析铁素体和侧板条铁素体数量减少,且熔敷金属的晶粒尺寸更加细小、均匀。超低碳焊丝熔敷金属的抗拉强度为640 MPa,室温下冲击吸收功为163 J。而耐候钢焊丝CHW-55CNH抗拉强度为637 MPa,室温下冲击吸收功为173 J,两种焊丝熔敷金属的强韧性能相当。

Aiming at the problems such as high welding spatter, low deposition efficiency, poor arc stability, poor forming of weld surface, etc, in MAG welding of weather-resistant steel welded by the existing welding materials and welding technology, the spatter rate of self-made ultra-low carbon weather-resistant steel welding wire and commercial CHW-55CNH weather-resistant steel welding wire was compared and the microstructures and properties of two welding wire deposited metals were analyzed. The results show that the spatter rate of ultra-low carbon welding wire is 78.8% lower than that of CHW-55CNH wire. The number of acicular ferrite in ultra-low carbon welding wire deposited metal increases obviously and the numbers of proeutectoid ferrite and ferrite side-plate decrease. The grain size of deposited metal is smaller and more uniform. The tensile strength of ultra-low carbon welding wire deposited metal is 640 MPa and the impact absorption energy at room temperature is 163 J. The tensile strength of CHW-55CNH weather-resistant steel welding wire deposited metal is 637 MPa and the impact absorption energy at room temperature is 173 J. The strength and toughness of the two welding wire deposited metals are equal.