热输入对B610CF钢焊接接头性能的影响

Influence of welding energy input on welded joints of B610CF steel

采用混合气体保护焊和焊条电弧焊2种焊接方法,对低碳贝氏体B610CF钢在不同热输入下进行焊接,研究不同热输入对B610CF钢焊接接头性能的影响。冲击韧性试验研究和微观金相组织分析表明,不同热输入对焊缝区显微组织影响明显,随着热输入的增大,焊缝区贝氏体含量下降、晶粒变得较粗大,焊缝冲击韧性明显下降;但热影响区组织没有明显差异,且冲击韧性也没有明显差异。拉伸试验、弯曲试验结果表明,不同热输入对焊接接头的强度和的影响不明显。为了提高焊接接头的性能,不宜采用过大的热输入。

The influence of heat input on welded joints of B610 CF steel using metal active gas welding（ MAG）and shielded metal arc welding（SMAW） method was investigated. Results of mechanical property experiments and metallographic experiments showed that the quantity of bainite decreases and crystalline grain size becomes larger,and the impact toughness decreases with the increase of heat input in weld metal. But in heat affected zone, there was no distinct difference in microstructure and impact toughness. And there was no distinct difference in tensile strength and plasticity in welded joints. In order to improve the quality of B610 CF steel welded joints, larger heat input should be avoided.