论文部分内容阅读
采用ER2209焊丝对双相不锈钢SAF2205与微合金管线钢X65进行熔化极气体保护焊接,获得了具有良好力学性能的异种钢焊接接头.焊接接头不同区域显微组织观察和成分分析表明,微合金钢与不锈钢焊缝间存在异金属熔合区和第二类边界线,熔合区存在Ni、Cr的浓度梯度分布,且硬度高于两侧的焊缝和母材.通过宏观拉伸、缺口拉伸和低温冲击实验测试了焊接接头的力学性能,并获得了接头不同部位在1mol.L-1NaCl溶液中的极化曲线.拉伸试样断裂发生于强度相对较低的微合金钢母材.焊缝金属的缺口拉伸强度和冲击韧性均略低于双相不锈钢母材,但腐蚀电位略高于母材.微合金钢热影响区与母材力学性能相当,腐蚀电位略高于母材.
The ER2209 welding wire was used to weld the duplex stainless steel SAF2205 and the micro-alloyed pipeline steel X65 by gas-tight gas welding, and the dissimilar steel welded joints with good mechanical properties were obtained.The microstructure observation and compositional analysis of different regions of the welded joints showed that the micro- There exists a different type of fusion zone between the stainless steel weld and the second type of boundary line, there is Ni, Cr concentration gradient distribution in the fusion zone and the hardness is higher than the weld and base metal on both sides. The impact test tests the mechanical properties of the welded joints and obtains the polarization curves of the different parts of the joints in 1mol.L-1NaCl solution. Tensile specimens fracture occurred in the relatively low strength microalloyed steel base metal. The notch tensile strength and impact toughness are slightly lower than the duplex stainless steel base metal, but the corrosion potential slightly higher than the base metal.Micro-alloy steel heat affected zone and the parent material mechanical properties, corrosion potential slightly higher than the base metal.