不同补焊次数对X2CrNi12铁素体不锈钢焊接接头耐点蚀性能的影响研究

Impact of Various Addition Welding Times on the Corrosion Resistance of X2CrNi12 Ferritic Stainless Steel Welded Joints

以X2CrNi12铁素体不锈钢为研究对象,采用MAG焊进行不同次数的补焊,探讨了补焊次数对焊接接头组织及耐点蚀性能的影响。研究结果表明,一次补焊和二次补焊接头的焊缝区显微组织基本相似,主要由白色的奥氏体基体以及黑色的板条状和网状δ铁素体组成。与母材相比,焊接接头的晶粒尺寸明显增大。电化学测试结果显示,焊缝区的耐蚀性最好,其次是母材,而HAZ的耐蚀性最差。SEM观察发现,焊缝区无点蚀产生,而母材和HAZ出现了均匀分布的小点蚀坑。与一次补焊相比,二次补焊后的焊缝区耐蚀性更好。因此,二次补焊有利于提高X2CrNi12铁素体不锈钢焊接接头的耐点蚀性能。这一研究结果为根据焊接接头的电化学点蚀性能选择合适的补焊次数提供了理论依据。

This study investigates the effects of varying numbers of re-weldings on the microstructure and pitting resistance performance of X2CrNi12 ferritic stainless steel using MAG welding.The results reveal that the microstructure of the weld zone in both the first and second re-weld joints is largely similar,primarily consisting of a white austenite matrix interspersed with black plate-like and net-likeδferrite.Notably,the grain size of the welded joint significantly increases compared to the parent material.Electrochemical tests indicate that the corrosion resistance of the weld zone is superior to that of the parent material,while the HAZ exhibits the lowest corrosion resistance.Scanning Electron Microscope(SEM)observations reveal no pitting in the weld zone,whereas small pits are uniformly distributed in both the parent material and HAZ.Furthermore,the corrosion resistance of the weld zone post the second re-weld surpasses that of the first re-weld.Consequently,a second re-weld enhances the pitting resistance performance of X2CrNi12 ferritic stainless steel welded joints.These findings provide a theoretical foundation for selecting appropriate re-welding times based on the electrochemical pitting performance of the welded joint.