不锈钢焊接接头腐蚀行为研究进展

摘要

In this article, it summarized the recent research progress of stainless steels welded joints from pitting; stress corrosion and intergranular corrosion, and analyzed the corrosion behaviors and mechanisms of stainless steels welded joints. The results indicated that the primary reason for welded joints corrosion is complex temperature field and high heat input made σ phase, Cr23C6,Cr7C3 and Cr2N precipitate, and caused uneven distribution of Cr and Mo elements in structure. It pointed out that reducing heat input, increasing cooling speed, adding alloying elements and postweld heat treatment can restrain chemical compound precipitation, decrease the uneven distribution of elements to increase corrosion resistance of stainless steel welded joints.%总结了目前不锈钢焊接接头的点蚀、应力腐蚀和晶间腐蚀行为的最新研究进展，并对不锈钢焊接接头腐蚀行为及机理进行了分析。分析表明，不锈钢焊接接头腐蚀的根本原因是由于焊接复杂的温度场及较高的热输入，使不锈钢焊接接头中σ相， Cr23C6， Cr7C3和Cr2N等化合物析出，造成了组织中Cr和Mo等元素的不均匀分布。指出，减少热输入、增大冷速、加入合金元素以及焊后热处理等可以抑制化合物的析出，减少已经存在的析出相及降低元素的不均匀分布现象，从而提高不锈钢焊接接头的耐蚀能力。