Ni对304不锈钢焊接接头耐蚀性能的影响

EFFECT OF NICKEL ON CORROSION RESISTANCE OF TYPE 304 STAINLESS STEELS WELDED JOINTS

采用电化学方法和浸泡实验 ,研究了Ni对 30 4不锈钢焊接接头的均匀腐蚀、小孔腐蚀、晶间腐蚀和应力腐蚀破裂等性能的影响 .发现Ni的加入 ,可减少均匀腐蚀率、活化状态时的晶间腐蚀率和提高孔蚀电位Eb值 ,抑制阳极活性溶解 .然而加剧钝化状态时的晶间腐蚀倾向 ,并对应力腐蚀无改善作用 .

Effect of additions of 7.02～11.98 percent nickel alone on the corrosion resistance of type 304 stainless steels TIG welded joints was evaluated by electrochemical measurement and immersion tests. It was demonstrated that the additions of nickel not only decreased the general corrosion rate, increased both the E b value and resistance of intergranular corrosion in active state , but also prohibited the anodic active dissolution owing to the combined effect of chronium and nickel, which strengthed the stability of film. However, the additions promoted the intergranular corrosion trend in passive state and had no improvement on SCC, for the amount of 7.02～11.98 percent nickel located in sensitive region of SCC.