奥氏体不锈钢表面改性层耐蚀性实验研究　Ⅱ.3%NaCl溶液中E-pH图  

CORROSION RESISTANCE OF MODIFIED SURFACE LAYER ON AUSTENITIC STAINLESS STEEL Ⅱ. E-PH Diagram in 3% NaCl Solution

作　　者：雷明凯[1] 朱雪梅[2] 

机构地区：[1]大连理工大学材料工程系,大连116024 [2]大连铁道学院材料科学与工程系,大连116028

出　　处：《金属学报》1999年第10期1085-1089,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金!59771060

摘　　要：等离子体源离子渗氮1Cr18Ni9Ti不锈钢获得的峰值氮含量为32％，深度为13μm的单相高氮面心相（γN）表面改性层，与原始不锈钢相比较，在3％NaCl溶液中的E-pH图具有扩大的热力学稳定区、完全钝化区，以及缩小的不完全钝化区、孔蚀区．在pH＜0．4时，γN相改性层发生与原始不锈钢相同的均匀腐蚀；在pH＝0．4—3时，γN相改性层孔蚀击穿电位增高，耐孔蚀性能改善；在pH=4─11时，γN相改性层完全不发生扎蚀，耐孔蚀性能显著优于原始不锈钢；在pH＞11时，γN相改性层与原始不锈钢相同，均不发生孔蚀．The potential E-pH diagram of the 13 pm-thick γN phase layer with a peak of nitrogenconceatration of 32%, which formed on the 1Cr18Ni9Ti austenitic stainless steel nitrided at 380 ℃ byplasma source ion nitriding, has been obtained in 3% NaCl solutions。 The diagram has the extendedimmunity and perfect passivity zones and the narrowed imperfect passivity and pitting zones, comparedwith that of original stainless steel. In 3% NaCl solutions with pH<O.4, the general corrosion resistancewas observed for either the γN phase layer or the original stainless steel. With enhancing the pH from O.4to 3 the improved pitting corrosion resistance was detected for the γN phase layer due to the increase ofpitting breakdown potential. When the pH was between 4-11, no pitting corrosion was observed for theγN phase layer, whose corrosion resistance was markedly better than that of original stainless steel. Afterincreasing the pH over 11, both the γN phase layer and the original stainless steel did not produce thepitting corrosion.

关 键 词：奥氏体不锈钢 离子渗氮 表面改性 孔蚀 E-pH图 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TG174.4[金属学及工艺—金属材料]