【摘要】 通过变形量为78%的冷轧以及750℃退火处理10和15 min获得由不同比例的再结晶片层、纳米/超细晶片层和残留奥氏体片层构成的层状异质(HL)结构316L奥氏体不锈钢,利用电化学腐蚀试验测试其耐腐蚀性能。结果表明,具有HL结构的试样的耐腐蚀性能优于冷轧试样。这主要归因于退火过程中部分再结晶消除了冷变形组织中大部分腐蚀敏感区域,同时,纳米/超细晶和残留奥氏体中的高密度的低角度晶界具有更强的再钝化能力和耐腐蚀性能,有效抑制亚稳态点蚀坑的扩展。但随着退火时间延长,试样的再结晶程度增加、低角度晶界比例下降,减弱了对亚稳态点蚀坑扩展的抑制作用,导致耐腐蚀性能下降。更多还原

【Abstract】 The 316L austenitic stainless steel with heterogeneous lamella(HL) structure composed of different proportions of recrystallized lamellae, nano/ultrafine lamellae and retained austenite lamellae was obtained by cold rolling with a deformation of 78% and annealing at 750 ℃ for 10 min and 15 min, and its corrosion properties were tested by electrochemical corrosion experiments. The results show that the corrosion resistance of the samples with HL structure is better than that of cold rolled sample. This is mainly attributed to the partial recrystallization during the annealing, which eliminates most of the corrosion sensitive areas in the cold deformed microstructure.Additionally, the high-density low angle grain boundaries in the nano/ultrafine grain and retained austenite have stronger repassivation ability and corrosion resistance, effectively suppressing the expansion of metastable pitting. However, as the annealing time increases, the degree of recrystallization of the sample increases and the proportion of low angle grain boundaries decreases, weakening the inhibitory effect on the expansion of metastable pitting and leading to a decrease in corrosion resistance.更多还原