Dependence of corrosion resistance on grain boundary characteristics in a high nitrogen CrMn austenitic stainless steel
来源期刊:JOURNAL OF MATERIALS SCIENCE TECHNOLOG2017年第12期
论文作者:Jianjun Qi Boyuan Huang Zhenhua Wang Hui Ding Junliang Xi Wantang Fu
文章页码:1621 - 1628
摘 要:Processing schedules for grain boundary engineering involving different types of cold deformation(tension, compression, and rolling) and annealing were designed and carried out for 18Mn18Cr0.6N high nitrogen austenitic stainless steel. The grain boundary characteristic distribution was obtained and characterized by electron backscatter diffraction(EBSD) analysis. The corrosion resistance of the specimens with different grain boundary characteristic distribution was examined by using potentiodynamic polarization test. The corrosion behavior of different types of boundaries after sensitization was also studied.The fraction of low-∑ boundaries decreased with increasing strain, and it was insensitive to the type of cold deformation when the engineering strain was lower than 20%. At the strain of 30%, the largest and smallest fractions of low-∑ boundaries were achieved in cold-tensioned and rolled specimens, respectively. The fraction of low-∑ boundaries increased exponentially with the increase of grain size. The proportion of low-∑ angle grain boundaries increased with decreasing grain size. Increasing the fraction of low-∑ boundaries could improve the pitting corrosion resistance for the steels with the same grain size.After sensitization, the relative corrosion resistances of low-∑ angle grain boundaries, ∑3 boundaries, and ∑9 boundaries were 100%, 95%, and 25%, respectively, while ∑27 boundaries, other low-∑ boundaries and random high-angle grain boundaries had no resistance to corrosion.
Jianjun Qi1,Boyuan Huang2,Zhenhua Wang1,3,Hui Ding4,Junliang Xi4,Wantang Fu1
1. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University2. School of Materials Science and Engineering, Southwest Petroleum University3. School of Mechanical Engineering, Yanshan University4. Hesteel Group Shisteel Company
摘 要:Processing schedules for grain boundary engineering involving different types of cold deformation(tension, compression, and rolling) and annealing were designed and carried out for 18Mn18Cr0.6N high nitrogen austenitic stainless steel. The grain boundary characteristic distribution was obtained and characterized by electron backscatter diffraction(EBSD) analysis. The corrosion resistance of the specimens with different grain boundary characteristic distribution was examined by using potentiodynamic polarization test. The corrosion behavior of different types of boundaries after sensitization was also studied.The fraction of low-∑ boundaries decreased with increasing strain, and it was insensitive to the type of cold deformation when the engineering strain was lower than 20%. At the strain of 30%, the largest and smallest fractions of low-∑ boundaries were achieved in cold-tensioned and rolled specimens, respectively. The fraction of low-∑ boundaries increased exponentially with the increase of grain size. The proportion of low-∑ angle grain boundaries increased with decreasing grain size. Increasing the fraction of low-∑ boundaries could improve the pitting corrosion resistance for the steels with the same grain size.After sensitization, the relative corrosion resistances of low-∑ angle grain boundaries, ∑3 boundaries, and ∑9 boundaries were 100%, 95%, and 25%, respectively, while ∑27 boundaries, other low-∑ boundaries and random high-angle grain boundaries had no resistance to corrosion.
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