材料与冶金学报2005,Vol.4Issue(2):109-109,1.
抗晶间腐蚀奥氏体不锈钢的晶界工程
Grain boundary engineering for intergranular corrosion resistant austenitic stainless steel
粉川博之1
作者信息
- 1. Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-602 Aramaki-aza-Aob, Sendai 980-8579, Japan;Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-602 Aramaki-aza-Aob, Sendai 980-8579, Japan;Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-602 Aramaki-aza-Aob, Sendai 980-8579, Japan;Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-602 Aramaki-aza-Aob, Sendai 980-8579, Japan;Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-602 Aramaki-aza-Aob, Sendai 980-8579, Japan;Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-602 Aramaki-aza-Aob, Sendai 980-8579, Japan;Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-602 Aramaki-aza-Aob, Sendai 980-8579, Japan
- 折叠
摘要
Abstract
Sensitization by chromium depletion due to chromium carbide precipitation at grain boundaries in austenitic stainless steels can not be prevented perfectly only by previous conventional techniques, such as reduction of carbon content, stabilization-treatment, local solution-heat-treatment, etc. Recent studies on grain boundary structure have revealed that the sensitization depends strongly on grain boundary character and atomic structure, and that low energy grain boundaries such as coincidence-site-lattice (CSL) boundaries have strong resistance to intergranular corrosion. The concept of 'grain boundary design and control' has been developed as grain boundary engineering (GBE). GBEed materials are characterized by high frequencies of CSL boundaries which are resistant to intergranular deterioration of materials, such as intergranular corrosion. A thermomechanical treatment was tried to improve the resistance to the sensitization by GBE. A type 304 austenitic stainless steel was cold-rolled and solution-heat-treated, and then sensitization-heat-treated. The grain boundary character distribution was examined by orientation imaging microscopy (OIM). The intergranular corrosion resistance was evaluated by electrochemical potentiokinetic reactivation (EPR) and ferric sulfate-sulfuric acid tests. The sensitivity to intergranular corrosion was reduced by the thermomechanical treatment and indicated a minimum at a small roll-reduction. The frequency of CSL boundaries indicated a maximum at the small reduction. The ferric sulfate-sulfuric acid test showed much smaller corrosion rate in the thermomechanical-treated specimen than in the base material. A high density of annealing twins were observed in the thermomechanical-treated specimen. The results suggest that the therrmomechanical treatment can introduce low energy segments in the grain boundary network by annealing twins and can arrest the percolation of intergranular corrosion from the surface. The effects of carbon content and other minor elements on optimization in grain boundary character distribution (GBCD) and thermomechanical parameters were also examined during GBE.关键词
Austenitic stainless steel/Grain boundary engineering/corrosion resistantKey words
Austenitic stainless steel/Grain boundary engineering/corrosion resistant分类
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粉川博之..抗晶间腐蚀奥氏体不锈钢的晶界工程[J].材料与冶金学报,2005,4(2):109-109,1.