Effect of Thermal Processing on the "Gold Dust" Defect of 430 Ferritic Stainless Steel
SHAO Ze-bin1,2, CHEN Hai-tao2, LANG Yu-ping2, ZHU Xin-kun1
1. Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China;
2. Institute of Structure Materials, Central Iron and Steel Research Institute, Beijing 100081, China
Abstract：The relationship between the intergranular corrosion and "gold dust" defects on surfaces of 430 ferritic stainless steel was investigated. On the basis of the different hot rolling tests performed on Gleeble 3800 thermal mechanical simulation and simulated coiling test after deformation, a study was conducted in order to determine the effect of thermal processing on the intergranular corrosion of 430 ferritic stainless steel. The DL-EPR was introduced to measure the susceptibility to intergranular corrosion.The results showed that the 430 ferritic stainless steel sensitization happened in the process of hot rolling, then conduce intergranular corrosion during the pickling, eventually produced the "gold dust" defects after cold rolling. It is found that the intergranular corrosion sensitization could be effectively prevented with a combination of final rapid cooling (water cooling) at the final deformation temperature of 900-950℃.By the analysis of simulated coiling test results, the intergranular corrosion susceptibility of 430 ferritic stainless steel can be further avoided and eliminated by a treatment of 650-800℃.
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