Effect of Post-weld Heat Treatment on the Microstructure and Corrosion Resistance of Deposited Metal of a HighChromium Nickel-Based Alloy
来源期刊：Acta Metallurgica Sinica2016年第12期
论文作者：Xin-Jie Di Xiao-Qian Liu Cui-Xin Chen Bao-Sen Wang Xiao-Jiang Guo
文章页码：1136 - 1143
摘 要：The evolution of Cr23C6 carbides in the deposited metal（DM） of a high-chromium nickel-based alloy was investigated after the post-weld heat treatment（PWHT） at 650,750,850,and 950 ℃,respectively.With the increase in temperature,the morphology of the Cr23C6 carbides at the grain boundaries was transformed from the continuous lamellarlike to the semi-continuous rod-like and then to the discontinuous granular.Besides,the needle-like Cr23C6 carbides precipitated from γ matrix after PWHT at 850 ℃.The coarsening kinetics of the needle-like Cr23C6 carbides obeyed the Lifshitz-Slyozov-Wagner law with the growth speed of 4.93 μm3/h in length and 5.56 × 10-3 μm3/h in width.Moreover,the ratio of the carbide length to width increased rapidly at first and then flattened as the holding time increased to 850 ℃.The results of electrochemical corrosion experiment indicated that the needled-like Cr23C6 carbides impaired the corrosion resistance of DM due to the formation of chromium depletion around the carbides.
Xin-Jie Di1，Xiao-Qian Liu1，Cui-Xin Chen2，Bao-Sen Wang3，Xiao-Jiang Guo4
1. School of Materials Science and Engineering,Tianjin University2. School of Materials Science and Engineering,Hebei University of Technology3. Baosteel Research Institute,Baoshan Iron & Steel Co.,Ltd.4. National Engineering Laboratory of Transportation Safety of Oil & Gas Pipeline
摘 要：The evolution of Cr23C6 carbides in the deposited metal（DM） of a high-chromium nickel-based alloy was investigated after the post-weld heat treatment（PWHT） at 650,750,850,and 950 ℃,respectively.With the increase in temperature,the morphology of the Cr23C6 carbides at the grain boundaries was transformed from the continuous lamellarlike to the semi-continuous rod-like and then to the discontinuous granular.Besides,the needle-like Cr23C6 carbides precipitated from γ matrix after PWHT at 850 ℃.The coarsening kinetics of the needle-like Cr23C6 carbides obeyed the Lifshitz-Slyozov-Wagner law with the growth speed of 4.93 μm3/h in length and 5.56 × 10-3 μm3/h in width.Moreover,the ratio of the carbide length to width increased rapidly at first and then flattened as the holding time increased to 850 ℃.The results of electrochemical corrosion experiment indicated that the needled-like Cr23C6 carbides impaired the corrosion resistance of DM due to the formation of chromium depletion around the carbides.
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