Hot Deformation Behavior of a New 9%Cr Heat Resistant Steel G115  

作　　者：YAN Peng LIU Zheng-dong LIU Wei BAO Han-sheng WENG Yu-qing 

机构地区：[1]Key Laboratory of Advanced Material of Ministry of Eclucation of China,School of Materials Science and Engineering,Tsinghua University [2]Institute for Special Steels,China Iron and Steel Research Institute

出　　处：《Journal of Iron and Steel Research International》2013年第9期73-79,共7页

基　　金：Sponsored by National Basic Research Program of China(2010CB630804);National High Technology Research and Development Program of China(2012AA03A501)

摘　　要：The hot deformation behavior of a new heat resistant steel Gl15 designed for 650 ℃ ultra-supercritical （USC） power plants was experimentally studied. Hot compression test was carried out in the temperature range of 900-1 200 ℃ and the strain rate range of 0.1-20 s i by using Gleeble 3800 thermal-mechanical simulator, and the corresponding flow curves were obtained. Experimental results show that the flow stress increases with the decrease of deformation temperature and the increase of strain rate. The hot deformation activation energy of G115 steel was determined to be 494 kJ/mol and the constitutive equation was also obtained. For convenience of the practical applica-tion, a good approximate equation was obtained for calculating the peak stress values of Gl15 steel under different deformation conditions. At the strain value of 0.9, natural logarithm of the critical Zener Hollomon parameter Zc of Gl15 steel was determined to be in the scope of 49.67 and 50.65, above which there will be no dynamic recrystalliza-tion （DRX）. And natural logarithm of the critical Zener-Hollomon parameter Zc of Gl15 steel was determined to be in the scopes of 45.58 and 46.27, below which full DRX may occur. Then, the status diagram of dynamic micro structures of G115 steel was established. In addition, the strain rate sensitivity of Gl15 steel is not constant during the test temperature range and it increases linearly from 900 to 1 200 ℃. Therefore, hot deformation at higher tem- peratures would obtain better workability.The hot deformation behavior of a new heat resistant steel Gl15 designed for 650 ℃ ultra-supercritical （USC） power plants was experimentally studied. Hot compression test was carried out in the temperature range of 900-1 200 ℃ and the strain rate range of 0.1-20 s i by using Gleeble 3800 thermal-mechanical simulator, and the corresponding flow curves were obtained. Experimental results show that the flow stress increases with the decrease of deformation temperature and the increase of strain rate. The hot deformation activation energy of G115 steel was determined to be 494 kJ/mol and the constitutive equation was also obtained. For convenience of the practical applica-tion, a good approximate equation was obtained for calculating the peak stress values of Gl15 steel under different deformation conditions. At the strain value of 0.9, natural logarithm of the critical Zener Hollomon parameter Zc of Gl15 steel was determined to be in the scope of 49.67 and 50.65, above which there will be no dynamic recrystalliza-tion （DRX）. And natural logarithm of the critical Zener-Hollomon parameter Zc of Gl15 steel was determined to be in the scopes of 45.58 and 46.27, below which full DRX may occur. Then, the status diagram of dynamic micro structures of G115 steel was established. In addition, the strain rate sensitivity of Gl15 steel is not constant during the test temperature range and it increases linearly from 900 to 1 200 ℃. Therefore, hot deformation at higher tem- peratures would obtain better workability.

关 键 词：heat resistant steel G115 hot deformation dynamic recrystallization constitutive equation Zener Hol-lomon parameter 

分 类 号：TG142.73[一般工业技术—材料科学与工程] TQ323.4[金属学及工艺—金属材料]