Microstructural evolution of a superaustenitic stainless steel during a two-step deformation process

作     者：N.Bayat G.R.Ebrahimi A.Momeni H.R.Ezatpour 

作者机构：Department of Materials and Polymer Engineering Hakim Sabzevari University Department of Materials Science and Engineering Hamedan University of Technology Faculty of Engineering Sabzevar University of New Technology 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2018年第25卷第2期

页      面：181-189页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 07[理学] 08[工学] 070205[理学-凝聚态物理] 0806[工学-冶金工程] 0708[理学-地球物理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

主　　题：superaustenitic stainless steel dynamic recrystallization static softening metadynamic recrystallization microstructural evolution Avrami kinetics equation 

摘      要：Single-and two-step hot compression experiments were carried out on 16Cr25Ni6Mo superaustenitic stainless steel in the temperature range from 950 to 1150°C and at a strain rate of 0.1 s^（-1）. In the two-step tests, the first pass was interrupted at a strain of 0.2; after an interpass time of 5, 20, 40, 60, or 80 s, the test was resumed. The progress of dynamic recrystallization at the interruption strain was less than 10%. The static softening in the interpass period increased with increasing deformation temperature and increasing interpass time. The static recrystallization was found to be responsible for fast static softening in the temperature range from 950 to 1050°C. However, the gentle static softening at 1100 and 1150°C was attributed to the combination of static and metadynamic recrystallizations. The correlation between calculated fractional softening and microstructural observations showed that approximately 30% of interpass softening could be attributed to the static recovery. The microstructural observations illustrated the formation of fine recrystallized grains at the grain boundaries at longer interpass time. The Avrami kinetics equation was used to establish a relationship between the fractional softening and the interpass period. The activation energy for static softening was determined as 276 kJ/mol.