HOT DEFORMATION AT ELEVATED TEMPERATURE AND RECRYSTALLIZATION BEHAVIOR OF A HIGH MANGANESE AUSTENITIC TWIP STEEL
Xiaoyun YUAN,Liqing CHEN()
State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819
Cite this article:
Xiaoyun YUAN, Liqing CHEN. HOT DEFORMATION AT ELEVATED TEMPERATURE AND RECRYSTALLIZATION BEHAVIOR OF A HIGH MANGANESE AUSTENITIC TWIP STEEL. Acta Metall Sin, 2015, 51(6): 651-658.
Stainless steel is widely used in both industrial production and daily-life due to its anti-corrosion behavior. In view of the shortage in Cr and Ni resources, there has been an increasing interest in developing low-cost stainless steels for several decades. Under the frame of replacing Ni and Cr with Mn and Al, respectively, a recent study indicates that Fe-Mn-Al-C austenitic twinning-induced plasticity (TWIP) steel possesses good comprehensive properties and excellent resistance to oxidation that make it potential in partially replacing conventional austenitic stainless steels. As a viable alternative to low-cost austenitic stainless steel, a new alloy system of high-manganese low-chromium nitrogen-containing TWIP steel was developed in this study. Considering its corrosion resistance, the alloy is not completely free of chromium, yet the Cr content is relatively low. Nitrogen is added, because it is a strong austenite stabilizer that can reduce the tendency to form ferrite and deformation-induced a'- and e-martensites, thereby reducing the amount of nickel required in austenitic stainless steel. Furthermore, nitrogen is beneficial for pitting corrosion resistance. In this study, hot deformation and recrystallization behaviors of this high manganese austenitic TWIP steel were investigated by single-pass compression tests on MMS-300 thermo-mechanical simulator at temperature ranging from 1223 K to 1423 K and strain rate ranging from 0.01 s-1 to 10 s-1. Microstructure evolution during dynamic recrystallization and the correlation of microstructure change to the stress-strain response were further analyzed by using TEM and SEM equipped with EBSD. The results show that the hot deformation behavior of this steel is more sensitive to deformation rate. Dynamic recrystallization occurs during hot deformation when deformation rate is lower than 0.1 s-1, while dynamic recovery takes place at deformation rate higher than 1 s-1. The hot deformation constitutive equation of the high manganese austenitic TWIP steel was established by regression analysis. There is a close correlation between microstructure evolution and stress-strain curve during dynamic recrystallization. With the increase of strain, the grain boundary migration leads to the nucleation of recrystallization. Sub-grain boundary was also formed with increasing the strain. Dislocations climbing or slipping on the adjacent sub-grain boundary lead to the grain boundary merging, and then, new austenitic grains formed.
Fig.1 True stress-strain curves of high manganese austenitic twinning induced plasticity (TWIP) steel deformed at different temperatures and strain rates of
Fig.2 SEM images of high manganese austenitic TWIP steel deformed at 1223 K and 0.01 s-1 (b)
Fig.3 SEM images of the high manganese austenitic TWIP steel deformed at 1223 K (a), 1323 K (b) and 1423 K
Fig.4 Residual sum of squares (RSS) of n against the value of a
Fig.5 Relationships between peak stress and strain rate (a) and peak stress and temperature (b)
Fig.6 Relationship between lnZ and ln[sinh(as)]
Fig.7 EBSD maps showing grain boundary distribution of high manganese austenitic TWIP steel deformed to various strains of e=0 (a), e=0.05 (b), e=0.15 (c), e=0.25 (d), e=0.45 (e) and e=0.7 (f) under the condition of 1323 K and strain rate 0.05 s-1
Fig.8 TEM images show dynamically recrystallized microstructures of high manganese austenitic TWIP steel deformed to various strains under the condition of 1323 K and strain rate 0.05 s-1
[1]
Wang C J, Chang Y C. Mater Chem Phys, 2002; 76: 151
[2]
Gr?ssel O, Kruger L, Frommeyer G, Meyer L W. Int J Plast, 2000; 16: 1391
[3]
Brüx U, Frommeyer G, Gr?ssel O, Meyer L W, Weise A. Steel Res Int, 2002; 73: 294
[4]
Chen L Q, Zhao Y, Qin X M. Acta Metall Sin (Engl Lett), 2013; 26: 1
[5]
Chung K, Ahn K, Yoo D H, Chung K H, Seo M H. Int J Plast, 2011; 27: 52
[6]
Bouaziz O, Allain S, Scott C P, Cugy P, Barbier D. Curr Opin Solid State Mater Sci, 2011; 15: 141
[7]
Barbier D, Gey N, Allain S, Bozzolo N, Humbert M. Mater Sci Eng, 2009; A500: 196
[8]
Kibey S, Liu J B, Curtis M J, Johnson D D, Sehitoglu H. Acta Mater, 2006; 54: 2991
[9]
Huang B X, Wang X D, Rong Y H. Mater Sci Eng, 2006; A438-440: 306
[10]
Yuan X Y, Yao Y T, Chen L Q. Acta Metall Sin (Engl Lett), 2014; 27: 401
[11]
Yuan X Y, Chen L Q, Zhao Y, Di H S, Zhu F X. J Mater Process Technol, 2015; 217: 278
[12]
Ding H, Tang Z Y, Li W, Wang M, Song D. J Iron Steel Res, 2006; 13(6): 66
[13]
Chen T H, Yang J R. Mater Sci Eng, 2001; A311: 28
[14]
Zhang J Q, Di H S, Wang X Y, Cao Y, Zhang J C, Ma T J. Mater Des, 2013; 44: 354
[15]
Zheng M Y, Wu K, Liang M, Kamado S, Kojima Y. Mater Sci Eng, 2004; A372: 66
[16]
Li A B, Geng L, Zhang J, Xu H Y, Zheng Z Z, Yao C K. Mater Chem Phys, 2004; 84: 29
[17]
Venugopal S, Mannan S L, Rodriguez P. J Mater Sci, 2004; 39: 5557
[18]
Cao Y, Di H S, Zhang J C, Zhang J Q. Acta Metall Sin, 2012; 48: 1175 (曹 宇, 邸红双, 张洁岑, 张敬奇. 金属学报, 2012; 48: 1175)
[19]
Wang Z X. Controlled Rolling and Controlled Cooling. Beijing: Metallurgical Industry Press, 1988: 14 (王占学. 控制轧制与控制冷却. 北京: 冶金工业出版社, 1988:14)
[20]
McQueen H J, Ryan N D. Mater Sci Eng, 2002; A322: 43
[21]
Chen L Q, Zhao Y, Xu Q X, Liu X H. Acta Metall Sin, 2010; 46: 1215 (陈礼清, 赵 阳, 徐秋香, 刘相华. 金属学报, 2010; 46: 1215)
[22]
Medina S F, Hernadez C A. Acta Mater, 1996; 44: 137
[23]
Liu Z Y, Chen L S, Zhou M C, Liu X H, Wang G D. J Iron Steel Res, 2004; 16(1): 49 (刘战英, 陈连生, 周满春, 刘相华, 王国栋. 钢铁研究学报, 2004; 16(1): 49)
[24]
Yu J W, Liu X F, Xie J X. Acta Metall Sin, 2011; 47: 486 (余均武, 刘雪峰, 谢建新. 金属学报, 2011; 47: 486)
[25]
Yue C X, Zhang L W, Liao S L, Pei J B, Gao H J, Jia Y W, Lian X J. Mater Sci Eng, 2007; A499: 177
[26]
Fernández A I, Uranga P, López B, Rodriguez-Ibabe J M. Mater Sci Eng, 2003; A361: 367
0.01 s-1 (b)
