|
|
EFFECT OF Nb ON SEGREGATION, PRIMARY CARBIDES AND TOUGHNESS OF H13 STEEL |
WANG Ming1,2(), MA Dangshen2, LIU Zhentian3, ZHOU Jian2, CHI Hongxiao2, DAI Jianqing1 |
1 College of Materials Science and Engineering, Kunming University of Science and Technology,Kunming 650093 2 Institute for Special Steel, Central Iron & Steel Research Institute, Beijing 100081 3 Fushun Special Steel Co., Ltd, Fushun 113001 |
|
Cite this article:
WANG Ming, MA Dangshen, LIU Zhentian, ZHOU Jian, CHI Hongxiao, DAI Jianqing. EFFECT OF Nb ON SEGREGATION, PRIMARY CARBIDES AND TOUGHNESS OF H13 STEEL. Acta Metall Sin, 2014, 50(3): 285-293.
|
Abstract Mandrel is an important tool for thermal deformation of the seamless steel tube rolling unit. It requires high heat resistance and toughness due to its application in the harsh environment. H13 steel is commonly used as mandrel materials with excellent comprehensive performance. It is reported that addition of carbide-forming elements, such as Nb, Ti, or Zr, especially the Nb element, can break the dendritic microstructure and refine the cast structure of H13 steel. In addition, Nb can act as a strong carbide-forming element to favor the formation of MC carbide. This stable carbide has low solubility and does not dissolve in austenite even at high temperature, and hence fines austenite grain by pinning effect of carbide on grain boundary. As the stable NbC has stronger ability to improve the fatigue resistance and abrasion resistance than Mo6C and VC, the mandrel steel can be produced by the method of Nb addition. It has been reported that the addition of Nb in H13 can successfully increase heat resistance. Nb element dissolves into the matrix after quenching and tempering, and precipitates in the form of NbC after heat preservation for a long time, and eventually improves the resistance of material to temper softening. However, it has not been widely applied in the production because the primary carbides of NbC can seriously deteriorate toughness of steel. The purpose of the work is to analyze the effect of addition of 0.06%Nb (mass fraction) on segregation, primary carbides and toughness of large size H13 mandrel steel. The different segregation, primary carbides, structure between large size H13 and H13-Nb mandrel were investigated by employing methods of OM, SEM, EDS and EBSD, and the mechanical properties including the hardness and impact toughness were measured at room temperature. The results show that addition of 0.06%Nb aggravates segregation compared with H13. Nb increases the precipitation temperature of MC-primary carbides, and changes the type of MC-primary carbides from mainly VC to mainly (Nb, V)C which easily induces gravitational segregation of H13-Nb. The severe segregation leads to unfavorable structure of the large and nonhomogeneous effective grain size (EGS) of annealed H13-Nb, and the primary carbides do not decrease or change significantly after quenching and tempering. In the impact test, the zone of the chain-shaped carbides gathering is prone to cracking and generates horizontal stripes, resulting in low toughness.
|
Received: 03 August 2013
|
|
Fund: Supported by National Key Technologies R&D Program of China (No.2007BAE510B04) |
[1] |
Xie Z Y. Spec Steel Technol, 2010; 16(1): 11
|
|
(谢珍勇. 特钢技术, 2010; 16(1): 11)
|
[2] |
Akiyama M, Tsubounchi K, Tsumure M. J Mater, 2000; 214(2): 61
|
[3] |
Wang S J. Steel Pipe, 1992; 27(1): 45
|
|
(王士俊. 钢管, 1992; 27(1): 45)
|
[4] |
Wang X J, Xu M G, Chen Q L. Shanghai Met, 1998; 20(2): 8
|
|
(王小军, 徐明纲, 陈秋龙. 上海金属, 1998; 20(2): 8)
|
[5] |
Dutta B, Sellars C M. Mater Sci Technol, 1987; 3: 197
|
[6] |
Lu Z, Faulkner R G, Riddle N, Martino F D, Yang K. J Nucl Mater, 2009; 30: 445
|
[7] |
Liu J H, Ma D S, Zhang Z P, Wu L Z, Chen Z Z, Chi H X. Spec Steel, 2008; 29(6): 55
|
|
(刘建华, 马党参, 张占普, 吴立志, 陈再枝, 迟宏宵. 特殊钢, 2008; 29(6): 55)
|
[8] |
Elias C N, Da Costa Viana C S. Mater Sci Technol, 1992; 8: 785
|
[9] |
Hu X B, Li L, Wu X C. Heat Treat Met, 2004; 29(8): 13
|
|
(胡心彬, 李 麟, 吴晓春. 金属热处理, 2004; 29(8): 13)
|
[10] |
Chen Y W, Wu X C, Song W W. Trans Mater Heat Treat, 2010; 31(5): 75
|
|
(陈英伟, 吴晓春, 宋雯雯. 材料热处理学报, 2010; 31(5): 75)
|
[11] |
Ma D S, Zhou J, Zhang Z K, Chi H X, Chen Z Z. Iron Steel, 2010; 45(8): 80
|
|
(马党参, 周 健, 张忠侃, 迟宏宵, 陈再枝. 钢铁, 2010; 45(8): 80)
|
[12] |
Lu M H, Tian Y X, Cai H Y, Yin G H. Heat Treat Met, 2010; 35(8): 9
|
|
(陆明和, 田玉新, 蔡海燕, 殷光虹. 金属热处理, 2010; 35(8): 9)
|
[13] |
Chi H X, Ma D S, Liu J H, Chen Z Z, Yong Q L. Acta Metall Sin, 2010; 46: 206
|
|
(迟宏宵, 马党参, 刘建华, 陈再枝, 雍岐龙. 金属学报, 2010; 46: 206)
|
[14] |
Chen Z Z,Lan D N. Die and Mould Steel Manual. Beijing: Metallurgical Industry Press, 2002: 378
|
|
(陈再枝,蓝德年. 模具钢手册. 北京: 冶金工业出版社, 2002: 378)
|
[15] |
Zhou J, Ma D S, Liu B S, Kang A J, Li X Y. Res Iron Steel, 2012; (4): 47
|
|
(周 健, 马党参, 刘宝石, 康爱军, 李向阳. 钢铁研究, 2012; (4): 47)
|
[16] |
Miao C L, Shang C J, Wang X M, Zhang L F. Acta Metall Sin, 2010; 46: 541
|
|
(缪成亮, 尚成嘉, 王学敏, 张龙飞. 金属学报, 2010; 46: 541)
|
[17] |
Wang C F. PhD Dissertation, Central Iron & Steel Research Institute, Beijing, 2008
|
|
(王春芳. 钢铁研究总院博士学位论文, 北京, 2008)
|
[18] |
Qi J J,Huang Y H,Zhang Y. Microalloyed Stee. Beijing: Metallurgical Industry Press, 2006: 37
|
|
(齐俊杰,黄运华,张 跃. 微合金化钢. 北京: 冶金工业出版社, 2006: 37)
|
[19] |
Li H Y, Hu J D, Li Y H. Trans Mater Heat Treat, 2012; 33(1): 122
|
|
(李红英, 胡继东, 李阳华. 材料热处理学报, 2012; 33(1): 122)
|
[20] |
Yong Q L. Secondary Phases in Steels. Beijing: Metallurgical Industry Press, 2006: 343
|
|
(雍岐龙. 钢铁材料中的第二相. 北京: 冶金工业出版社, 2006: 343)
|
[21] |
Hackl G. PhD Dissentation, University of Leoben, 1991
|
[22] |
Shi R X, Yang R C, Yin Y S, Zhou C H. Res Iron Steel, 2004; (2): 34
|
|
(师瑞霞, 杨瑞成, 尹衍升, 周春华. 钢铁研究, 2004; (2): 34)
|
[23] |
Mahnken R, Schneidt A, Antretter T. Int J Plasticity, 2009; 25(2): 183
|
[24] |
Dong J X, Zhang M C, Zeng Y P. J Univ Sci Technol Beijing, 2005; 27: 197
|
|
(董建新, 张麦仓, 曾燕屏. 北京科技大学学报, 2005; 27: 197)
|
[25] |
Liu D R, Sang B G, Kang X H, Li D Z. Acta Phys Sin, 2009; 58(6): 104
|
|
(刘东戎, 桑宝光, 康秀红, 李殿中. 物理学报, 2009; 58(6): 104)
|
No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
|
Shared |
|
|
|
|
|
Discussed |
|
|
|
|