Please wait a minute...
Just Accepted | Current Issue | Archive | Featured Articles | Special Issue | Most Read | Most Downloaded | Most Cited
Acta Metall Sin  2016, Vol. 52 Issue (7): 769-777    DOI: 10.11900/0412.1961.2015.00532
Orginal Article Current Issue | Archive | Adv Search |
EFFECT OF TiN PRECIPITATES ON SOLIDIFICATION MICROSTRUCTURE OF MEDIUM CARBON Cr-Mo WEAR RESISTANT STEEL
Wenying GUO1,2,Xiaoqiang HU2(),Xiaoping MA2,Dianzhong LI2
1 School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230022, China
2 Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
Cite this article: 

Wenying GUO,Xiaoqiang HU,Xiaoping MA,Dianzhong LI. EFFECT OF TiN PRECIPITATES ON SOLIDIFICATION MICROSTRUCTURE OF MEDIUM CARBON Cr-Mo WEAR RESISTANT STEEL. Acta Metall Sin, 2016, 52(7): 769-777.

Download:  HTML  PDF(1165KB) 
Export:  BibTeX | EndNote (RIS)      
Abstract  

As an important type of wear-resistant material, the low-alloyed medium carbon wear resistant steel has been widely used in mining, power and metallurgical industries due to its low cost and excellent mechanical properties. However, the coarse as-cast microstructure tends to form in large wear resistant castings because of the long solidification time. As a result, spalling wear resulting from the preferential initiation and propagation of cracks along interdendrite will occur during service process, which severely degrades the wear resistance and service life. In this work, Ti is added to improve the mechanical properties of medium carbon Cr-Mo wear resistant steel. The precipitation behavior of TiN in the solidification process and its effect on the solidification microstructure were investigated by thermodynamic calculation, constant temperature solidification experiment at solid-liquid two phase region and continuous cooling solidification experiment by using OM, SEM, EDS and EPMA. The results show that TiN precipitation temperature gradually increases at solid-liquid two-phase region with the increase of contents of Ti and N. TiN precipitates directly in the liquid region when Ti and N contents (mass fraction) are 0.090% and 0.014%, respectively. Holding at different temperatures of solid-liquid two-phase region, a very small amount of TiN precipitates are present within the dendritic arm, and a large number of TiN precipitates are present at the interdendritic positions and frontiers of dendrites. After quenching, in the remaining liquid most of TiN are present at the boundaries of equiaxed grain and a little amount of TiN stay within the equiaxed grain. During the continuous cooling solidification, TiN precipitation temperature is the main factor affecting the refinement of solidification microstructure. With the increase of Ti content, TiN precipitation temperature increases. At the same time, the actual solidification temperature of liquid steel rises, the solidification temperature range broadens and the local solidification time extends, which results in the increase of secondary dendrite arm spacing. When Ti content exceeds 0.066%, TiN precipitation temperature is near or above the liquidus line. The actual solidification temperature of liquid steel remains unchanged. Therefore, the secondary dendrite arm spacing becomes stable.
Key words:  wear-resistant steel      TiN precipitate      solidification microstructure      secondary dendrite arm spacing     
Received:  15 October 2015     
Fund: Supported by National Natural Science Foundation of China (No.51301175)
Service
E-mail this article
Add to citation manager
E-mail Alert
RSS
（）
Articles by authors
Wenying GUO
Xiaoqiang HU
Xiaoping MA
Dianzhong LI

URL: 

https://www.ams.org.cn/EN/10.11900/0412.1961.2015.00532     OR     https://www.ams.org.cn/EN/Y2016/V52/I7/769

Fig.1  Schematic of constant temperature (a) and continuous cooling (b) solidification processes (TL—liquidus temperature, TS—solidus temperature, W.Q.—water quenching, F.C.—furnace cooling)
Sample C Si Mn P S Cr Mo Cu Ni Ti N Fe
J0 0.35 0.69 1.04 0.009 0.003 2.25 0.31 0.27 0.27 0.090 0.014 Bal.
J1 0.36 0.71 1.02 0.008 0.006 2.24 0.28 0.25 0.26 0.066 0.014 Bal.
J2 0.34 0.72 1.00 0.007 0.006 2.23 0.27 0.25 0.26 0.041 0.011 Bal.
J3 0.35 0.72 1.00 0.006 0.006 2.25 0.30 0.25 0.26 0.021 0.010 Bal.
J4 0.34 0.70 1.02 0.006 0.006 2.40 0.28 0.25 0.28 0 0.011 Bal.
Table1  Chemical composition of samples
Fig.2  Mass fraction of phases (a) and TiN (b) as a function of temperature in experimental steels at thermodynamic equilibrium state (L—liquid phase)
Sample Mass fraction
of Ti / %		 Mass fraction
of N / %		 TiN precipitation
temperature / ℃		 Fraction of
solidification
J0 0.090 0.014 1500 0
J1 0.066 0.014 1483 0.10
J2 0.041 0.011 1471 0.50
J3 0.021 0.010 1451 0.80
Table 2  Precipitation parameters of TiN in samples
Fig.3  OM images of solidification microstructures of J2 steel after holding at 1510 ℃ (a), 1480 ℃ (b), 1450 ℃ (c) and 1410 ℃ (d) for 20 min followed by water quenching
Fig.4  SEM image of TiN precipitates (a) and EDS analysis of TiN (b), Al2O3 (c) and Ti(C, N) (d) in J2 steel after holding at 1450 ℃ for 20 min
Fig.5  SEM images (a, c) and EPMA analysis (b, d) of TiN precipitate in interdendritic (a, b) and within dendrite frontier and residual liquid (c, d) in J2 steel after holding at 1450 ℃ for 20 min
Fig.6  Statistical results for mass fraction of TiN in solidification microstructure of J2 steel after holding at 1450 ℃ for 20 min (A—within dendrite, B—interdendritic, C—dendrite frontier, D—equiaxed grain boundary, E—within equiaxed grain)
Fig.7  Solidification microstructures of J0 (a), J1 (b) and J4 (c) steels continuously cooled to 1425 ℃ at cooling rate of 2.83 ℃/min
Fig.8  Effect of Ti contents on secondary dendrite arm spacing of experimental steels continuously cooled to 1350 ℃ at cooling rate of 2.83 ℃/min
[1] Deng X T, Wang Z D, Han Y, Zhao H, Wang G D.J Iron Steel Res Int, 2014; 21(1): 98
[2] Gahr K H Z.Tribol Int, 1998; 31: 587
[3] Melloy G F, Summon P R, Podgursky P P.Mater Trans, 1973; 4: 2279
[4] Kapadia B M, Brown R M, Murphy W J.Trans Met Soc AIME, 1968; 242: 1689
[5] Shen Y L, Hansen S S.Metall Mater Trans, 1997; 28A: 2027
[6] Wang C, Gao H Y, Dai Y B, Ruan X M, Wang J, Sun B D.Metall Mater Trans, 2010; 41A: 1616
[7] Bramfitt B L.Metall Trans, 1970; 1: 1987
[8] Shi C X, Cheng G G, Li Z J, Zhao P.J Iron Steel Res Int, 2008; 15(3): 57
[9] Poole W, Mitchell A, Weinberg F.High Temp Mater Proc, 1997; 16: 173
[10] Pan N, Song B, Zhai Q J, Wen B.J Univ Sci Technol Beijing, 2010; 32: 179
[10] (潘宁, 宋波, 翟启杰, 文彬. 北京科技大学学报, 2010; 32: 179)
[11] Sasaki M, Ohsasa K, Kudoh M, Matsuura K.ISIJ Int, 2008; 48: 340
[12] Ohno M, Matsuura K.ISIJ Int, 2008; 48: 1373
[13] Sasaki M, Matsuura K, Ohsasa K, Ohno M.ISIJ Int, 2009; 49: 1367
[14] Sasaki M, Matsuura K, Ohsasa K, Ohno M.ISIJ Int, 2009; 49: 1362
[15] Fu J, Zhu J, Di L, Tong F S, Liu D L, Wang Y L.Acta Metall Sin, 2000; 36: 801
[15] (傅杰, 朱剑, 迪林, 佟福生, 柳得橹, 王元立. 金属学报, 2000; 36: 801)
[16] Yang X, Cheng G G, Wang M L, Li Y L, Wang Y G, Zhao P. J Univ Sci Technol Beijing (Engl Lett), 2003; 10: 24
[17] Nagata M T, Speer J G, Matlock D K.Metall Mater Trans, 2002; 33A: 3099
[18] Cheng G G, Zhu X X, Peng Y F, Wang Y G, Zhao P.J Univ Sci Technol Beijing, 2002; 24: 273
[18] (成国光, 朱晓霞, 彭岩峰, 王玉钢, 赵沛. 北京科技大学学报, 2002; 24: 273)
[19] Shi X F, Cheng G G.Steel Making, 2008; 24(4): 36
[19] (施晓芳, 成国光. 炼钢, 2008; 24(4): 36)
[20] Pagounis E, Lindroos V K.Mater Sci Eng, 1998; A246: 221
[21] Yan W, Shan Y Y, Yang K.Metall Mater Trans, 2006; 37A: 2147
[22] Du J, Strangwood M, Davis C L. J Mater Sci Technol, 2012; 28: 878
[23] Yong Q L.Secondary Phases in Steel. Beijing: Metallurgical Industry Press, 2006: 28
[23] (雍岐龙. 钢铁材料中的第二相. 北京: 冶金工业出版社, 2006: 28)
[24] Cui Z Q, Tan Y C.Metallographic and Thermal Treatment. 2nd Ed., Beijing: China Machine Press, 2007: 37
[24] (崔忠圻, 覃耀春. 金属学与热处理. 第二版, 北京: 机械工业出版社, 2007: 37)
[25] Kurz W, Fisher D J.Fundamentals of Solidification. 4th Ed., Aedermannsdorf: Trans Tech Publications Ltd, 1998: 85
[26] Han Q Y, Hu H Q. J Univ Sci Technol Beijing, 1985; (1): 1
[26] (韩青有, 胡汉起. 北京科技大学学报, 1985; (1): 1)
[27] Pierer R, Bernhard C. J Mater Sci, 2008; 43: 6938
[28] Paliwal M, Kang D H, Essadiqi E, Jung I H.Adv Mater Res, 2012; 409: 362
[1] WU Guohua, TONG Xin, JIANG Rui, DING Wenjiang. Grain Refinement of As-Cast Mg-RE Alloys: Research Progress and Future Prospect[J]. 金属学报, 2022, 58(4): 385-399.
[2] HAN Ruyang, YANG Gengwei, SUN Xinjun, ZHAO Gang, LIANG Xiaokai, ZHU Xiaoxiang. Austenite Grain Growth Behavior of Vanadium Microalloying Medium Manganese Martensitic Wear-Resistant Steel[J]. 金属学报, 2022, 58(12): 1589-1599.
[3] ZHENG Qiuju, YE Zhongfei, JIANG Hongxiang, LU Ming, ZHANG Lili, ZHAO Jiuzhou. Effect of Micro-Alloying Element La on Solidification Microstructure and Mechanical Properties of Hypoeutectic Al-Si Alloys[J]. 金属学报, 2021, 57(1): 103-110.
[4] SUN Xinjun,LIU Luojin,LIANG Xiaokai,XU Shuai,YONG Qilong. TiC Precipitation Behavior and Its Effect on Abrasion Resistance of High Titanium Wear-Resistant Steel[J]. 金属学报, 2020, 56(4): 661-672.
[5] DENG Congkun,JIANG Hongxiang,ZHAO Jiuzhou,HE Jie,ZHAO Lei. Study on the Solidification of Ag-Ni Monotectic Alloy[J]. 金属学报, 2020, 56(2): 212-220.
[6] WU Xiang,ZUO Xiurong,ZHAO Weiwei,WANG Zhongyang. Mechanism of TiN Fracture During the Tensile Process of NM500 Wear-Resistant Steel[J]. 金属学报, 2020, 56(2): 129-136.
[7] XU Shuai, SUN Xinjun, LIANG Xiaokai, LIU Jun, YONG Qilong. Effect of Hot Rolling Deformation on Microstructure and Mechanical Properties of a High-Ti Wear-Resistant Steel[J]. 金属学报, 2020, 56(12): 1581-1591.
[8] Guohua WU, Yushi CHEN, Wenjiang DING. Current Research and Future Prospect on Microstructures Controlling of High Performance Magnesium Alloys During Solidification[J]. 金属学报, 2018, 54(5): 637-646.
[9] Qing LI,Zixing WANG,Shuyuan XIE. Research on the Development of Mathematical Model of the Whole Process of Electroslag Remelting and the Process Simulation[J]. 金属学报, 2017, 53(4): 494-504.
[10] Qian SUN,Hongxiang JIANG,Jiuzhou ZHAO. EFFECT OF MICRO-ALLOYING ELEMENT Bi ON SOLIDIFICATION AND MICROSTRUCTURE OF Al-Pb ALLOY[J]. 金属学报, 2016, 52(4): 497-504.
[11] Rui CHEN, Qingyan XU, Qinfang WU, Huiting GUO, Baicheng LIU. NUCLEATION MODEL AND DENDRITE GROWTH SIMULATION IN SOLIDIFICATON PROCESS OF Al-7Si-Mg ALLOY[J]. 金属学报, 2015, 51(6): 733-744.
[12] YAN Yuncheng, DING Hongsheng, SONG Jinxia, KANG Yongwang, CHEN Ruirun, GUO Jingjie. EFFECT OF PROCESSING PARAMETERS ON SOLID-LIQUID INTERFACE OF Nb-Si BASE ALLOY FABRICATED BY ELECTROMAGNETIC COLD CRUCIBLE DIRECTIONAL SOLIDIFICATION[J]. 金属学报, 2014, 50(9): 1039-1045.
[13] ZHOU Xuefeng, FANG Feng, TU Yiyou, JIANG Jianqing, XU Huixia, ZHU Wanglong. EFFECT OF ALUMINUM ON THE SOLIDIFICATION MICROSTRUCTURE OF M2 HIGH SPEED STEEL[J]. 金属学报, 2014, 50(7): 769-776.
[14] ZHAO Jiuzhou, LI Lu, ZHANG Xianfei. DEVELOPMENT OF CELLULAR AUTOMATON MODELS AND SIMULATION METHODS FOR SOLIDIFICATION OF ALLOYS[J]. 金属学报, 2014, 50(6): 641-651.
[15] JIA Peng, WANG Engang, LU Hui, HE Jicheng. EFFECT OF ELECTROMAGNETIC FIELD ON MICRO-STRUCTURE AND MECHANICAL PROPERTY FOR INCONEL 625 SUPERALLOY[J]. 金属学报, 2013, 49(12): 1573-1580.
No Suggested Reading articles found!

Copyright © 2017 Acta Metallurgica Sinica, All Rights Reserved.
Editorial Office: Acta Metallurgica Sinica, 72 Wenhua Rd., Shenyang 110016, China
Tel: +86- 024-23971286, Fax: +86-024-23843760 　E-mail: jsxb@imr.ac.cn
Powered by Beijing Magtech