|
|
|
| Effects of cooling intensity on MnS growth during solidification in ultra-high sulfur medium carbon steel billet |
| LÜ Nai-bing1,2, GAO Hang3, LIU Ke1,4, LIU Bin1, XU Shi-xin1, ZHOU Jie1 |
1. Research Institute of Technology, Shougang Group Co., Ltd., Beijing 100043, China;
2. Beijing Key Laboratory of Green Recyclable Process for Iron and Steel Production Technology, Beijing 100043, China;
3. Marketing Department, Guiyang Special Steel Co., Ltd., Shougang Group, Guiyang 550005, Guizhou, China;
4. Beijing Engineering Research Center of Energy Steel, Beijing 100043, China |
|
|
|
|
Abstract Medium-carbon ultra-high sulfur free-cutting steel SAE144 is a structural steel with both mechanical properties and machinability,thus used as automotive engine sealing valves, etc. The production process is mostly converter/electric furnace→LF refining→continuous casting→wire rod hot rolling→cold drawing and machining,the market popularity has steadily increased in recent years. If the MnS inclusions in the steel are not properly controlled, problems such as failure in flaw detection, poor machinability, severe band structure, significant dissimilarity in mechanical properties, and even drawing fractures are likely to occur. MnS inclusions are mostly formed in the late stage of billet solidification and are deformed synchronously with the steel matrix during rolling. Controlling the original size of MnS in the billet has become the most critical step to control the morphology and size of MnS inclusions in hot-rolled products.In order to control MnS inclusions in hot-rolled ultra-high sulfur medium-carbon steel wire rod, the segregation of S element and generation, growth and ripening of MnS was analyzed by the billet solidification numerical simulation calculation, second phase precipitation theory and Ostwald ripening theory in 160 mm2 billet. The calculation results show that MnS is generated at the end of the solidification in cast billet when solid phase fraction fs=0.446 with the segregation ratio of S reaches 2.19. The growth process of MnS during solidification determines the diameter of MnS particles in the billet. The theoretical calculation shows that when the secondary cooling water volume is fixed to 0.6 L/kg, the MnS in the 160 mm2 billet center grows up to 30.6, 32.2 and 34.6 μm at the casting speed of 1.6, 2.1 and 2.6 m/min respectively, which is consistent with the actual test results. The key to controll the size of MnS in wire rod is to increase the cooling intensity of the secondary cooling zone and reduce the casting speed of the billet. Based on the calculation method in this paper, control range of continuous casting process parameters matching the MnS diameter in 160 mm2 billet is presented.
|
|
Received: 11 November 2021
|
|
|
|
[1] 王小红,谢兵,冯仲渝.国内外易切削钢的现状和研究进展[J].特殊钢,2005(4):26.(WANG Xiao-hong,XIE Bing,FENG Zhong-yu.Present status and development of research on free cutting steel at home and abroad[J].Special Steel,2005(4):26.)
[2] 黄周华,阙宗华,董军.100 tDC EAF-LF-VD-CC流程硫易切削钢SAE1144的生产实践[J].特殊钢,2016(2):39.(HUANG Zhou-hua,QUE Zong-hua,DONG Jun.Production practice of sulphur free-cutting steel SAE1144 by 100 t DC EAF-LF-VD-CC flowsheet[J].Special Steel,2016(2):39.)
[3] 谢啸宇, 顾超, 王敏, 等. 中高硫钢中硫化锰夹杂物控制技术[J]. 钢铁, 2021, 56(12): 52.(XIE Xiao-yu, GU Chao, WANG Min,et al. Manganese sulfide inclusion control technology in medium and high sulfur steel[J]. Iron and Steel, 2021, 56(12): 52.)
[4] 邹虎, 王东兴, 陈永峰,等. 低碳含碲硫易切削钢的研究与实践[J]. 中国冶金, 2020, 30(12): 77. (ZOU Hu, WANG Dong-xing, CHEN Yong-feng, et al. Research and practice of low carbon free-cutting steel containing tellurium and sulfur[J]. China Metallurgy, 2020, 30(12): 77.)
[5] Bastien G P.The mechanism of formation of banded structures[J].Journal of Iron Steel Institute,1957(187):281.
[6] 林腾昌, 门兵, 程雄, 等. 热处理对铸态钢中硫化锰夹杂物的影响[J]. 中国冶金, 2021, 31(4): 48. (LIN Teng-chang, MEN Bing, CHENG Xiong, et al. Influence of heat treatment on MnS inclusion in as-cast steel[J]. China Metallurgy, 2021, 31(4): 48.)
[7] 沈昶, 陆强, 郭俊波,等. 中高碳铝镇静钢形成MnS塑性夹杂的工艺开发与实践[J]. 钢铁, 2021, 56(12): 62. (SHEN Chang, LU Qiang, GUO Jun-bo, et al. Development and practice on forming MnS plastic inclusion in medium high carbon Al killed steel[J]. Iron and Steel, 2021, 56(12): 62.)
[8] LI M, WANG F, LI C,et al. Effects of cooling rate and Al on MnS formation in medium-carbon non-quenched and tempered steels[J]. International Journal of Minerals, Metallurgy,and Materials,2015,22(6):589.
[9] Brody H D, Flemings M C.Solute redistribution in dendritic solidification[J].Tran Metall AIME,1966(236):615.
[10] Clyne T W, Kurz W. Solute redistribution during solidification with rapid solid state diffusion[J]. Metallurgical and Materials Transactions A,1981,12(6):965.
[11] Ohnaka I.Mathematical analysis of solute redistribution during solidification with diffusion in solid phase[J].Transactions of the Iron and Steel Institute of Japan,1986,26(12):1045.
[12] Kobayashi S. A Mathematical model for solute redistribution during dendritic solidification[J]. Transactions of the Iron and Steel Institute of Japan, 1988,28(7):535.
[13] Won Y M,Thomas B G.Simple model of micro-segregation during solidification of steels[J]. Metallurgical and Materials Transactions A,2001,32(7):1755.
[14] Goto H, Miyazawa K, Honma H. Effect of the primary oxide on the behavior of the oxide precipitating during solidification od steel[J].ISIJ International,1996,36(5):537.
[15] 蔡兆镇, 朱苗勇.钢凝固两相区溶质元素的微观偏析及其对连铸坯表面纵裂纹的影响[J].金属学报,2009,45(8):949.(CAI Zhao-zhen,ZHU Miao-yong,Microsegregation of solute elements in solidifying mushy zone of steel and its effect on longitudinal surface cracks of continuous casting strand[J].Acta Metallurgica Sinica,2009,45(8):949.)
[16] 蔡兆镇, 朱苗勇. 溶质偏析对连铸坯凝固前沿裂纹敏感性影响的研究[J].铸造技术,2009,30(11):1396.(CAI Zhao-zhen,ZHU Miao-yong. Influence of solute segregation on crack susceptibility at solidification front of continuous casting strand[J].Foundry Technology,2009,30(11):1396.)
[17] Matsumiya T, Kajioka H, Mizoguchi S,et al.Mathematical analysis of segregations in continuously-cast slabs[J].Transactions of the Iron and Steel Institute of Japan,1984,24(11):873.
[18] Ueshima Y, Mizoguchi S, Matsumiya T,et al. Analysis of solute distribution in dendrites of carbon steel with γ transformation during solidification[J]. Metallurgical Transactions B,1986,17(4):845.
[19] 雍岐龙.钢铁材料中的第二相[M].北京:冶金工业出版社,2006.(YONG Qi-long.The Second Phase in Steel Materials[M]. Beijing:Metallurgical Industry Press,2006.)
[20] Dutta B, Palmiere E, Sellars C. Modelling the kinetics of strain induced precipitation in Nb micro-alloyed steels[J]. Acta Matherialia, 2001,49(5):785.
[21] Zhang L, Pluschkell W. Nucleation and growth kinetics of inclusions during liquid steel deoxidation[J]. Ironmaking and Steelmaking, 2003,30(2):106.
[22] Wu W, Mao H, Jonsson P,et al.Effect of carbon content on the potency of the intragranular ferrite formation[J]. Steel Research International,2016,87(3):311.
[23] 孟利,汲家骏,何承绪,等. 取向硅钢中MnS粒子形核析出的动力学计算与分析[J]. 金属热处理,2015(3):11.(MENG Li,JI Jia-jun,HE Cheng-xu,et al.Kinetics calculation and analysis of MnS particles nucleation precipitation in grain-oriented silicon steel[J].Heat Treatment of Metals,2015(3):11.)
[24] WANG Y, YANG J, XIN X,et al. The effect of cooling conditions on the evolution of non-metallic inclusions in high manganese TWIP steels[J]. Metallurgical and Materials Transactions B,2016,47(2):1378.
[25] Takada H, Bessho I, Ito T. Effect of sulfur content and solidification variables on morphology and distribution of sulfide in steel ingots[J].Tetsu-to-Hagane,1976,62(10):1319.
[26] Kononov A A, Mogutnov B M. Effect of carbon on precipita-tion of MnS inhibitor in grain-oriented 3% silicon-steel[J].ISIJ International,1999,39(1):64.
[27] Hasegawa H, Nakajima K, Mizoguchi S. The growth of MnS precipitates in Fe-Si alloy[J].Tetsu-to-Hagane, 2002, 88(9): 493.
[28] Voorhees P W. The theory of Ostwald ripening[J].Journal of Statistical Physics, 1985,38(1/2):231.
[29] Greenwood G W. The growth of dispersed precipitates in solutions[J].Acta Metallurgica,1956,4(3):243.
[30] 吕迺冰,马跃,刘珂,等.车轴钢铸锭中MnS的生成、长大、熟化规律分析[J].钢铁,2020,55(7):58.(LÜ Nai-bing,MA Yue,LIU Ke,et al.Nucleation,growth and maturation analysis of MnS during solidification in axle steel ingots[J].Iron and Steel,2020,55(7):58.) |
| [1] |
MA Ming, ZHENG Xu-tao, YU Yao, WANG Shi, TIAN Zhen, XIE Qing-hua. Simulation of the effect of EMBr on the dynamic behavior of molten steel in thin slab with high casting speed[J]. CONTINUOUS CASTING, 2022, 41(5): 17-22. |
| [2] |
AN Shou-yong, WANG Peng-fei. Application of VUHZ detection and control system in ESP Line[J]. CONTINUOUS CASTING, 2022, 41(5): 125-131. |
| [3] |
ZHA Quan-chao, DENG Qi-gen, ZHANG Ya-bing, YANG Ren-qiang, LI Hai. PMO improves the central quality of φ300 mm round billet of low carbon steel[J]. CONTINUOUS CASTING, 2022, 41(4): 59-65. |
| [4] |
ZHAN Mei-zhu, WANG Sheng-dong, ZHANG Li-feng, CHEN Wei. Effect of casting speed on inclusions in continuous casting slab of peritectic tinplate steel[J]. CONTINUOUS CASTING, 2022, 41(3): 39-44. |
| [5] |
WANG Zhi-zheng, ZHONG Peng, WANG Huan. Optimization of tundish system for double-flow slab caster[J]. CONTINUOUS CASTING, 2022, 41(3): 65-70. |
| [6] |
LI Wei, TAN Zheng-jun, CHENG Jin-jun, LIN Qian, ZHANG Li-qiang. Quality improvement and practice of high speed continuous casting of billet based on secondary cooling optimization[J]. CONTINUOUS CASTING, 2022, 41(2): 95-99. |
|
|
|
|
2022, Vol. 57 
