20CrMnTiH齿轮钢在BOF-LF-RH-CC流程中的夹杂物演变

doi:10.13228/j.boyuan.issn1006-9356.20230485

Abstract
Figure/Table
References
Related Citation (15)

Download: PDF (0 KB) HTML (1 KB)
Export: BibTeX | EndNote (RIS)

Abstract 20CrMnTiH gear steel produced by a plant has a large amount of CaS inclusions during smelting, which affects the quality of casting billet. In order to study the evolution law of oxide inclusions in 20CrMnTiH gear steel and propose reasonable calcium treatment process, to reduce the precipitation of CaS in clusions, the 20CrMnTiH gear steel produced by BOF-LF-RH-CC process in a factory was sampled in the whole refining process. The evolution law and mechanism of oxide inclusions were studied through electron microscopy, inclusion automatic scanning analysis system and thermodynamic calculation. The results show that there is secondary oxidation of molten steel in the sulfur feeding line at the later stage of LF refining. The evolution law of oxide inclusions in refining process is as follows, pure Al₂O₃ inclusions→magnesia alumina spinel and some Al₂O₃-MgO-CaO composite inclusions→Al₂O₃-MgO-CaO and Al₂O₃-CaO composite inclusions after calcium treatment→a large number of Al₂O₃-MgO-CaO-CaS and Al₂O₃-CaO-CaS composite inclusions produced after feeding sulfur wire. According to the experiment and thermodynamic calculation, the calcium content in calcium treatment process is slightly lower than the precipitation condition of 12CaO·7Al₂O₃(C₁₂A₇) at the present stage. In order to modify the Al₂O₃ inclusion into 12CaO·7Al₂O₃ inclusion as much as possible, and achieve the ideal calcium treatment effect and save cost, the mass fraction of Ca required in the calcium treatment process should be controlled within 0.002 26%-0.003 00%. The composition of molten steel after sulfur feeding line can easily meet the precipitation conditions of CaS inclusions. During the production process, the time between calcium feeding line and sulfur feeding line should be extended, and feed the sulfur line after the calcium content decreasing, then move the sulfur feeding process in RH refining to reduce the precipitation of CaS inclusions. The research provides a theoretical basis for improving the cleanliness of sulfur-containing gear steel in industrial production processes.

Key words： 20CrMnTiH gear steel nonmetallic oxide inclusion the whole refining process calcium treatment evolution

Received: 25 August 2023

	Service

	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	YUAN Yibo
	YANG Libin
	ZHAO Jinxuan
	WANG Chengyi

Cite this article:

YUAN Yibo,YANG Libin,ZHAO Jinxuan等. Inclusions evolution in 20CrMnTiH gear steel during BOF-LF-VD-CC process[J]. China Metallurgy, 2024, 34(1): 36-43.

URL:

http://www.zgyj.ac.cn/EN/10.13228/j.boyuan.issn1006-9356.20230485 OR http://www.zgyj.ac.cn/EN/Y2024/V34/I1/36

[1]	张贵. 我国齿轮钢生产技术发展状况[J]. 工业加热,2015,44(5):46.(ZHANG G. The status of technical development of gear steel production in China[J]. Industrial Heating, 2015, 44(5): 46.)
[2]	张熹,崔京玉,章军. 浅析齿轮钢及热处理工艺对汽车用齿轮性能的影响[J]. 钢铁研究学报,2009,21(10):38.(ZHANG X,CUI J Y,ZHANG J. Brief discussion about gear steel products and effect of heat treatment on performance of automobile gear[J]. Journal of Iron and Steel Research, 2009, 21(10): 38.)
[3]	ZHANG Y L,YANG X G,XU J G,et al. Effects of alloying elements on the microstructure of 22CrMoH gear steels billets[J]. Advanced Materials Research,2011,1268:3.
[4]	DUGIC I,BERNDT R,JOSEFSSON S,et al. Non-metallic Inclusion and Their Effect on Fatigue Strength for Case-Hardened Carbon Steel in Gears[M]. Cham:Springer International Publishing,2018.
[5]	FERNANDES M,PIRES J C,CHEUNG N,et al. Investigation of the chemical composition of nonmetallic inclusions utilizing ternary phase diagrams[J]. Materials Characterization,2002,49(5):437.
[6]	安杰,王哲,李润霞,等. 汽车齿轮钢8620RH的洁净度[J]. 中国冶金,2016,26(9):33.(AN J,WANG Z,LI R X,et al. Cleanliness of automobile gear steel 8620RH[J]. China Metallurgy, 2016, 26(9): 33.)
[7]	王明林,赵沛,罗海文,等. 20CrMnTi齿轮钢热塑性的研究[J]. 钢铁,2001,36(4):50.(WANG M L,ZHAO P,LUO H W,et al. Hot ductility of 20CrMnTi pinion steel[J]. Iron and Steel, 2001, 36(4): 50.)
[8]	耿鑫, 宋波, 刘涛, 等. 38CrMoAl钢精炼过程夹杂物生成及演变规律[J].中国冶金, 2022, 32(11):106.(GENG X,SONG B,LIU T,et al. Inclusion generation and evolution of 38CrMoAl steel in refining process[J]. China Metallurgy, 2022, 32(11):106.)
[9]	葛允宗,颜慧成,王建军,等. 20CrMnTiH1齿轮钢中CaS夹杂的形成与控制[J]. 炼钢,2013,29(3):23.(GE Y Z,YAN H C,WANG J J,et al. Formation and control of CaS inclusion in gear steel 20CrMnTi1[J]. Steelmaking, 2013, 29(3): 23.)
[10]	LIU C Y, HUANG F X,SUO J L,et al. Effect of magnesia-carbon refractory on the kinetics of MgO·Al2O3 spinel inclusion generation in extra-low oxygen steels[J]. Metallurgical and Materials Transactions B,2016,47(2):989.
[11]	HIDEKAZU T,KENJI M. Effect of silica in slag on inclusion compositions in 304 stainless steel deoxidized with aluminum[J]. ISIJ International,2004,44(8):1350.
[12]	孙彦辉,方忠强. 钙处理中间产物的形成及其对氧化铝夹杂的改性[J]. 北京科技大学学报,2014,36(12):1615.(SUN Y H,FANG Z Q. Formation of intermediate products during calcium treatment and modification routes of alumina inclusions by intermediate products[J]. Journal of University of Science and Technology Beijing, 2014, 36(12): 1615.)
[13]	WANG X D,ZHANG D X,CHEN R L,et al. Application of calcium treatment to sulfur gear steel 20CrMo[J]. Advanced Materials Research,2014,3187:1323.
[14]	赵家七,蔡小锋,马建超,等. 铝镇静冷镦钢CaS结瘤机理及改进[J]. 钢铁,2021,56(9):80.(ZHAO J Q,CAI X F,MA J C,et al. Improvement on mechanism of nozzle clogging caused by CaS inclusions Al-killed heading steel[J]. Iron and Steel, 2021, 56(9): 8.)
[15]	王敏,包燕平,刘建华,等. 低碳铝镇静钢中(CaO)x·(Al2O3)y及CaS的形成与控制[J]. 钢铁,2009,44(12):46.(WANG M,BAO Y P,LIU J H, et al. Formation and control of (CaO)x·(Al2O3)y and CaS in low carbon Al-killed steel[J]. Iron and Steel, 2009, 44(12): 46.)
[16]	音正元,张立峰,李超,等. Q345D钢中含钙类夹杂物的演变和生成机理分析[J].钢铁,2020,55(11):47.(YIN Z Y,ZHANG L F,LI C,et al. Analysis of evolution and formation mechanism of calcium-containing inclusion of Q345D steel[J]. Iron and Steel, 2020, 55(11): 47.)
[17]	张立峰,李菲,方文.钢液钙处理过程中钙加入量精准计算的热力学研究[J]. 炼钢,2016,32(2):1.(ZHANG L F,LI F,FANG W. Thermodynamic investigation for the accurate calcium addition during calcium treatment of molten steels[J]. Steelmaking, 2016, 32(2): 1.)
[18]	杨光维,陈兆平,柳向椿. 非钙处理对高等级齿轮钢夹杂物的影响[J]. 钢铁,2020,55(4):40.(YANG G W,CHENG Z P,LIU X C. Effect of non-calcium treatment on inclusions in high grade case hardening steel[J]. Iron and Steel, 2020, 55(4):40.)
[19]	YANG G W,WANG X H,HUANG F X,et al. Influence of calcium addition on inclusions in LCAK steel with ultralow sulfur content[J]. Metallurgical and Materials Transactions,2015,46(1):145.
[20]	许国方,张雪良,杨树峰,等. 20CrMnTi齿轮钢冶炼全流程的夹杂物分析[J].中国冶金,2020,30(11):23.(XU G F,ZHANG X L,YANG S F,et al. Inclusion characterization in whole smelting process of 20CrMnTi gear steel[J]. China Metallurgy, 2020, 30(11): 23.)
[21]	杨光,杨文,张立峰. 铝镇静钢中夹杂物钙处理改性及其影响因素[J]. 钢铁, 2022, 57(12): 66.(YANG G,YANG W,ZHANG L F. Calcium treatment modification and influencing factors of inclusions in aluminum-killed steel[J]. Iron and Steel, 2022, 57(12): 66.)
[22]	吴松杰,杨文,张立峰等. 钙处理时机对LF-RH精炼过程Al2O3基夹杂物的影响[J].中国冶金, 2022, 32(1): 36.(WU S J,YANG W,ZHANG L F. Effect of calcium treatment time on Al2O3based inclusions during LF-RH refining process[J]. China Metallurgy, 2022, 32(1): 36.)
[23]	XU J F,HUANG F X,WANG X H. Formation mechanism of CaS-Al2O3 inclusions in low sulfur Al-killed steel after calcium treatment[J]. Metallurgical and Materials Transactions B, 2016, 47(2): 1217.
[24]	韩志军,林平,刘浏,等. 20CrMnTiH1齿轮钢钙处理热力学[J]. 钢铁,2007,42(9):32.(HAN Z P,LIN P,LIU L,et al. Thermodynamics of calcium treatment for 20CrMnTiH1[J]. Iron and Steel, 2007(9): 32.)
[25]	郭靖,程树森,程子建,等. 铝镇静钢钙处理后氧化铝夹杂物变性动力学模型[J]. 北京科技大学学报,2014,36(4):424.(GUO J,CHENG S S,CHENG Z J,et al. Kinetic modeling of alumina inclusion modification in Al-killed steel after Ca treatment[J]. Journal of University of Science and Technology Beijing, 2014, 36(4): 424.)
[26]	黄希祜. 钢铁冶金原理[M].北京:冶金工业出版社,2007.(HUANG X G. Principles of Iron and Steel Metallurgy[M]. Beijing: Metallurgical Industry Press, 2007.)
[27]	SUN G D,SUI Y F,WANG C G,et al. Thermodynamic calculation on calcium treatment for 26CrMo4S/2 steel[J]. Journal of Iron and Steel Research International,2014,21(S1):61.
[28]	YANG S F,WANG Q Q,ZHANG L F,et al. Formation and modification of MgO·Al2O3-based inclusions in alloy steels[J]. Metallurgical and Materials Transactions B,2012,43(4):731.
[29]	李超,李建新,姜静宇,等. 钢液成分对钙处理夹杂物改性效果的影响[J]. 中国冶金, 2020, 30(10):65.(LI C,LI J X,JIANG J Y,et al. Influence of molten steel composition on modification effect of inclusions during calcium treatment[J]. China Metallurgy, 2020, 30(10):65.)
[30]	刘坤龙,吕明,宋保民,等. Q355B铝镇静钢夹杂物演变及钙处理工艺优化[J]. 钢铁, 2022, 57(12): 79.(LIU K L,LÜ M,SONG B M,et al. Q355B aluminum calming steel inclusion evolution and calcium treatment process optimization[J]. Iron and Steel, 2022, 57(12): 79.)