轻压下对GCr15轴承钢大方坯内部质量的影响

doi:10.13228/j.boyuan.issn1006-9356.20200331

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Abstract Central soundness and carbide defects of bearing steel bars are closely related to the internal quality control of bloom castings. Taking GCr15 bearing steel as the research object, a two-dimensional longitudinal solidification and heat transfer model was established for the casting process of the bloom semi-products. The accuracy of solidification model is verified by field temperature measurement. Based on the theory of compensating the local solidification shrinkage and controlling the central shrinkage cavity under the soft reduction at the end of solidification, the reasonable soft reduction interval in the pasty region can be revealed through the accurate prediction of the solidification process. Among them, under the conditions of casting tests, the effective soft reduction interval corresponding to the solid phase ratio of the center of the casting is from 0.30 to 0.75, which refers to 16.4-22.5 m from the meniscus. The test results showed that the solidification structure and morphology of the bloom castings are little affected by soft reduction. However, after soft reduction, the central porosity index drops from greater than or equal to 1.5 to 0.5-1.5, which can meet the rolling requirements, and the central shrinkage cavity is basically disappeared, indicating that reasonable soft reduction position and moderate soft reduction amount can obviously improve the degree of central porosity and central shrinkage cavity of the bearing steel bloom castings, so as to improve the qualified rate of the following rolled material. However, the unreasonable or unstable distribution of the position and amount of press-down may lead to the occurrence of mid-way cracks, thus reducing the stability and consistency of the rolled material quality. For the present production, it is recommended to keep the constant casting speed and press down at No.3 to No.6 pressure roller to assure the internal quality of the steel.

Key words： bearing steel bloom casting solidification simulation soft reduction internal quality

Received: 02 June 2020

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	Articles by authors
	QI Meng
	LI Liang
	TIE Zhan-peng
	WANG Pu
	MIAO Hong-sheng
	ZHANG Jia-quan

Cite this article:

QI Meng,LI Liang,TIE Zhan-peng等. Influence of soft reduction on internal qualityof GCr15 bearing steel bloom castings[J]. China Metallurgy, 2020, 30(9): 67-74.

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http://www.zgyj.ac.cn/EN/10.13228/j.boyuan.issn1006-9356.20200331 OR http://www.zgyj.ac.cn/EN/Y2020/V30/I9/67

[1]	王国新. 大方坯连铸机动态轻压下系统开发与应用研究[D].北京:北京科技大学,2009.
[2]	Tamura A, Suzuki M, Kimura K, et al. Application of a soft reduction process with the bloom continuous caster in Kokura steel works[J]. Sumitomo Metals, 1993, 45: 103.
[3]	陈永. 重轨钢连铸的质量控制[J]. 钢铁,2004,39(3):23.
[4]	陈亮,宋波,陈天明,等.320 mm×410 mm大方坯连铸重轨钢质量改进与应用[J]. 钢铁,2017,52(4):31.
[5]	安航航,包燕平,王敏,等. 凝固末端电磁搅拌和轻压下复合技术对大方坯高碳钢偏析和中心缩孔的影响[J]. 北京科技大学学报, 2017, 39(7):996.
[6]	SUN Hai-bo, LI Lie-jun, YE De-xin, et al. On the alternate stirring mode of F-EMS for bloom continuous castings[J]. Metallurgical and Materials Transactions: B, 2018,49(4):1909.
[7]	JIANG D, ZHU M. Solidification structure and macrosegregation of billet continuous casting process with dual electromagnetic stirrings in mold and final stage of solidification: A numerical study[J]. Metallurgical and Materials Transactions:B, 2016, 47(6):3446.
[8]	Louhenkilpi S, Laitinen E, Nieminen R. Real-time simulation of heat transfer in continuous casting[J]. Metallurgical Transactions:B, 1993, 24(4):685.
[9]	王璞,李少翔,唐海燕,等. 大方坯径向水口旋流效应及其对凝固的影响[J]. 中国冶金,2019,29(9):15.
[10]	王璞,李少翔,陈列,等. 电磁搅拌对大圆坯结晶器冶金行为影响的探讨[J]. 钢铁,2019,54(8):82.
[11]	Lally B, Biegler L, Henein H. Finite difference heat-transfer modeling for continuous casting[J]. Metallurgical Transactions:B, 1990,21(4):761.
[12]	WANG H, LI G, LEI Y, et al. Mathematical heat transfer model research for the improvement of continuous casting slab temperature[J]. Transactions of the Iron and Steel Institute of Japan, 2006,45(9):1291.
[13]	陶文铨. 数值传热学[M]. 西安:西安交通大学出版社,2001.
[14]	LIU H, YANG C, ZHANG H, et al. Numerical simulation of fluid flow and thermal characteristics of thin slab in the funnel-type molds of two casters[J]. ISIJ International, 2011, 51(3): 392.
[15]	李少翔,张晓萌,李亮,等. 连铸流动与凝固耦合模拟中糊状区系数的表征及影响[J]. 工程科学学报,2019,41(2):199.
[16]	WANG Pu, ZHANG Zhuang, TIE Zhan-peng, et al. Initial transfer behavior and solidification structure evolution in a large continuously cast bloom with a combination of nozzle injection mode and M-EMS[J]. Metals,2019, 9(10):1083.
[17]	李少翔,王璞,兰鹏,等. 圆坯凝固末端电磁搅拌作用下的流动与传热行为[J]. 工程科学学报,2019,41(6):748.
[18]	王博,张炯明,肖超,等. 连铸板坯轻压下过程中间裂纹产生机理[J]. 工程科学学报,2016,38(3):351.
[19]	兰鹏,韩庚维,李亮,等. 直上钢Q235B板坯高拉速下中间裂纹的形成与调控[J]. 钢铁,2019,54(8):144.
[20]	HAN Z Q, CAI K K. Review of formation condition for internal crack in continuous casting slab[J]. Journal of lron and Steel Research,2001,13(1):68.