Application Status and Development Trend of Continuous Casting Reduction Technology: A Review
Abstract
:1. Overview of Reduction Technology
1.1. The Continuous Casting Technology
1.2. The Formation Mechanism of Billet Segregation
1.3. Basic Principle of Reduction Technology
- (1)
- It compensates the solidification shrinkage at the center of billet, reducing or eliminating the internal shrinkage cavity and porosity formed by the volume shrinkage at the solidification end.
- (2)
- Under the extrusion effect of applied reduction amount, the molten steel enriched with solute elements is forced to flow in the opposite of the casting direction, which controls the transverse flow of molten steel, and reduces the center segregation.
- (3)
- The applied reduction amount can significantly break the “crystal bridge” and homogenizes the residual melt between the dendrites and controls the carbon macro-segregation, which further promotes the reverse flow of melt, and homogenizes the composition of constituents elements at the solidification end. The homogenization of melt further promotes the dendrites nucleation, refines the grains, increases the number of equiaxed dendrites, and improves the internal quality of billet and slab.
1.4. Development History of Reduction Technology
1.5. Classification of Reduction Technology
- (1)
- The reduction interval is different, as the SR is implemented at solid fraction range of 0.3–0.8, while the HR is implemented at the solidification end.
- (2)
- SR can only be achieved by adjusting the roll gap, while HR has to be concerned with pressure control besides the roll gap.
- (3)
- SR has a major role to overcome internal defects formation in ordinary steel grades, medium and low carbon steels, while the HR has outstanding results for high-quality steels, medium and high carbon steels. The similarities and differences between HR and SR technology are shown in Table 5.
2. Research on Reduction Technology
2.1. Experimental Research
2.2. Numerical Simulation Research
2.3. Industrial Field Research
2.4. Technical Parameters of Reduction Technology
2.4.1. Investigation of Process Parameters
- (1)
- Reduction interval
- (2)
- Reduction ratio
- (3)
- Total reduction amount
2.4.2. Research on Reduction Equipment
2.4.3. Factors Affecting the Reduction Technology
- (1)
- They developed an online detecting model for the solidification end of the continuous casting billet to investigate the feasible reduction position, which included heat-tracing model, thermal imaging of the billet surface, and nails shooting to calibrate the solid fraction of billet. Through verification with the actual production, the error of shell thickness was detected as 1.5%.
- (2)
- To achieve the optimized reduction amount, the formula of the minimum theoretical reduction at different positions was evaluated by using the concept that the reduction amount at the solidification end should be higher than the solidification shrinkage of billet.
- (3)
- The reduction interval was evaluated according to the principle that the solidifying metal should have a minimum degree of solute segregation after the implementation of reduction amount, which is considered as the best reduction interval. Furthermore, the segregation of different solute elements after the implementation of reduction technology was studied, and the formula for improving the degree of element segregation was obtained.
3. Industrial Implementation of Reduction Technology
4. Prospects of Reduction Technology
5. Future Perspective
- (1)
- How to measure the temperature distribution of the billet during solidification and how to calculate the volume shrinkage at the solidification end to provide a basis for the theoretical calculation of the reduction parameters. New research methods and ideas should be adopted for the reduction technology, such as the effect of alloy composition on the mechanical properties of cast products, the relationship between cooling water intensity and billet solidification, etc., and a breakthrough in the quantification of reduction parameters.
- (2)
- The research on the secondary cooling process is not enough to implement it in the practical application of the reduction technology, especially the relationship between the water intensity in the secondary cooling zone and solidification.
- (3)
- It is difficult to accurately judge the position of the solidification end of the cast products, especially when the casting speed and cooling water intensity changed. The selection of an appropriate reduction interval and amount also needs to be further investigated. The exact control of solidification end point is needed to improve the internal quality of cast products. Further research should be conducted on the transition states of different steel grades and the fluidity of molten steel in the two-phase zone, along with the optimization in the design of reduction rollers.
- (4)
- How to use the reduction technology for industrial production, as the investigations on reduction technology are mainly discontinuous, and a complete research system of reduction technology has not been designed. According to the actual working conditions and the current investigations, a systematic research system of reduction technology should be designed to automatically adjust the reduction parameters such as reduction interval, reduction amount, and reduction equipment.
- (5)
- With the progress of HR technology, the mechanical equipment also needs to be upgraded to improve the fault-tolerance of HR technology during its use in the industry. Safety measures should be highly considered according to the results of destructive experiments in order to avoid serious tragedy during the industrial production process.
Author Contributions
Funding
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
- Zhang, L.W.; Wang, Z.L.; Xu, C.J.; Li, S.L.; Ai, X.G.; Li, J. A vertical continuous casting machine for large blooms. Ironmak. Steelmak. 2017, 46, 742–746. [Google Scholar] [CrossRef]
- Lu, Y.J.; Wang, Q.; Li, Y.G.; He, S.P.; He, Y.M.; Pan, S.S.; Zhang, J.G.; Hu, B. Prevention of transverse corner cracks in continuously cast steel slabs using asymmetric secondary cooling nozzle. Ironmak. Steelmak. 2011, 38, 561–565. [Google Scholar] [CrossRef]
- Liu, Z.; Li, B. Effect of vertical length on asymmetric flow and inclusion transport in vertical-bending continuous caster. Powder Technol. 2018, 323, 403–415. [Google Scholar] [CrossRef]
- Samarasekera, I.; Brimacombe, J. The continuous–Casting mould. Int. Mater. Rev. 1978, 23, 286–300. [Google Scholar] [CrossRef]
- Ono, S. On the Operations of Circular Arc Type Bloom Continuous Casting and Product Qualities. Tetsu-to-Hagane 1974, 60, 953–961. [Google Scholar] [CrossRef] [Green Version]
- Nozaki, T.; Itoyama, S. Horizontal Continuous Casting Processes The State of the Art and Future Trends. Trans. Iron Steel Inst. Jpn. 1987, 27, 321–331. [Google Scholar] [CrossRef] [Green Version]
- Li, J.; Sun, Y.H.; An, H.H.; Ni, P.Y. Shape of slab solidification end under non-uniform cooling and its influence on the central segregation with mechanical soft reduction. Int. J. Miner. Metall. Mater. 2021, 28, 1788–1798. [Google Scholar] [CrossRef]
- Aboutalebi, M.; Reza, M.; Guthrie, R. Coupled turbulent flow, heat, and solute transport in continuous casting processes. Metall. Mater. Trans. B 1995, 26, 731–744. [Google Scholar] [CrossRef]
- Janssen, R.; Bart, G.; Cornelissen, M. Macrosegregation in continuously cast steel billets and blooms. App. Sci. Res. 1994, 52, 21–35. [Google Scholar] [CrossRef]
- Suzuki, A. Cast Structure of Continuously Cast Steel Ingot. Tetsu-to-Hagané 1974, 60, 774–783. [Google Scholar] [CrossRef]
- Murao, T.; Kajitani, T.; Yamamura, H. Simulation of the Center-line Segregation Generated by the Formation of Bridging. ISIJ Int. 2014, 54, 359–365. [Google Scholar] [CrossRef] [Green Version]
- Flemings, M. Our understanding of macrosegregation, Past and present. ISIJ Int. 2000, 40, 833–841. [Google Scholar] [CrossRef]
- Ludwig, A.; Wu, M.; Kharicha, A. On macrosegregation. Metall. Mater. Trans. A 2015, 46, 4854–4867. [Google Scholar] [CrossRef]
- Kajatani, T.; Drezet, J.; Rappaz, M. Numerical simulation of deformation-induced segregation in continuous casting of steel. Metall. Mater. Trans. A 2001, 32, 1479–1491. [Google Scholar] [CrossRef] [Green Version]
- Jiang, D.; Wang, W.; Luo, S.; Ji, C.; Zhu, M. Numerical simulation of slab centerline segregation with mechanical reduction during continuous casting process. Int. J. Heat Mass Transf. 2018, 122, 315–323. [Google Scholar] [CrossRef]
- Chen, X.; Deng, W.; Niu, S. Industrial Application of Mechanical Reduction on Continuous Casting of Bearing Steel Bloom. Processes 2021, 9, 2280. [Google Scholar] [CrossRef]
- Ayata, K.; Mori, H.; Taniguchi, K.; Matsuda, H. Low superheat teeming with electromagnetic stirring. ISIJ Int. 1995, 35, 680–685. [Google Scholar] [CrossRef]
- Oh, K.; Chang, Y. Macrosegregation behavior in continuously cast high carbon steel blooms and billets at the final stage of solidification in combination stirring. ISIJ Int. 1995, 35, 866–875. [Google Scholar] [CrossRef] [Green Version]
- Thome, R.; Harste, K. Principles of billet soft-reduction and consequences for continuous casting. ISIJ Int. 2006, 46, 1839–1844. [Google Scholar] [CrossRef] [Green Version]
- Hattori, M. Development of Technology for Elimination of Segregation in Continuously Cast Slabs. In Steelmaking Conference Proceedings; Iron & Steel Society: Warrendale, PA, USA, 1989; Volume 72, pp. 91–96. [Google Scholar]
- Masaoka, T. Improvement of Centerline Segregation in Continuously Cast Slab with Soft Reduction Technique. In Steelmaking Conference Proceedings; Iron & Steel Society: Warrendale, PA, USA, 1989; Volume 72, pp. 63–69. [Google Scholar]
- Zong, N.; Huang, J.; Liu, Y.; Lu, Z. Controlling centre segregation and shrinkage cavities without internal crack in as-cast bloom of steel GCr15 induced by soft reduction technologies. Ironmak. Steelmak. 2021, 48, 944–952. [Google Scholar] [CrossRef]
- Wang, Y.; Zhang, L.; Yang, W.; Ji, S.; Ren, Y. Effect of mold electromagnetic stirring and final electromagnetic stirring on the solidification structure and macrosegregation in bloom continuous casting. Steel Res. Int. 2021, 92, 2000661. [Google Scholar] [CrossRef]
- Ludlow, V.; Normanton, A.; Anderson, A.; Thiele, M.; Ciriza, J.; Laraudogoitia, J.; van der Knoop, W. Strategy to minimise central segregation in high carbon steel grades during billet casting. Ironmak. Steelmak. 2005, 32, 68–74. [Google Scholar] [CrossRef]
- Zhong, H.; Wang, R.; Han, Q.; Fang, M.; Yuan, H.; Song, L.; Xie, X.; Zhai, Q. Solidification structure and central segregation of 6Cr13Mo stainless steel under simulated continuous casting conditions. J. Mater. Res. Technol. 2022, 20, 3408–3419. [Google Scholar] [CrossRef]
- Li, G.; Zhang, K.; Han, C.; Chen, Y.; Zhao, G.; Cai, K. SMART/ASTC dynamic soft reduction technology and its application on the bloom continuous caster at Pangang. Int. J. Miner. Metall. Mater. 2006, 13, 121–124. [Google Scholar] [CrossRef]
- Wang, W.; Ning, L.; Bülte, R.; Bleck, W. Formation of internal cracks in steel billets during soft reduction. Int. J. Miner. Metall. Mater. 2008, 15, 114–119. [Google Scholar] [CrossRef]
- Han, Y.; Yan, W.; Zhang, J.; Chen, W.; Chen, J.; Liu, Q. Optimization of Thermal Soft Reduction on Continuous-Casting Billet. ISIJ Int. 2020, 60, 106–113. [Google Scholar] [CrossRef] [Green Version]
- Yao, Y.; Wang, B.; Liu, S.; Zhong, L.; Shen, S.; Chen, Z.; Zhang, J. Thermomechanical Analysis of the Effects of Water Distribution on Cracks during Vertical Continuous Casting under Soft Reduction Conditions. Adv. Mater. Sci. Eng. 2020, 2020, 5353690. [Google Scholar] [CrossRef] [Green Version]
- Li, L.; Zhang, Z.; Luo, M.; Li, B.; Lan, P.; Zhang, J. Control of shrinkage porosity and spot segregation in Ø195 mm continuously cast round bloom of oil pipe steel by soft reduction. Metals 2020, 11, 9. [Google Scholar] [CrossRef]
- Chen, X.; Nian, Y.; Xiong, L.; Naqash, A.; Zhang, L. Effect of soft reduction on internal pore and cracks of medium carbon steel. Mod. Transp. Metall. Mater. 2022, 2, 51–56. [Google Scholar]
- Chen, Y.; Li, G.J.; Yang, S.B.; Zhu, M.Y. Dynamic Soft Reduction for Continuously Cast Rail Bloom. J. Iron Steel Res. Int. 2007, 14, 13–17. [Google Scholar] [CrossRef]
- Chu, R.S.; Li, Z.J.; Liu, J.G.; Fan, Y.; Liu, Y.; Ma, C.W. Effect of soft reduction process on segregation of a 400 mm thick high-alloy steel slab. J. Iron Steel Res. Int. 2021, 28, 272–278. [Google Scholar] [CrossRef]
- Domitner, J.; Wu, M.; Kharicha, A. Modeling the effects of strand surface bulging and mechanical soft reduction on the macrosegregation formation in steel continuous casting. Metall. Mater. Trans. A 2014, 45, 1415–1434. [Google Scholar] [CrossRef]
- Zhao, J.P.; Liu, L.; Wang, W.W.; Zhou, W.J.; Lu, H. Effects of heavy reduction technology on internal quality of continuous casting bloom. Ironmak. Steelmak. 2019, 46, 227–234. [Google Scholar] [CrossRef]
- Rogberg, B.; Ek, L. Influence of Soft Reduction on the Fluid Flow, Porosity and Center Segregation in CC High Carbon and Stainless Steel Blooms. ISIJ Int. 2018, 58, 478–487. [Google Scholar] [CrossRef] [Green Version]
- Miyazawa, K.I. Continuous casting of steels in Japan. Sci. Technol. Adv. Mater. 2001, 2, 59–65. [Google Scholar] [CrossRef]
- Sivesson, P.; Raihle, C.; Konttinen, J. Thermal soft reduction in continuously cast slabs. Mater. Sci. Eng. A 1993, 173, 299–304. [Google Scholar] [CrossRef]
- Yim, C.; Park, J.; You, B.; Yang, S. The effect of soft reduction on center segregation in CC slab. ISIJ Int. 1996, 36, S231–S234. [Google Scholar] [CrossRef] [PubMed]
- Ji, C.; Zhu, M. Development and application of dynamic soft reduction technology for continuous casting machine. Miner. Met. Mater. Soc. 2010, 2, 14–18. [Google Scholar]
- Wu, C.; Ji, C.; Zhu, M. Influence of differential roll rotation speed on evolution of internal porosity in continuous casting bloom during heavy reduction. J. Mater. Process. Technol. 2019, 271, 651–659. [Google Scholar] [CrossRef]
- Zeze, M.; Misumi, H.; Nagata, S.; Mizoguchi, S.; Shirai, T.; Tsuneoka, A. Improvement of semi-macro segregation in continuously cast slabs by controlled plane reduction. Tetsu-to-Hagané 2001, 87, 77–84. [Google Scholar] [CrossRef] [Green Version]
- Joo, S. The Initiatives of Steel Technology Development at POSCO. In Proceedings of the 6th International Congress on the Science and Technology of Steelmaking, Beijing, China, 12–14 May 2015; pp. 29–34. [Google Scholar]
- Kawamoto, M. Recent Development of Steelmaking Process in Sumitomo Metals. J. Iron Steel Res. Int. 2011, 18, 28–35. [Google Scholar]
- Li, J.; Xu, W.; Cheng, S. Effect of the soft reduction of secondary cooling zone on the flow field of molten steel in the mold and the secondary cooling zone. J. Phys. Conf. Ser. 2021, 2044, 012148. [Google Scholar] [CrossRef]
- Jiang, M.; Yang, E.J.; Hou, Z.W.; Wang, X.H. Decreasing Porosities in Continuous Casting Thick Slab by Soft Reduction Technology. Metall. Mater. Trans. B 2021, 52, 2753–2759. [Google Scholar] [CrossRef]
- Emi, T. Steelmaking technology for the last 100 years: Toward highly efficient mass production systems for high quality steels. ISIJ Int. 2015, 55, 36–66. [Google Scholar] [CrossRef] [Green Version]
- Naito, M. Development of ironmaking technology. Shinnittetsu Giho 2006, 384, 2. [Google Scholar]
- Normanton, A.; Barber, B.; Butler, J. 26th International ATS Steelmaking Conference. Ironmak Steelmak. 2006, 33, 257–276. [Google Scholar] [CrossRef]
- Lee, Y. Rod and Bar Rolling: Theory and Applications; CRC Press: Boca Raton, FL, USA, 2004. [Google Scholar]
- Chenggong, Y. Application and Development of Soft Reduction Technology in continuous casting. Met. Mater. Metall. Eng. 2011, 39, 52–56. [Google Scholar]
- Takubo, M.; Matsuoka, Y.; Miura, Y.; Higashi, H.; Kittaka, S. NSENGI’s New Developed Bloom Continuous Casting Technology for Improving Internal Quality of Special Bar Quality. In Proceedings of the METEC 2nd ESTAD, Dusseldorf, Germany, 16–20 June 2015. [Google Scholar]
- Hiraki, S.; Yamanaka, A.; Shirai, Y. Development of new continuous casting technology (PCCS) for very thick plate. Mater. Jpn. 2009, 48, 20–22. [Google Scholar] [CrossRef] [Green Version]
- Yim, C.; Kwon, O. Advanced continuous casting technologies for cost reduction and improvement. J. Iron Steel Res. Int. 2008, 15, 52–58. [Google Scholar]
- Yim, C.; Won, Y.; Park, J. Continuous Cast Slab and Method for Manufacturing the Same. U.S. Patent 245,760, 8, 21 August 2012. [Google Scholar]
- Qian, L.; Chen, L.; Li, Z.; Han, L.; Bai, L.; Wu, P. Project practice of heavy reduction technology of billet. Contin. Cast. 2016, 41, 48–55. [Google Scholar]
- Wang, Y.-C.; Wang, Q.-J.; Xu, L.-J.; Qiu, S.-T. Application Situation of Soft Reduction During Process of Slab Continuous Casting. J. Iron Steel Res. 2012, 24, 1–6. [Google Scholar]
- Zhou, Q.; Yin, Y.; Zhang, J. Numerical Simulation Research and Application of Convex Roll for Efficient Soft Reduction of Continuous Casting Slab. Metall. Mater. Trans. B 2022, 53, 4029–4047. [Google Scholar] [CrossRef]
- Ma, H.; Zhang, J.; Yin, Y.; Yan, Z.; Liu, H. Numerical simulation on the centre macrosegregation during Billet continuous casting with the soft reduction. Ironmak. Steelmak. 2022, 49, 887–897. [Google Scholar] [CrossRef]
- Cherkashina, T.; Mazur, I.; Aksenov, S. Soft reduction of a cast ingot on the incomplete crystallization stage. Mater. Sci. Forum 2013, 762, 261–265. [Google Scholar] [CrossRef]
- Ali, N.; Zhang, L.; Zhou, H.; Zhao, A.; Zhang, C.; Gao, Y. Elucidation of void defects by soft reduction in medium carbon steel via EBSD and X-ray computed tomography. Mater. Des. 2021, 209, 109978. [Google Scholar] [CrossRef]
- Yao, C.; Wang, M.; Cheng, M.; Xing, L.; Wang, Y.; Gao, Y.; Bao, Y. Effect of Dynamic Soft Reduction Range and Amount on Central Segregation in Bloom and the Resulting Microstructure in the Rod of GCr15-Bearing Steel. Steel Res. Inter. 2022, 93, 2200495. [Google Scholar] [CrossRef]
- Bleck, W.; Wang, W.; Bülte, R. Influence of soft reduction on internal quality of high carbon steel billets. Steel Res. Int. 2006, 77, 485–491. [Google Scholar] [CrossRef]
- Wang, B.; Zhang, J.M.; Yin, Y.B.; Dong, Q.P.; Xiao, C. Study on the reduction efficiency of soft reduction on continuous casting bloom. Metall. Res. Technol. 2016, 113, 406. [Google Scholar] [CrossRef]
- Zong, N.; Jing, T.; Liu, Y. Influence of internal cracking on carbide precipitation in continuous casting bloom induced by soft reduction technology and the resulting segregated band In hot-rolled wire rods. Arch. Metall. Mater. 2022, 67, 73–82. [Google Scholar]
- Ali, N.; Zhang, L.; Zhou, H.; Zhao, A.; Zhang, C.; Fu, K.; Cheng, J. Investigation on Internal crack defects in medium carbon steel by soft reduction. Mater. Res. 2021, 24. [Google Scholar] [CrossRef]
- Rao, J.; Zhang, M.; Chen, J.; Zhao, L.; Bao, Y. Process Plactice on Improvement of Internal Quality of 300 mm x 400 mm Cast Bloom of Steel 42CrMo by Soft Reduction. Spec. Steel 2022, 43, 39. [Google Scholar]
- Chen, H.; Long, M.; Chen, D.; Liu, T.; Duan, H. Numerical study on the characteristics of solute distribution and the formation of centerline segregation in continuous casting (CC) slab. Int. J. Heat Mass Transf. 2018, 126, 843–853. [Google Scholar] [CrossRef]
- Long, M.; Dong, Z.; Chen, D.; Liao, Q.; Ma, Y. Effect of uneven solidification on the quality of continuous casting slab. Int. J. Mater. Prod. Technol. 2013, 47, 216–236. [Google Scholar] [CrossRef]
- Liu, K.; Zhang, J. Numerical analysis of optimum soft reduction amount for continuous casting slab. Metal. Int. 2012, 17, 14. [Google Scholar]
- Guan, R.; Ji, C.; Wu, C.; Zhu, M. Numerical modelling of fluid flow and macrosegregation in a continuous casting slab with asymmetrical bulging and mechanical reduction. Int. J. Heat Mass Transf. 2019, 141, 503–516. [Google Scholar] [CrossRef]
- Han, Z.; Chen, D.; Feng, K.; Long, M. Development and application of dynamic soft-reduction control model to slab continuous casting process. ISIJ Int. 2010, 50, 1637–1643. [Google Scholar] [CrossRef] [Green Version]
- Flemings, M. Solidification processing. Metall. Mater. Trans. B 2007, 510, 638–646. [Google Scholar]
- Luo, S.; Zhu, M.; Ji, C. Theoretical model for determining optimum soft reduction zone of continuous casting steel. Ironmak. Steelmak. 2014, 41, 233–240. [Google Scholar] [CrossRef]
- Wu, M.; Domitner, J.; Ludwig, A. Using a two-phase columnar solidification model to study the principle of mechanical soft reduction in slab casting. Metall. Mater. Trans. A 2012, 43, 945–964. [Google Scholar] [CrossRef]
- Liu, K.; Sun, Q.; Zhang, J.; Wang, C. A study on quantitative evaluation of soft reduction amount for CC bloom by thermo-mechanical FEM model. Metall. Res. Technol. 2016, 113, 504. [Google Scholar] [CrossRef] [Green Version]
- Kawawa, T.; Sato, H.; Miyahara, S.; Koyano, T.; Nemoto, H. Determination of solidifying shell thickness of continuously cast slab by rivet pin shooting. Tetsu-to-Hagané 1974, 60, 206–216. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Petrus, B.; Zheng, K.; Zhou, X. Real-time, model-based spray-cooling control system for steel continuous casting. Metall. Mater. Trans. B 2011, 42, 87–103. [Google Scholar] [CrossRef]
- Wang, Z.; Wang, X.; Liu, F.; Yao, M.; Zhang, X.; Yang, L.; Lu, H.; Wang, X. Vibration method to detect liquid-solid fraction and final solidifying end for continuous casting slab. Steel Res. Int. 2013, 84, 724–731. [Google Scholar] [CrossRef]
- Parker, R.; Manning, J.; Peterson, N.C. Application of pulse-echo ultrasonics to locate the solid/liquid interface during solidification and melting of steel and other metals. J. Appl. Phys. 1985, 58, 4150–4164. [Google Scholar] [CrossRef]
- Luo, S.; Zhu, M.Y.; Ji, C.; Chen, Y. Characteristics of solute segregation in continuous casting bloom with dynamic soft reduction and determination of soft reduction zone. Ironmak. Steelmak. 2010, 37, 140–146. [Google Scholar] [CrossRef]
- Yamada, M.; Ogibayashi, S.; Tezuka, M.; Mukai, T. Production of Hydrogen Induced Cracking (HIC) Resistant Steel by CC Soft Reduction. In 71st Steelmaking Conference Proceedings; Iron & Steel Society: Warrendale, PA, USA, 1988; pp. 71–85. [Google Scholar]
- Miaoyong, Z. Theoretical Analysis on Soft Reduction Gradient for Continuous Casting Slab. Angang Technol. 2007, 4, 1–5. [Google Scholar]
- Ji, C.; Luo, S.; Zhu, M. Analysis and application of soft reduction amount for bloom. ISIJ Int. 2014, 54, 504–510. [Google Scholar] [CrossRef] [Green Version]
- Sakaki, G.; Kwong, A.; Petozzi, J. Soft Reduction of Continuously Cast Blooms at Stelco’s Hilton Works. In 78th Steelmaking Conference Proceedings; Iron & Steel Society: Warrendale, PA, USA, 1995; Volume 78, pp. 295–300. [Google Scholar]
- Li, Y.; Li, L.; Zhang, J. Study and application of a simplified soft reduction amount model for improved internal quality of continuous casting bloom. Steel Res. Int. 2017, 88, 1700176. [Google Scholar] [CrossRef]
- Ali, N.; Zhang, L.; Zhou, H.; Zhao, A.; Zhang, C.; Fu, K.; Cheng, J. Effect of soft reduction technique on microstructure and toughness of medium carbon steel. Mater. Today Commun. 2021, 26, 102130. [Google Scholar] [CrossRef]
- An, H.; Bao, Y.P.; Wang, M.; Zhao, L.H. Reducing macro segregation of high carbon steel in continuous casting bloom by final electromagnetic stirring and mechanical soft reduction integrated process. Metall. Res. Technol. 2017, 114, 405. [Google Scholar] [CrossRef]
- Liu, K.; Wang, C.; Liu, G.L.; Ding, N.; Sun, Q.S.; Tian, Z.H. Research on Soft Reduction Amount Distribution to Eliminate Typical Inter-dendritic Crack in Continuous Casting Slab of X70 Pipeline Steel by Numerical Model. High Temp. Mater. Process. 2017, 36, 359–372. [Google Scholar] [CrossRef]
- Ali, N.; Zhang, L.; Sui, Z.; Zhou, H.; Zhang, C.; Nian, Y. Spatial Characterization of Internal Defects in Medium Carbon Steel via X-ray Computed Tomography. Steel Res. Int. 2022, 93, 2100777. [Google Scholar] [CrossRef]
- Liu, K.; Chang, Y.H.; Han, Z.G.; Zhang, J.Q. Effect of Asynchronous Adjustments of Clamping Cylinders on Triangular Crack of Slab Castings Under Application of Soft Reduction. J. Iron Steel Res. Int. 2013, 20, 38–47. [Google Scholar] [CrossRef]
- Cheng, R.; Zhang, J.; Zhang, L.; Ma, H. Comparison of porosity alleviation with the multi-roll and single-roll reduction modes during continuous casting. J. Mater. Process. Technol. 2019, 266, 96–104. [Google Scholar] [CrossRef]
- Zhang, J.; Chen, D.; Wang, S.; Long, M. Compensation control model of superheat and cooling water temperature for secondary cooling of continuous casting. Steel Res. Int. 2011, 82, 213–221. [Google Scholar] [CrossRef]
- Dong, Q.; Zhang, J.; Wang, B.; Zhao, X. Shrinkage porosity and its alleviation by heavy reduction in continuously cast strand. J. Mater. Process. Technol. 2016, 238, 81–88. [Google Scholar] [CrossRef]
- Tian, X.; Zhu, R.; Ji, C.; Zhu, M.; Li, Z. Application of Dynamic Soft Reducion Technology in Process of Concasting Bloom of Bearing Steel GCr15. Spec. Steel 2010, 31, 26–27. [Google Scholar]
- Yiqi, S.; Xihua, T.; Rongjun, X. Experimental study on heavy reduction of Baosteel NO.3 thick slab caster. Heavy Mach. 2019, 3, 16–21. [Google Scholar]
Type | Advantage | Shortcoming | Application | Challenge |
---|---|---|---|---|
Vertical type [1] | Inclusions can easily float and dissipate heat. | Large height, High investment cost, difficult maintenance. | Zhong Yuan Special Steel Company, et al. | How to reduce equipment height and investment cost. |
Vertical type with bending [2,3] | The height of the whole machine is less than others. | Transverse corner cracks can form. | Dillinger Steel Plant in Germany, et al. | How to eliminate the cracks in straightening process. |
Circular arc type with straight mould [4] | Float of inclusions, low investment cost. | Crack defects can easily produced. | NKK, Nippon Steel, et al. | How to eliminate the cracks in straightening process. |
Circular-arc type [5] | Low investment cost, beneficial to improve the quality. | Inclusions can easily segregate at the inner arc. | NSC Muroran Works, et al. | How to control the inclusion formation. |
Horizontal type [6] | Low investment cost, high surface quality. | Low production capacity. | Fukuyama works of nippon kokan, et al. | How to increase production capacity. |
Technical Methods | Advantage | Shortcoming |
---|---|---|
Electromagnetic stirring at solidification end [23] | Increases the number of equiaxed crystals in liquid cavities ensures the composition uniformity of liquid steel and decreases the macro-segregation. | The mixing position is difficult to control, and the maintenance cost is high; easy to cause negative segregation of white bright band; does not work when the solid fraction will large. |
Low superheat casting [24] | Increases the number of equiaxed crystals in liquid cavities, controls the formation of columnar crystals and center macro-segregation. | The nozzle is easy to be blocked at very low temperature; not conducive to inclusion floating; easy to cause semi-macro-segregation. |
Soft reduction [15,16] | Reduces the center segregation and controls the internal cracks formation. | High requirements for equipment and control parameters; high requirements for the end position of liquid core; poor dynamic adjustment applicability. |
Name | Time of Investigation | Technical Name | Application | Ref. |
---|---|---|---|---|
Static SR | Late 1970s | Segmented roll sector of small roll diameter | NKK Japan | [47] |
1980s | Enlarge roll gap contraction | Nippon Steel | [37] | |
1986 | Small pitch combined roll | Fukuyama Steel Works, Japan | [48] | |
Late 1980s | Artificial bulging soft reduction (ISBR) | NKK Japan | [49] | |
Early 1990s | Disc roll soft reduction (DRSR) | Nippon Steel | [50] | |
Dynamic SR | Late 1990s | Hydraulic clamping sector | VAI, SMS Demag, etc. | [38] |
HR | recent years | Crown roll large reduction amount | Nippon Steel, POSCO, etc. | [43] |
Reduction Technology | Force | Reduction Mode |
---|---|---|
SR technology | Thermal stress, Mechanical stress | Roller type Forged type Forced cooling at solidification end |
HR technology | - | Single point reduction Multipoint reduction |
- | Reduction Parameter | Section | Casting Speed | Steel Grade | Effect |
---|---|---|---|---|---|
SR | Small reduction amount, forward reduction interval, implemented at small solid fraction. | Small section billet | High casting speed | Medium and low carbon steel, alloyed steel | Improve the center segregation and center porosity. |
HR | Large reduction amount, backward reduction interval, implemented at high solid fraction. | Large section billet | Low casting speed | Medium and high carbon steel, alloyed steel | Improve center segregation and eliminates porosity. |
Enterprise | Type | Steel Grade | Reduction Amount/mm | Solid Fraction fs | Casting Speed m/min | Improvement Effect |
---|---|---|---|---|---|---|
Muroran Factory | SR | High carbon steel | 6~9 | 0.35~0.5 | - | Center segregation |
Sumitomo Metal | SR | Bearing steel | 6~9 | 0.4~0.8 | - | Center segregation |
Pohang, South Korea | SR | High carbon steel | 6~7 | 0.2~0.8 | - | Carbon segregation index decreases to 1.1 |
Xingtai Steel | SR | Bearing steel | 8.3~12.5 | 0.4~0.96 | 0.65~0.75 | Center and V-shape segregation |
Thyssen, Germany | SR | High carbon steel | - | 0.2~0.7 | 6.0~8.5 | Slab homogeneity |
MCC Continuous casting | HR | 72A | 5~20 | - | - | Eliminate porosity |
Pangang Group | HR | Bearing steel | - | 0.7~0.92 | - | Improve billet quality |
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
Nian, Y.; Zhang, L.; Zhang, C.; Ali, N.; Chu, J.; Li, J.; Liu, X. Application Status and Development Trend of Continuous Casting Reduction Technology: A Review. Processes 2022, 10, 2669. https://doi.org/10.3390/pr10122669
Nian Y, Zhang L, Zhang C, Ali N, Chu J, Li J, Liu X. Application Status and Development Trend of Continuous Casting Reduction Technology: A Review. Processes. 2022; 10(12):2669. https://doi.org/10.3390/pr10122669
Chicago/Turabian StyleNian, Yi, Liqiang Zhang, Chaojie Zhang, Naqash Ali, Jianhua Chu, Jiale Li, and Xiang Liu. 2022. "Application Status and Development Trend of Continuous Casting Reduction Technology: A Review" Processes 10, no. 12: 2669. https://doi.org/10.3390/pr10122669
APA StyleNian, Y., Zhang, L., Zhang, C., Ali, N., Chu, J., Li, J., & Liu, X. (2022). Application Status and Development Trend of Continuous Casting Reduction Technology: A Review. Processes, 10(12), 2669. https://doi.org/10.3390/pr10122669