360mm×450mm大方坯连铸动态轻压下压下模型的研究与应用
|
摘要
本文对大方坯连铸动态轻压下压下过程进行分析,建立了描述大方坯压下过程的压下模型并利用有限元计算软件MSC.MARC对其求解计算,研究了压下过程中铸坯内部应力/应变分布规律,并对该过程中的压下率进行分析。本文的主要研究内容和取得主要成果如下：
1.连铸大方坯自然热收缩的数值分析研究。热收缩值是动态轻压下在线控制模型中的一个重要参数。通过加载铸坯的实时温度场分布,对铸坯连铸过程进行热力耦合计算,获得了铸坯在整个过程的热收缩量。结果表明：拉速对铸坯的热收缩影响较大,随着拉速升高,铸坯上同一位置处的自然热收缩量越来越小,而过热度和钢种对铸坯的自然热收缩的影响则很小。
2.大方坯应力/应变的数值分析。对大方坯连铸过程进行数值模拟计算,获得铸坯内部及表面的应力/应变分布。研究表明：应力/应变在拉矫辊与铸坯接触处最大,并由铸坯表面向铸坯中心依次减小。
3.大方坯压下率数值分析研究。结合某厂板坯和方坯实际铸机条件,对铸坯轻压下过程进行三维有限元数值模拟计算,获得了不同压下量、钢种、拉速下压下率的变化规律。研究结果表明：方坯的压下率均沿拉坯方向近似线性减少；方坯的平均压下率与拉速呈线性减少关系；钢种对方坯压下率的影响小。
4.大方坯压下模型的在线应用研究。对拉矫辊的压下过程进行分析研究,根据连铸生产过程中拉速、凝固终点等条件的变化实现压下量的动态分配和动态压下；编制压下模型在线控制程序,将压下参数在大方坯连铸生产中动态实现。热试和投产半年内的大方坯质量表明轻压下的实施达到了预期的效果。
In this paper, soft reduction process of dynamic soft reduction was analyzed, by using finite element analysis software MSC.MARC, and the distribution of stress/strain inside the bloom as well as reduction gradient was investigated.The main research work and corresponding results as follows:
1. Numerical analysis of CC Bloom natural shrinking. The shrinking volume is an important parameter of bloom which was calculated during the whole CC process. The real-time temperature distribution of bloom was loaded, and the thermal coupling calculation was proceeded in the bloom continuous casting process. The shrinking volume of bloom was calculated during the whole CC process. The result shows that:As the casting speed increases, the shrinking volume becomes smaller, the casting speed has much greater effect on the bloom shrinking, and the effect of overheating on the natural shrinking of bloom becomes smaller.
2. Numerical analysis of the bloom stress/strain.By using the numerical simulation on bloom continuous casting process, we obtained the distribution of stress/strain inside the bloom. The result shows that:the stress/strain in straightening roller that contacting with the bloom is the largest, and reducing from the surface to the centre of bloom in turn.
3. Numerical analysis of the bloom reduction rate. With the actual conditions of slab bloom in a factory, a three-dimensional finite element numerical calculation was made in the process of bloom soft reduction, and the range and laws of reduction rate were obtained under various reduction volume, steel and casting speed. The research shows that:The reduction rate of bloom is approximately linearly reduction along the casting direction. The average reduction rate of bloom has a linear reduction relationship with the casting speed. The kind of steel has small influence on the reduction rate of bloom.
4. The online application research of Bloom soft reduction model. The research as well as analysis was done in the process of roll reduction. According to the change of casting speed, solidification end point and other parameters in the process of continuous casting production,the dynamic allocation and dynamic pressure of reduction volume were achieved. The reduction parameters were dynamic achieved at the manufacture of bloom continuous casting by establishing control procedures.After heat test and put into production for six months, the quality of the bloom shows that the implementation of soft reduction achieved the expected effect.
1.连铸大方坯自然热收缩的数值分析研究。热收缩值是动态轻压下在线控制模型中的一个重要参数。通过加载铸坯的实时温度场分布,对铸坯连铸过程进行热力耦合计算,获得了铸坯在整个过程的热收缩量。结果表明：拉速对铸坯的热收缩影响较大,随着拉速升高,铸坯上同一位置处的自然热收缩量越来越小,而过热度和钢种对铸坯的自然热收缩的影响则很小。
2.大方坯应力/应变的数值分析。对大方坯连铸过程进行数值模拟计算,获得铸坯内部及表面的应力/应变分布。研究表明：应力/应变在拉矫辊与铸坯接触处最大,并由铸坯表面向铸坯中心依次减小。
3.大方坯压下率数值分析研究。结合某厂板坯和方坯实际铸机条件,对铸坯轻压下过程进行三维有限元数值模拟计算,获得了不同压下量、钢种、拉速下压下率的变化规律。研究结果表明：方坯的压下率均沿拉坯方向近似线性减少；方坯的平均压下率与拉速呈线性减少关系；钢种对方坯压下率的影响小。
4.大方坯压下模型的在线应用研究。对拉矫辊的压下过程进行分析研究,根据连铸生产过程中拉速、凝固终点等条件的变化实现压下量的动态分配和动态压下；编制压下模型在线控制程序,将压下参数在大方坯连铸生产中动态实现。热试和投产半年内的大方坯质量表明轻压下的实施达到了预期的效果。
In this paper, soft reduction process of dynamic soft reduction was analyzed, by using finite element analysis software MSC.MARC, and the distribution of stress/strain inside the bloom as well as reduction gradient was investigated.The main research work and corresponding results as follows:
1. Numerical analysis of CC Bloom natural shrinking. The shrinking volume is an important parameter of bloom which was calculated during the whole CC process. The real-time temperature distribution of bloom was loaded, and the thermal coupling calculation was proceeded in the bloom continuous casting process. The shrinking volume of bloom was calculated during the whole CC process. The result shows that:As the casting speed increases, the shrinking volume becomes smaller, the casting speed has much greater effect on the bloom shrinking, and the effect of overheating on the natural shrinking of bloom becomes smaller.
2. Numerical analysis of the bloom stress/strain.By using the numerical simulation on bloom continuous casting process, we obtained the distribution of stress/strain inside the bloom. The result shows that:the stress/strain in straightening roller that contacting with the bloom is the largest, and reducing from the surface to the centre of bloom in turn.
3. Numerical analysis of the bloom reduction rate. With the actual conditions of slab bloom in a factory, a three-dimensional finite element numerical calculation was made in the process of bloom soft reduction, and the range and laws of reduction rate were obtained under various reduction volume, steel and casting speed. The research shows that:The reduction rate of bloom is approximately linearly reduction along the casting direction. The average reduction rate of bloom has a linear reduction relationship with the casting speed. The kind of steel has small influence on the reduction rate of bloom.
4. The online application research of Bloom soft reduction model. The research as well as analysis was done in the process of roll reduction. According to the change of casting speed, solidification end point and other parameters in the process of continuous casting production,the dynamic allocation and dynamic pressure of reduction volume were achieved. The reduction parameters were dynamic achieved at the manufacture of bloom continuous casting by establishing control procedures.After heat test and put into production for six months, the quality of the bloom shows that the implementation of soft reduction achieved the expected effect.
引文
1. Matsumiya T.连铸新技术[A],第三届发展中国家连铸会议论文集[C],2004：37-39.
2. 高爱民,卢玉英,王硕明.邯钢二炼钢厂板坯中心偏析的成因及对策[J],河北理工学院学报,2002,24(3)：23-28.
3. 蔡开科.浇注与凝固[M],北京：冶金工业出版社,1987,125-159.
4. 张彩军译.板坯中心偏析形成机理及轻压下技术的改善效果[A],中国钢铁年会论文集[C],2001,624-630.
5. 阎朝红.凝固末端轻压下技术在连铸中的应用[J],宝钢技术,2001,5：51-55.
6. Koichi E. Recent advances and future prospects of refining technology[J], Nippon Steel Technical Report,1994,61:1-8.
7. Lilja J, Lindstedt A. Improvement of steel cleanliness by slag composition control[J], Scandinavian Journal of Metallurgy,1996,25(2):65-72.
8. Jacobi H, Wunnenberg K. Improving oxide cleanness on basis of MIDAS method[J], Ironmaking and Steelmaking,2003,30(2):68-74.
9. Mirko J, Philipp G, Roman R, et al. Simulation of nonmetallic inclusions in a continuous casting strand[J], Steel Research International,2005,76(1):64-70.
10.麻永林,王宝峰,李保卫,等.扇形段电磁搅拌对U71Mn重轨钢质量的影响[J],钢铁,2001,37(9)：971-974.
11.胡坤太,仇圣桃,张慧,等.重钢小方坯连铸机内置式结晶器电磁搅拌器的研制[J],钢铁,2003,38(5)：22-24.
12. Kunstreich S, Dauby P H. Effect of liquid steel flow pattern on slab quality and the need for dynamic electromagnetic control in the mould[J], Ironmaking and Steelmaking,2005,32(1):80-86.
13.陈永,杨素波,朱苗勇.结晶器电磁搅拌改善重轨钢连铸坯内部质量的试验研究[J],钢铁,2007,42(2)：24-27.
14. Yamanaka A, Ota K, Terunuma M, et al. Reduction of center porosity of round billet by electromagnetic stirring in horizontal continuous casting[J], Tetsu-To-Hagane,1998, 84(9):609-616.
15. Spitzer K H, Georg R, Klaus S. Multi-frequency electromagnetic stirring of liquid metals [J], ISIJ International,1996,36(5):487-492.
16. Farrell M V, Ma N. Macrosegregation during alloyed semiconductor crystal growth in strong axial and transverse magnetic fields[J], International Journal of Heat and Mass Transfer,2004,47(14-16):3047-3055.
17.王晓东,李廷举,金俊泽.电磁场对连铸末端凝固过程的影响[J],金属学报,2001,37(9)：971-974.
18. Oh K S, Shin Y K, Chang Y W. Role of combination stirring and final stirring pool thickness on center defects of continuously cast high carbon steel blooms [J], Iron and Steelmaker,1994,21(4):43-55.
19. Sivesson P, Ortlund T, Widell B. Improvement of inner quality in continuously cast billets through thermal soft reduction and use of multivariate analysis of saved process variables [J], Ironmaking and Steelmaking,1996,23(6):504-511.
20. Birat J P. Innovation in steel continuous casting:past, present and future [J], Revue de Metallurgie,1999,96(11):1390-1399.
21.干勇.连续铸钢前沿技术的工程化[J],中国工程科学,2002,4(9)：12-17.
22.倪满森.我国连铸技术的进步及连铸技术发展动向[J],钢铁,2002,1：1-14,29.
23.王捷,杨拉道.连铸轻压下技术的最新发展[J],重型机械,2001,1：1-3.
24.钱静秋,智建国.连铸轻压下技术发展现状[J],钢铁,2002,10：S185-S188.
25.王朝盈,刘彩玲,刘光辉.厚板坯连铸轻压下技术和轻压下扇形段[J],重型机械,1999,5：9-11.
26. Jauhola M. The latest result of dynamic soft reduction in slab cc machine [A], Steelmaking conference Proceedings [C],2000,33(3):201-206.
27.孙蓟泉,周华勤.高效连铸及轻压下技术[J],机械工程与自动化,2004,2：4-8.
28. Okuda Y. Reduction of center cavity by forging with liquid core in round billet [J], Ironmaking and Steelmaking,1999,26(1):64-68.
29. Yamada M, Ogibayashi S, Tezuka M, et al. Production of hydrogen induced cracking (HIC) resistant steel by CC soft reduction [A],71st steelmaking conference processdings[C],1998:71-85.
30. Shigeaki O, Masayuki K, Mamoru Y, et al. Influence of soft reduction with one-piece rolls on center segregation in continuously cast slabs [J], ISIJ International,1991, 31(12):1400-1407.
31.林立恒译.利用轻压下法防止大方坯中心疏松技术的开发[J],冶金众译,1996,1：34-37，60.
32.陈超,阎朝红,康复.减少方坯中心偏析的冶金手段[J],宝钢技术,2001,4：53-57.
33.廖永松.轻压下技术在高碳钢方坯连铸中的应用[J],炼钢,2002,18(5)：35-39.
34. Yamanaka A, Okuda M. Reduction of centre cavity by forging with liquid core in round billet [J], Ironmaking and Steelmaking,1999,26(1):64-68.
35. Wolf M. Center segregation versus casting speed [J], CAMP ISIJ,1996,9:844.
36. Wolf M. Definition and control of strand soft reduction [J], CAMP ISIJ,1998,11:787.
37. Wang W J, Hu X G, Ning L X, et al. Improvement of center segregation in high-carbon steel billets using soft reduction [J], Journal of University of Science and Technology Beijing,2006,13(6):490-496.
38.陈其安,刘立文,王建伟,等.连铸坯带液芯轻压下时压塌现象的数值模拟研究[J],钢铁,2001,36(5)：44-46.
39. Zhu G S, Shi Z Y, Wang X H, et al. Two dimensional deformation characteristics of bloom CC with liquid core reduction [J], Journal of University of Science and Technology Beijing,2002,9(5):334-337.
40.马长文,沈厚发,黄天佑,等.板坯凝固末端轻压下流动与溶质分布的研究[J],铸造,2004,53(12)：1023-1027.
41.崔立新.板坯连铸动态轻压下工艺的三维热—力学模型研究[D),北京：北京科技大学,2006.
42.方文勇,吴迪平,秦勤.方坯连铸动态轻压下的研究[J],冶金设备,2005,12(6)：18-21.
43. Jimbo I, Cramb A W. The density of liquid iron carbon alloys [J], Metallurgical Transactions B,1993,24(1):5-10.
44. Won Y M, Kim K H, Yeo T J, et al. Effect of cooling rate on ZST, LIT, and ZDT of carbon steels near melting point [J], ISIJ International,1998,38(10):1093-1099.
45.张家泉,崔立新,陈志平,等.板坯连铸结晶器内温度/应力场耦合模型[J],北京科技大学学报,2004,26(4)：373-376.
46. Wray P J. Effect of carbon content on the plastic flow of plain carbon steels at elevated temperatures[J], Metallurgical Transactions A,1982,13(1):125-134.
47. Suzuki T. Creep properties of steel at continuous casting temperatures[J], Ironmaking and Steelmaking,1988,15(2):90-100.
48. Kozlowski P F, Thomas B G, Azzi J A, et al. Simple constitutive equations for steel at high temperature [J], Metallurgical Transactions A,1992,23:903-918.
49. Mizukami H, Murakami K, Miyashita Y. Mechanical properties of continuously cast steel at high temperatures [J], Tetsu-to-Hagane,1977,63(146):S652.
50. Friedman E. Thermomechannical analysis of the welding process using the finite element method [J], Transaction of the ASME, Journal of Pressure Vessel Technology, 1975,8:206-213.
51. Kelly J E, Michalek K P, Oconnor T G, et al. Initial development of thermal and stress fields in continuously cast steel billets [J], Metallurgical Transactions A,1988,19A: 2589-2602.
2. 高爱民,卢玉英,王硕明.邯钢二炼钢厂板坯中心偏析的成因及对策[J],河北理工学院学报,2002,24(3)：23-28.
3. 蔡开科.浇注与凝固[M],北京：冶金工业出版社,1987,125-159.
4. 张彩军译.板坯中心偏析形成机理及轻压下技术的改善效果[A],中国钢铁年会论文集[C],2001,624-630.
5. 阎朝红.凝固末端轻压下技术在连铸中的应用[J],宝钢技术,2001,5：51-55.
6. Koichi E. Recent advances and future prospects of refining technology[J], Nippon Steel Technical Report,1994,61:1-8.
7. Lilja J, Lindstedt A. Improvement of steel cleanliness by slag composition control[J], Scandinavian Journal of Metallurgy,1996,25(2):65-72.
8. Jacobi H, Wunnenberg K. Improving oxide cleanness on basis of MIDAS method[J], Ironmaking and Steelmaking,2003,30(2):68-74.
9. Mirko J, Philipp G, Roman R, et al. Simulation of nonmetallic inclusions in a continuous casting strand[J], Steel Research International,2005,76(1):64-70.
10.麻永林,王宝峰,李保卫,等.扇形段电磁搅拌对U71Mn重轨钢质量的影响[J],钢铁,2001,37(9)：971-974.
11.胡坤太,仇圣桃,张慧,等.重钢小方坯连铸机内置式结晶器电磁搅拌器的研制[J],钢铁,2003,38(5)：22-24.
12. Kunstreich S, Dauby P H. Effect of liquid steel flow pattern on slab quality and the need for dynamic electromagnetic control in the mould[J], Ironmaking and Steelmaking,2005,32(1):80-86.
13.陈永,杨素波,朱苗勇.结晶器电磁搅拌改善重轨钢连铸坯内部质量的试验研究[J],钢铁,2007,42(2)：24-27.
14. Yamanaka A, Ota K, Terunuma M, et al. Reduction of center porosity of round billet by electromagnetic stirring in horizontal continuous casting[J], Tetsu-To-Hagane,1998, 84(9):609-616.
15. Spitzer K H, Georg R, Klaus S. Multi-frequency electromagnetic stirring of liquid metals [J], ISIJ International,1996,36(5):487-492.
16. Farrell M V, Ma N. Macrosegregation during alloyed semiconductor crystal growth in strong axial and transverse magnetic fields[J], International Journal of Heat and Mass Transfer,2004,47(14-16):3047-3055.
17.王晓东,李廷举,金俊泽.电磁场对连铸末端凝固过程的影响[J],金属学报,2001,37(9)：971-974.
18. Oh K S, Shin Y K, Chang Y W. Role of combination stirring and final stirring pool thickness on center defects of continuously cast high carbon steel blooms [J], Iron and Steelmaker,1994,21(4):43-55.
19. Sivesson P, Ortlund T, Widell B. Improvement of inner quality in continuously cast billets through thermal soft reduction and use of multivariate analysis of saved process variables [J], Ironmaking and Steelmaking,1996,23(6):504-511.
20. Birat J P. Innovation in steel continuous casting:past, present and future [J], Revue de Metallurgie,1999,96(11):1390-1399.
21.干勇.连续铸钢前沿技术的工程化[J],中国工程科学,2002,4(9)：12-17.
22.倪满森.我国连铸技术的进步及连铸技术发展动向[J],钢铁,2002,1：1-14,29.
23.王捷,杨拉道.连铸轻压下技术的最新发展[J],重型机械,2001,1：1-3.
24.钱静秋,智建国.连铸轻压下技术发展现状[J],钢铁,2002,10：S185-S188.
25.王朝盈,刘彩玲,刘光辉.厚板坯连铸轻压下技术和轻压下扇形段[J],重型机械,1999,5：9-11.
26. Jauhola M. The latest result of dynamic soft reduction in slab cc machine [A], Steelmaking conference Proceedings [C],2000,33(3):201-206.
27.孙蓟泉,周华勤.高效连铸及轻压下技术[J],机械工程与自动化,2004,2：4-8.
28. Okuda Y. Reduction of center cavity by forging with liquid core in round billet [J], Ironmaking and Steelmaking,1999,26(1):64-68.
29. Yamada M, Ogibayashi S, Tezuka M, et al. Production of hydrogen induced cracking (HIC) resistant steel by CC soft reduction [A],71st steelmaking conference processdings[C],1998:71-85.
30. Shigeaki O, Masayuki K, Mamoru Y, et al. Influence of soft reduction with one-piece rolls on center segregation in continuously cast slabs [J], ISIJ International,1991, 31(12):1400-1407.
31.林立恒译.利用轻压下法防止大方坯中心疏松技术的开发[J],冶金众译,1996,1：34-37，60.
32.陈超,阎朝红,康复.减少方坯中心偏析的冶金手段[J],宝钢技术,2001,4：53-57.
33.廖永松.轻压下技术在高碳钢方坯连铸中的应用[J],炼钢,2002,18(5)：35-39.
34. Yamanaka A, Okuda M. Reduction of centre cavity by forging with liquid core in round billet [J], Ironmaking and Steelmaking,1999,26(1):64-68.
35. Wolf M. Center segregation versus casting speed [J], CAMP ISIJ,1996,9:844.
36. Wolf M. Definition and control of strand soft reduction [J], CAMP ISIJ,1998,11:787.
37. Wang W J, Hu X G, Ning L X, et al. Improvement of center segregation in high-carbon steel billets using soft reduction [J], Journal of University of Science and Technology Beijing,2006,13(6):490-496.
38.陈其安,刘立文,王建伟,等.连铸坯带液芯轻压下时压塌现象的数值模拟研究[J],钢铁,2001,36(5)：44-46.
39. Zhu G S, Shi Z Y, Wang X H, et al. Two dimensional deformation characteristics of bloom CC with liquid core reduction [J], Journal of University of Science and Technology Beijing,2002,9(5):334-337.
40.马长文,沈厚发,黄天佑,等.板坯凝固末端轻压下流动与溶质分布的研究[J],铸造,2004,53(12)：1023-1027.
41.崔立新.板坯连铸动态轻压下工艺的三维热—力学模型研究[D),北京：北京科技大学,2006.
42.方文勇,吴迪平,秦勤.方坯连铸动态轻压下的研究[J],冶金设备,2005,12(6)：18-21.
43. Jimbo I, Cramb A W. The density of liquid iron carbon alloys [J], Metallurgical Transactions B,1993,24(1):5-10.
44. Won Y M, Kim K H, Yeo T J, et al. Effect of cooling rate on ZST, LIT, and ZDT of carbon steels near melting point [J], ISIJ International,1998,38(10):1093-1099.
45.张家泉,崔立新,陈志平,等.板坯连铸结晶器内温度/应力场耦合模型[J],北京科技大学学报,2004,26(4)：373-376.
46. Wray P J. Effect of carbon content on the plastic flow of plain carbon steels at elevated temperatures[J], Metallurgical Transactions A,1982,13(1):125-134.
47. Suzuki T. Creep properties of steel at continuous casting temperatures[J], Ironmaking and Steelmaking,1988,15(2):90-100.
48. Kozlowski P F, Thomas B G, Azzi J A, et al. Simple constitutive equations for steel at high temperature [J], Metallurgical Transactions A,1992,23:903-918.
49. Mizukami H, Murakami K, Miyashita Y. Mechanical properties of continuously cast steel at high temperatures [J], Tetsu-to-Hagane,1977,63(146):S652.
50. Friedman E. Thermomechannical analysis of the welding process using the finite element method [J], Transaction of the ASME, Journal of Pressure Vessel Technology, 1975,8:206-213.
51. Kelly J E, Michalek K P, Oconnor T G, et al. Initial development of thermal and stress fields in continuously cast steel billets [J], Metallurgical Transactions A,1988,19A: 2589-2602.