热成形模具混排式冷却系统冷却效果研究
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摘要
热冲压成形技术是一种将板料成形和冷却淬火相结合的新型复杂成形技术。运用该项技术将高强度钢板加工成车身结构件,既可以实现车身轻量化,又能保证汽车的安全性。热冲压成形件的强度主要取决于成形过程中奥氏体组织转化为马氏体组织的程度,而马氏体转化程度依赖于成形件的冷却速度及冷却均匀性,这势必要求热成形模具具备优良的冷却系统。混排式冷却系统采用型腔式水道、配合支撑柱进行扰流,可以有效的实现对成形件的快速均匀冷却。因此,深入研究热成形模具混排式冷却系统的冷却效果,对于加速混排式热成形模具在实际生产中的应用,推动汽车制造业的发展具有重要意义。
依据传热学和流体动力学相关原理,兼顾模具结构强度、数值模拟计算效率及计算精度,设计了混排式热成形模具,确定了数值模拟方法及湍流模型。
利用CFX流体分析软件建立热成形模具的有限元模型,对混排式热成形模具保压冷却阶段进行了数值模拟。分析了工艺条件对成形件和模具的热平衡状态及温度场分布的影响,得出了当冷却水流速为3.5m/s、保压时间为10s和保压力为12MPa时模具冷却效果最佳。
以BR1500HS热冲压硼钢板为试验材料,进行了盒形件混排式冷却系统的热冲压成形试验,分析了冷却水流速和保压时间对模具冷却效果的影响规律,验证仿真的可靠性和准确性,结合仿真分析确定了合理工艺参数,为混排式热成形模具的推广及其冷却系统的优化设计提供了科学依据和理论基础。
Hot stamping is a new complex forming technology, which realizes the combination of the process of forming and cooling quenching. High-strength steel can be processed into automobile body though hot stamping, which realizes the auto weight light and ensures the safety of automobile. The strength of formed parts depends mainly on the degree of it from austenite transformed into martensite in the forming process, and that the transformation degree of martensite relies on formed parts’cooling rate and cooling uniformity. Then hot stamping mould must be equipped with excellent cooling system. Mixed discharging type cooling system which uses cavity-type channels and cooperation of shores for spoiler can effectively achieve uniform and rapid cooling formed parts. Hence, it has important significance that further study the effect of mixed discharging cooling system to accelerating the use of hot stamping mould with mixed discharging type cooling system and promoting the development of automobile manufacturing industry.
The mixed discharging type hot stamping mould which gives a comprehensive consideration of the structure strength and rigidity of mould, the computational efficiency and accuracy, is simplified design follow the relevant theories and principles of heat transfer and fluid mechanics, and determined numerical simulation method and turbulence model.
The numerical simulation of the cooling effects of mixed discharging type hot stamping mould during packing stage was performed by CFX software, analyzed the influence of different technological conditions for temperature distribution and thermal equilibrium state of formed parts and dies, the cooling effect of the moulds turned to be the best with the holding pressure of 12MPa, the dwell time of 10s and the flow rate of water coolant of 3.5m/s.
Some experiments based on BR1500HS are completed in order to study the influence law of hot stamping mould cooling effect in water velocity and dwell time, verify the validity and feasibility of the numerical simulation, find the best process parameters, provide scientific basis and theoretical foundation for the extension of mixed type hot stamping mould and the optimization of its cooling system.
依据传热学和流体动力学相关原理,兼顾模具结构强度、数值模拟计算效率及计算精度,设计了混排式热成形模具,确定了数值模拟方法及湍流模型。
利用CFX流体分析软件建立热成形模具的有限元模型,对混排式热成形模具保压冷却阶段进行了数值模拟。分析了工艺条件对成形件和模具的热平衡状态及温度场分布的影响,得出了当冷却水流速为3.5m/s、保压时间为10s和保压力为12MPa时模具冷却效果最佳。
以BR1500HS热冲压硼钢板为试验材料,进行了盒形件混排式冷却系统的热冲压成形试验,分析了冷却水流速和保压时间对模具冷却效果的影响规律,验证仿真的可靠性和准确性,结合仿真分析确定了合理工艺参数,为混排式热成形模具的推广及其冷却系统的优化设计提供了科学依据和理论基础。
Hot stamping is a new complex forming technology, which realizes the combination of the process of forming and cooling quenching. High-strength steel can be processed into automobile body though hot stamping, which realizes the auto weight light and ensures the safety of automobile. The strength of formed parts depends mainly on the degree of it from austenite transformed into martensite in the forming process, and that the transformation degree of martensite relies on formed parts’cooling rate and cooling uniformity. Then hot stamping mould must be equipped with excellent cooling system. Mixed discharging type cooling system which uses cavity-type channels and cooperation of shores for spoiler can effectively achieve uniform and rapid cooling formed parts. Hence, it has important significance that further study the effect of mixed discharging cooling system to accelerating the use of hot stamping mould with mixed discharging type cooling system and promoting the development of automobile manufacturing industry.
The mixed discharging type hot stamping mould which gives a comprehensive consideration of the structure strength and rigidity of mould, the computational efficiency and accuracy, is simplified design follow the relevant theories and principles of heat transfer and fluid mechanics, and determined numerical simulation method and turbulence model.
The numerical simulation of the cooling effects of mixed discharging type hot stamping mould during packing stage was performed by CFX software, analyzed the influence of different technological conditions for temperature distribution and thermal equilibrium state of formed parts and dies, the cooling effect of the moulds turned to be the best with the holding pressure of 12MPa, the dwell time of 10s and the flow rate of water coolant of 3.5m/s.
Some experiments based on BR1500HS are completed in order to study the influence law of hot stamping mould cooling effect in water velocity and dwell time, verify the validity and feasibility of the numerical simulation, find the best process parameters, provide scientific basis and theoretical foundation for the extension of mixed type hot stamping mould and the optimization of its cooling system.
引文
[1]朱超.超高强度钢板的热冲压成形模具的设计及优化[D].长春:吉林大学学位论文,2010:1.
[2] Suehiro M, Kusumi K, Miyakoshi T. Properties of Aluminum Coated Steels for Hot Forming[J]. Journal of Materials Processing Technology, 2003(88):15-18.
[3] Yoshihara S, MacDonald B J, Nishimura H. Optimization of Magnesium Alloy Stamping with Local Heating and Cooling Using the Finite Element Method[J]. Journal of Materials Processing Technology, 2004(153–154):319-322.
[4] Naka T, Torikai G, Hino R. The Effects of Temperature and Forming Speed on the Forming Limit Diagram for Type5083 Aluminum-Magnesium Alloy Sheet[J]. Journal of Materials Processing Technology, 2001(113):648-653.
[5]周全.汽车超高强度硼钢板热成形工艺研究[D].上海:同济大学学位论文, 2007:2.
[6]谭志耀.超高强度钢板热冲压成形基础研究[D].上海:同济大学学位论文, 2006:4.
[7]李辉平,赵国君,张雷.超高强度钢板热冲压及模内淬火工艺的发展现状[J].山东大学学报,2010,40(3):70-71.
[8]谷诤巍,单忠德,徐虹.汽车高强度钢板冲压件热成形技术研究[J].模具工业,2009,35(4):28.
[9]王洪俊.轿车车身零件制造中的热成形技术[J].模具制造,2005,7(4):32.
[10]伍宏昆.热成形技术在汽车冲压领域的应用[J].汽车工艺与材料,2010,25(4):10.
[11]朱巧红,林建平,张健.汽车用U型件热成形模具散热的瞬态计算与分析[J].模具工程,2007,7(70/71):80.
[12]庄百亮,单忠德,姜超.热冲压成形工艺技术及其在车身上的应用[J].金属加工,2010,59(21):62-63.
[13]朱巧红.热成形模具热平衡分析及冷却系统设计优化[D].上海:同济大学学位论文,2007:2.
[14]孙国华.超高强度硼钢板高温成形极限研究[D].上海:同济大学学位论文,2009:2.
[15]徐劲力.汽车钢板弹簧热成型有限元模拟[J].热加工工艺,2008,37(19):77.
[16]徐伟力,艾健,罗爱辉.钢板热冲压新技术介绍[J].塑性工程学报,2009,16(4):42.
[17] Takahashi M, Development of High Strength Steels for Automobiles[J]. Nippon Steel Technical Report, 2003(88):3~7.
[18] Naderi M, Durrenberger L, Molinari A. Constitutive Relationships for 22MnB5 Boron Steel Deformed Isothermally at High Temperatures[J]. Materials Science and Engineering, 2008(A478):130~139.
[19] Mori K, Okuda Y. Tailor Die Quenching in Hot Stamping for Producing Ultra-high Strength Steel Formed Parts having Strength Distribution[J]. CIRP Annals-Manufacturing Technology, 2010 (59):291–294.
[20]马宁,胡平.高强度钢板热成形技术及其工程实现[J].汽车工艺与材料,2009,(12):12-13.
[21]孙阳.热冲压模具冷却系统仿真分析[D].哈尔滨:哈尔滨工业大学学位论文,2010:4.
[22] Merkleinl M, Lechler J. Investigation of the Thermo-mechanical Properties of Hot Stamping Steels[J]. Journal of Materials Processing Technology, 2006(177):452-455.
[23] Karbasian H, Tekkaya A E. A Review on Hot Stamping[J]. Journal of Materials Processing Technology, 2010(2010):2103-2118.
[24] Akerstrom P, Wikman B, Oldenbung M. Material Parameter Estimation for Boron Steel from Simultaneous Cooling and Compression Experiments[J]. Modeling and Simulation in Materials Science and Engineering, 2005(13):1291-1308.
[25] Akerstrom P, Oldenburg M. Austenite Decomposition During Press Hardening of a Boron Steel Computer Simulation and Test[J]. Journal of Materials Processing Technology, 2006(174):399-406.
[26] Akerstrom P, Oldenburg M. Numerical Simulation of a Thermo-mechanical Sheet Metal Forming Experiment[J]. Thermo-mechanical Sheet Metal Forming, 2006:1-15.
[27] Hoffmann H, So H, Steinbeiss H. Design of Hot Stamping Tools with Cooling System[J]. Annals of the CIRP, 2007(56):269-270.
[28] Naderi M, Ketabchi M, Abbsi M. Semi-hot Stamping as an Improved Process of Hot Stamping[J]. Journal of Materials Processing Technology, 2011(4):369-376.
[29] Turetta A, Bruschi A, Ghiotti A. Investigation of 22MnB5 Formability in Hot Stamping Operations[J]. Journal of Materials Processing Technology, 2006(177):396-400.
[30] Geiger M, Merklein M, Hoff C. Basic Investigation on the Hot Stamping Steel 22MnB5[J]. Journal of Advanced Materials Research, 2005:795-804.
[31]林建平,王立影.超高强度钢板热冲压成形研究与进展[J].热加工工艺,2008,37(21):141-142.
[32] Bariani P F, Bruschi S, Ghiotti A. Testing Formability in the Hot Stamping of HSS[J]. Journal of Materials Processing Technology, 2008(57):265-268.
[33] Gelin J C, Nguegang B V. Modeling of the Thermo-mechanical Coupling during Hot Forming of Viscoplastic Materials[J]. Journal of Materials Processing Technology, 1996(60):441-446.
[34] Ekkehard D. Hot Stamping a New Hot Forming Technology[J]. Thyssen Krupp Tech Forum, 2005(7):40-47.
[35]康斌.国内外高强度汽车板热冲压技术研究现状[J].冶金管理,2009(8):59-60.
[36]徐伟力,艾健.钢板热冲压新技术关键装备和核心技术[J].世界钢铁,2009(2):30-33.
[37]王立影,林建平,朱巧红.热冲压成形模具冷却系统临界水流速度研究[J].机械设计,2008,25(4):15-17.
[38]林建平,孙国华.超高强度钢板热成形板料温度的解析模型研究[J].锻压技术,2009,34(1):20-23.
[39] Xing Z W, Bao J, Yang Y Y. Numerical Simulation of Hot Stamping of Quenchable Boron Steel[J]. Journal of Material Engineering and Performance, 2009(499):28-31.
[40]李红林,贾志欣,邓益民.影响塑料注射制品变形的因素分析与研究[J].电加工与模具,2006(5):41-43.
[41] Liu H S, Xing Z W. Investigation of the Hot Stamping Process for Advanced High-Strength Steel Sheet by Numerical Simulation[J]. Journal of Material Engineering and Performance, 2010(19):325-334.
[42] Liu H S, Liu W, Xing Z W. Numerical and Experimental Investigation into Hot Forming of Ultra High Strength Steel Sheet[J]. Journal of Material Engineering and Performance , 2010(1):1-10.
[43] Bariani P F, Bruschi A, Ghiotti P. Critical Issues in the Simulation of Hot Forming Operations[J]. Eng. Res. Devel, 2010 (4):407-411.
[44]邢忠文,包军,杨玉英.可淬火硼钢热冲压成形试验研究[J].材料科学与工艺,2008,16(2):172-175.
[45] Bao J, Xing Z W, Yang Y Y. Hot Stamping Processing Experiments of Quenchable Boron Steel[J]. Materials Science Forum, 2008(575-578) :299~304.
[46]钟朝廷.高强度钢板热冲压成形研究[D].哈尔滨:哈尔滨工业大学学位论文,2006:22-47.
[47]包军.超高强度硼钢板热冲压成形及数值模拟研究[D].哈尔滨:哈尔滨工业大学学位论文,2008:40-90.
[48] Kim D H, Kim D M, Kang C G. Estimation of Die Service Life for a Die Cooling Method in a Forging Process[J]. International Journal of Advanced Manufacturer Technology, 2005(27):33-39.
[49] Kim Y J, Choi C H. A Study on Life Estimation of Hot Forging Die[J]. International Journal of Precision Engineering and Manufacturing, 2010(3):105-113.
[50]杨世铭.传热学基础[M].北京:高等教育出版社,2004:3.
[51]王福军.计算流体动力学[M].北京:清华大学出版社,2004:7.
[52]张志伟,刘建军.各种湍流模型在FLUENT中的应用[J].石家庄:河北水流,2008(10):25-26.
[2] Suehiro M, Kusumi K, Miyakoshi T. Properties of Aluminum Coated Steels for Hot Forming[J]. Journal of Materials Processing Technology, 2003(88):15-18.
[3] Yoshihara S, MacDonald B J, Nishimura H. Optimization of Magnesium Alloy Stamping with Local Heating and Cooling Using the Finite Element Method[J]. Journal of Materials Processing Technology, 2004(153–154):319-322.
[4] Naka T, Torikai G, Hino R. The Effects of Temperature and Forming Speed on the Forming Limit Diagram for Type5083 Aluminum-Magnesium Alloy Sheet[J]. Journal of Materials Processing Technology, 2001(113):648-653.
[5]周全.汽车超高强度硼钢板热成形工艺研究[D].上海:同济大学学位论文, 2007:2.
[6]谭志耀.超高强度钢板热冲压成形基础研究[D].上海:同济大学学位论文, 2006:4.
[7]李辉平,赵国君,张雷.超高强度钢板热冲压及模内淬火工艺的发展现状[J].山东大学学报,2010,40(3):70-71.
[8]谷诤巍,单忠德,徐虹.汽车高强度钢板冲压件热成形技术研究[J].模具工业,2009,35(4):28.
[9]王洪俊.轿车车身零件制造中的热成形技术[J].模具制造,2005,7(4):32.
[10]伍宏昆.热成形技术在汽车冲压领域的应用[J].汽车工艺与材料,2010,25(4):10.
[11]朱巧红,林建平,张健.汽车用U型件热成形模具散热的瞬态计算与分析[J].模具工程,2007,7(70/71):80.
[12]庄百亮,单忠德,姜超.热冲压成形工艺技术及其在车身上的应用[J].金属加工,2010,59(21):62-63.
[13]朱巧红.热成形模具热平衡分析及冷却系统设计优化[D].上海:同济大学学位论文,2007:2.
[14]孙国华.超高强度硼钢板高温成形极限研究[D].上海:同济大学学位论文,2009:2.
[15]徐劲力.汽车钢板弹簧热成型有限元模拟[J].热加工工艺,2008,37(19):77.
[16]徐伟力,艾健,罗爱辉.钢板热冲压新技术介绍[J].塑性工程学报,2009,16(4):42.
[17] Takahashi M, Development of High Strength Steels for Automobiles[J]. Nippon Steel Technical Report, 2003(88):3~7.
[18] Naderi M, Durrenberger L, Molinari A. Constitutive Relationships for 22MnB5 Boron Steel Deformed Isothermally at High Temperatures[J]. Materials Science and Engineering, 2008(A478):130~139.
[19] Mori K, Okuda Y. Tailor Die Quenching in Hot Stamping for Producing Ultra-high Strength Steel Formed Parts having Strength Distribution[J]. CIRP Annals-Manufacturing Technology, 2010 (59):291–294.
[20]马宁,胡平.高强度钢板热成形技术及其工程实现[J].汽车工艺与材料,2009,(12):12-13.
[21]孙阳.热冲压模具冷却系统仿真分析[D].哈尔滨:哈尔滨工业大学学位论文,2010:4.
[22] Merkleinl M, Lechler J. Investigation of the Thermo-mechanical Properties of Hot Stamping Steels[J]. Journal of Materials Processing Technology, 2006(177):452-455.
[23] Karbasian H, Tekkaya A E. A Review on Hot Stamping[J]. Journal of Materials Processing Technology, 2010(2010):2103-2118.
[24] Akerstrom P, Wikman B, Oldenbung M. Material Parameter Estimation for Boron Steel from Simultaneous Cooling and Compression Experiments[J]. Modeling and Simulation in Materials Science and Engineering, 2005(13):1291-1308.
[25] Akerstrom P, Oldenburg M. Austenite Decomposition During Press Hardening of a Boron Steel Computer Simulation and Test[J]. Journal of Materials Processing Technology, 2006(174):399-406.
[26] Akerstrom P, Oldenburg M. Numerical Simulation of a Thermo-mechanical Sheet Metal Forming Experiment[J]. Thermo-mechanical Sheet Metal Forming, 2006:1-15.
[27] Hoffmann H, So H, Steinbeiss H. Design of Hot Stamping Tools with Cooling System[J]. Annals of the CIRP, 2007(56):269-270.
[28] Naderi M, Ketabchi M, Abbsi M. Semi-hot Stamping as an Improved Process of Hot Stamping[J]. Journal of Materials Processing Technology, 2011(4):369-376.
[29] Turetta A, Bruschi A, Ghiotti A. Investigation of 22MnB5 Formability in Hot Stamping Operations[J]. Journal of Materials Processing Technology, 2006(177):396-400.
[30] Geiger M, Merklein M, Hoff C. Basic Investigation on the Hot Stamping Steel 22MnB5[J]. Journal of Advanced Materials Research, 2005:795-804.
[31]林建平,王立影.超高强度钢板热冲压成形研究与进展[J].热加工工艺,2008,37(21):141-142.
[32] Bariani P F, Bruschi S, Ghiotti A. Testing Formability in the Hot Stamping of HSS[J]. Journal of Materials Processing Technology, 2008(57):265-268.
[33] Gelin J C, Nguegang B V. Modeling of the Thermo-mechanical Coupling during Hot Forming of Viscoplastic Materials[J]. Journal of Materials Processing Technology, 1996(60):441-446.
[34] Ekkehard D. Hot Stamping a New Hot Forming Technology[J]. Thyssen Krupp Tech Forum, 2005(7):40-47.
[35]康斌.国内外高强度汽车板热冲压技术研究现状[J].冶金管理,2009(8):59-60.
[36]徐伟力,艾健.钢板热冲压新技术关键装备和核心技术[J].世界钢铁,2009(2):30-33.
[37]王立影,林建平,朱巧红.热冲压成形模具冷却系统临界水流速度研究[J].机械设计,2008,25(4):15-17.
[38]林建平,孙国华.超高强度钢板热成形板料温度的解析模型研究[J].锻压技术,2009,34(1):20-23.
[39] Xing Z W, Bao J, Yang Y Y. Numerical Simulation of Hot Stamping of Quenchable Boron Steel[J]. Journal of Material Engineering and Performance, 2009(499):28-31.
[40]李红林,贾志欣,邓益民.影响塑料注射制品变形的因素分析与研究[J].电加工与模具,2006(5):41-43.
[41] Liu H S, Xing Z W. Investigation of the Hot Stamping Process for Advanced High-Strength Steel Sheet by Numerical Simulation[J]. Journal of Material Engineering and Performance, 2010(19):325-334.
[42] Liu H S, Liu W, Xing Z W. Numerical and Experimental Investigation into Hot Forming of Ultra High Strength Steel Sheet[J]. Journal of Material Engineering and Performance , 2010(1):1-10.
[43] Bariani P F, Bruschi A, Ghiotti P. Critical Issues in the Simulation of Hot Forming Operations[J]. Eng. Res. Devel, 2010 (4):407-411.
[44]邢忠文,包军,杨玉英.可淬火硼钢热冲压成形试验研究[J].材料科学与工艺,2008,16(2):172-175.
[45] Bao J, Xing Z W, Yang Y Y. Hot Stamping Processing Experiments of Quenchable Boron Steel[J]. Materials Science Forum, 2008(575-578) :299~304.
[46]钟朝廷.高强度钢板热冲压成形研究[D].哈尔滨:哈尔滨工业大学学位论文,2006:22-47.
[47]包军.超高强度硼钢板热冲压成形及数值模拟研究[D].哈尔滨:哈尔滨工业大学学位论文,2008:40-90.
[48] Kim D H, Kim D M, Kang C G. Estimation of Die Service Life for a Die Cooling Method in a Forging Process[J]. International Journal of Advanced Manufacturer Technology, 2005(27):33-39.
[49] Kim Y J, Choi C H. A Study on Life Estimation of Hot Forging Die[J]. International Journal of Precision Engineering and Manufacturing, 2010(3):105-113.
[50]杨世铭.传热学基础[M].北京:高等教育出版社,2004:3.
[51]王福军.计算流体动力学[M].北京:清华大学出版社,2004:7.
[52]张志伟,刘建军.各种湍流模型在FLUENT中的应用[J].石家庄:河北水流,2008(10):25-26.