低压转子加热过程模拟及工艺优化
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摘要
随着计算机技术的迅速发展,热处理过程的计算机模拟越来越受到人们的重视,已经成为当前热处理过程研究和工艺设计中必不可少的重要部分。大锻件作为重要的装备零件,其质量和性能的要求越来越高。为满足需要,必须提高大锻件的热处理质量。由于大锻件的尺寸结构原因,传统以经验、定性方式制订热处理工艺过程已不能很好的满足需求。为节省人力物力财力,热处理的数值模拟作为一种新的工艺预测和制订方式出现在人们的眼前。对于大锻件,热处理过程的模拟对提高工件性能,降低变形和开裂倾向有着重要的意义。
本文在充分考虑加热过程中瞬态问题、相变潜热问题、热物性参数与温度的关系以及温度场、组织场相互作用的情况下,运用MSC.MARC有限元软件建立加热过程的有限元计算模型,并根据淬火温度组织要求,设定了工艺优化原则,并对原有工艺进行的模拟分析。通过改变加热工艺中的升温速度、中间保温温度和保温时间等工艺参数,对不同尺寸的30Cr2Ni4MoV低压转子进行工艺优化。
借助于计算机模拟,本文分析了阶梯加热过程中各工艺参数对加热过程中组织转变、均温情况和热应力大小的影响。结果表明:阶梯加热过程中的第一次升温速度能有效降低低压转子加热过程中产生的第一次最大温差和弹性状态下的最大热应力;中间保温温度的降低能降低第一次最大温差和最大热应力,但效果不甚明显;但其升高能有效降低第二次最大温差,减小表心部开始奥氏体化的时间间隔;第二次升温阶段的升温速度的增加会降低表面奥氏体化的时间,但对心部奥氏体化时间影响很小,同时会增加低压转子的均温时间。
根据模拟获得的各工艺参数对加热过程的影响,本文分别对φ1 768mm和φ2826mm低压转子进行了加热工艺优化。优化后的工艺,总加热时间上分别增加了20.5和60小时,能保证加热结束时转子表心部温差不超过10℃,基本达到均温转子全部奥氏体化,并有效降低了加热过程中产生的最大热应力值。
With the rapid development of computer technology, heat treatment computer simulation is receiving increasing attention, and has become an essential part in the process study and design of current heat treatment technology. As important equipment parts, the demand of large forgings’quality and performance are increasingly higher. To meet the needs, the heat treatment process of large forgings, a method to improve the forges performance, has to be improved. It is difficult to make out the proper heat treatment process by traditional empirical and qualitative method for the large forgings. So, in order to save resources, heat treatment simulation technology has appeared as a new solution way. For large forgings, heat treatment process is of great significance in improving the workpiece performance and reducing the deformation and cracking tendency.
Completely considering the temperature field, the microstructure field and the internal stress field of the heating process, a FEM model of heating process has been built based on the software package MSC.MARC. Based on the quenching requirement for the temperature and microstructure, the optimization principles are set, and the old heating processes have been simulated and analyzed. The heating processes of LP rotors with different diameter have been optimized by altering different process parameters, such as heating rate, the middle holding temperature, holding duration, and so on.
With the aid of computer simulation, the influence of different process parameters on the microstructure transformation, temperature uniformization and thermal-stress has been analyzed. The results show that: the heating rate of the first heating stage can effectively reduce the first largest temperature difference and the thermal-stress between the surface and center of the rotor; the reduction of the second holding step temperature can slightly reduce the first largest temperature difference and the thermal-stress,and its increasing can effectively decrease the second largest temperature difference and shorten the austenization beginning time gap between surface and center of LP roter; the austenization of the LP rotor is mainly related with the heating rate of the second heating stage, the higher the heating rate, the bigger time interval between austenization beginning time of the surface and center, and the more time needed to lessen the temperature difference between surface and center.
Based on the simulation results, the heating process of LP rotor with the diameter of 1768mm and 2826mm are respectively optimized. Although the total heating time increases 20.6 and 60 hours respectively in the optimized heating process, the temperature difference between surface and center of LP rotor can be under 10℃,the whole rotor can be homogeneously austenized, and the biggest thermal-stress can be reduced effectively.
本文在充分考虑加热过程中瞬态问题、相变潜热问题、热物性参数与温度的关系以及温度场、组织场相互作用的情况下,运用MSC.MARC有限元软件建立加热过程的有限元计算模型,并根据淬火温度组织要求,设定了工艺优化原则,并对原有工艺进行的模拟分析。通过改变加热工艺中的升温速度、中间保温温度和保温时间等工艺参数,对不同尺寸的30Cr2Ni4MoV低压转子进行工艺优化。
借助于计算机模拟,本文分析了阶梯加热过程中各工艺参数对加热过程中组织转变、均温情况和热应力大小的影响。结果表明:阶梯加热过程中的第一次升温速度能有效降低低压转子加热过程中产生的第一次最大温差和弹性状态下的最大热应力;中间保温温度的降低能降低第一次最大温差和最大热应力,但效果不甚明显;但其升高能有效降低第二次最大温差,减小表心部开始奥氏体化的时间间隔;第二次升温阶段的升温速度的增加会降低表面奥氏体化的时间,但对心部奥氏体化时间影响很小,同时会增加低压转子的均温时间。
根据模拟获得的各工艺参数对加热过程的影响,本文分别对φ1 768mm和φ2826mm低压转子进行了加热工艺优化。优化后的工艺,总加热时间上分别增加了20.5和60小时,能保证加热结束时转子表心部温差不超过10℃,基本达到均温转子全部奥氏体化,并有效降低了加热过程中产生的最大热应力值。
With the rapid development of computer technology, heat treatment computer simulation is receiving increasing attention, and has become an essential part in the process study and design of current heat treatment technology. As important equipment parts, the demand of large forgings’quality and performance are increasingly higher. To meet the needs, the heat treatment process of large forgings, a method to improve the forges performance, has to be improved. It is difficult to make out the proper heat treatment process by traditional empirical and qualitative method for the large forgings. So, in order to save resources, heat treatment simulation technology has appeared as a new solution way. For large forgings, heat treatment process is of great significance in improving the workpiece performance and reducing the deformation and cracking tendency.
Completely considering the temperature field, the microstructure field and the internal stress field of the heating process, a FEM model of heating process has been built based on the software package MSC.MARC. Based on the quenching requirement for the temperature and microstructure, the optimization principles are set, and the old heating processes have been simulated and analyzed. The heating processes of LP rotors with different diameter have been optimized by altering different process parameters, such as heating rate, the middle holding temperature, holding duration, and so on.
With the aid of computer simulation, the influence of different process parameters on the microstructure transformation, temperature uniformization and thermal-stress has been analyzed. The results show that: the heating rate of the first heating stage can effectively reduce the first largest temperature difference and the thermal-stress between the surface and center of the rotor; the reduction of the second holding step temperature can slightly reduce the first largest temperature difference and the thermal-stress,and its increasing can effectively decrease the second largest temperature difference and shorten the austenization beginning time gap between surface and center of LP roter; the austenization of the LP rotor is mainly related with the heating rate of the second heating stage, the higher the heating rate, the bigger time interval between austenization beginning time of the surface and center, and the more time needed to lessen the temperature difference between surface and center.
Based on the simulation results, the heating process of LP rotor with the diameter of 1768mm and 2826mm are respectively optimized. Although the total heating time increases 20.6 and 60 hours respectively in the optimized heating process, the temperature difference between surface and center of LP rotor can be under 10℃,the whole rotor can be homogeneously austenized, and the biggest thermal-stress can be reduced effectively.
引文
[1]东北重型机械学院.大锻件热处理[M].1974.
[2]康打韬,叶国斌.大型锻件材料及热处理.龙门书局出版,1998:166-168
[3]刘庄.热处理过程的数值模拟.北京:科学出版社,1996:1-2,304-310
[4]崔晓龙,万妮丽.大型锻件热处理过程的数值模拟研究.鞍钢技术,2004,6:41-44
[5]王大鹏.轴对称大锻件淬火过程温度场及组织场的数值模拟.[大连理工大学硕士学位论文].2002:2-6
[6]李强.淬火过程的计算机模拟与试验研究.[燕山大学工学博士学位论文].2003:15-16
[7]Pan Jiansheng.Research and application prospect of computer simulation on heat treatment process. Journal of Shanghai Jiao tong University,2000,E-5(1):1-13
[8]Π.B.斯科柳耶夫:大型锻件中的氢与白点,机械工业出版社,1966
[9]陈德和:钢的缺陷,机械工业出版社,1966.
[10]H.D.Emmert:Inverstigationof large steam turbin splindle failure,TASME,1956,Vol,78,p1547.
[11].B.Я.杜博沃依:钢中白点,冶金工业出版社,1955.
[12]高守义.热处理有限差分法模拟研究.大连理工大学学报,1989,29(2):183-190
[13]S.W.Han.Immersion Time Quenching.Advanced Material&Processes,1995(9):42AA-42DD
[14]Neil Zuckerm an, Impingement Heat Transfer: Correlations and Numerical Modeling, Journal lf Heat Transfer, May,2005.
[15]Ferrari, An Evaluation of Gas Quenching of Steel Rings by Multiple - jet Impingement,Mater Process Techno, 2003.
[16]H. W. Walton, Heat Treatment of Metals, 1983, 1.
[17]Y. Huo, Boundary /Finite Element Modeling of Three - Dimensional Electromagnetic Heating during Microwave Food Processing, Journal of Heat Transfer, October 2005.
[18]杨卓越等.新技术新工艺, 1996, 5.
[19]K. B londeau, Heat Treatment, 1976.
[20]M. G. Palafox, Proceeding of the second International con2. ference on quenching and the control of distortion, 1996. 11
[21]王祝伟等.渗碳模拟软件的开发.第八次全国热处理大会论文集, 2003, 5.
[22]刘群山等.热处理炉的CAD软件开发与应用.第八次全国热处理大会论文集,2003, 5.
[23]吕成等.重型燃机压气机盘淬火过程的数值模拟与优化[ J ].金属热处理, 2005增刊.
[24]张伟民等.计算机模拟在热处理工艺装备中的应用[ J ].机械工人热加工, 2005, 11.
[25]张乐福.材料科学数据库与激光表面强化计算机辅助工艺设计的研究.华中理工大学博士论文, 1997. 6.
[26] Meekisho L. Computer modeling an important tool in materials processing. Journal of Shanghai Jiaotong University,2000,E-5(1):26-34
[27]M. Gergely, S. Somogyi. Material Science Forum, 1994
[28]J. S. Kirkaldy, International conference on computers in materials technology, 1987.
[29]P. Maynier, The Materials Society AIME, New York, 1978.
[30]孙福民,徐涛,王年臣等.汽轮机热加工技术手册[M].哈尔滨汽轮机厂有限责任公司,2006.
[31]陈君若.金属物体导热、辐射和相变的耦合传热问题.力学工程.昆明:云南科技出版社,1995:115-120
[32]Denis.S, GautierE. Stress-phase-transformation-basic principles, modeling and calculation of internal stresses. Materials Science and Technology,1985,1(10):851-858
[33]潘健生,张伟民,田东等.热处理数学模型与计算机模拟.中国工程科学,2003,5(5):47-54
[34]同济大学热工教研组编.中国工业出版社出版,1961.07第一版:175-195
[35]翁中杰.传热学.上海:上海交通大学出版社,1987:10-137
[36]D.皮茨,L.西索姆.传热学.北京:科学出版社,2002:69-82
[37]A.J.查普曼.传热学.北京:冶金工业出版社,1984:156-207
[38]赵镇南.传热学.北京:高等教育出版社,2002:121-159
[39]杨世铭.传热学.北京:人民教育出版社,1981:350-358,352
[40]Y.S.Touloukian.Thermophysical Properties of Matter.IFI/plenum Press,NewYork,1970:1-453
[41]峰巢毅.数值模拟中热物性参数及组织转变的研究.日本机械学会论文集(B),1981,47(413):158-165
[42]谭真.工程合金热物性[M].冶金工业出版社,1994.09.
[43]林慧国,傅代直.钢的奥氏体转变曲线——原理、测试和应用[M].机械工业出版社,1988.02.
[44]顾剑锋.淬火应力场的模拟的研究与表面换热系数的测算[D].上海交通大学,1999.
[45]F.Liu,C.Yang,G.Yang,Y.Zhou. Additivity rule, isothermal and non-isothermal transformations on the basis of an analytical transformation model [J]. Acta Materialia, 2007 (55).
[46]P.R.Rios. Relationship between non-isothermal transformation curves and isothermal and non-isothermal kinetics [J]. Acta Materialia, 2005 (53).
[47] Christian JW. The theory of transformations in metals and alloys.2nd ed. Oxford: Pergamon Press; 1975. p. 545–6.
[48] Liu F, Sommer F, Mittemeijer EJ. Inter Mater Rev 2007 (in press).
[49] Zhu YT, Lowe TC. Metall Mater Trans B 2000;31B:675.
[50] Christian JW. In: Cahn RW, editor. Physical metallurgy. Amsterdam: North-Holland; 1977. p. 479–580.
[51] Hsu TY. Curr Opin Solid State Mater Sci 2005;9:256.
[52] Ye JS, Hsu TY, Xu Zuyao. ISIJ Int 2004;44:777.
[53] Ye JS, Chang HB, Hsu TY, Xu Zuyao. Metall Mater Trans 2003;34A:1259.
[54]蔡乔方主编.加热炉[M].机械工业出版社,2007.04.
[55]陈火红,尹伟奇,薛小香编著. MSC.Marc二次开发指南.科学出版社,2002.P385
[56]陈绍纲主编《轮机工程手册》编委会编.轮机工程手册上册.人民交通出版社, 1992.
[57]余其铮.辐射换热原理.哈尔滨工业大学出版社,2000.
[2]康打韬,叶国斌.大型锻件材料及热处理.龙门书局出版,1998:166-168
[3]刘庄.热处理过程的数值模拟.北京:科学出版社,1996:1-2,304-310
[4]崔晓龙,万妮丽.大型锻件热处理过程的数值模拟研究.鞍钢技术,2004,6:41-44
[5]王大鹏.轴对称大锻件淬火过程温度场及组织场的数值模拟.[大连理工大学硕士学位论文].2002:2-6
[6]李强.淬火过程的计算机模拟与试验研究.[燕山大学工学博士学位论文].2003:15-16
[7]Pan Jiansheng.Research and application prospect of computer simulation on heat treatment process. Journal of Shanghai Jiao tong University,2000,E-5(1):1-13
[8]Π.B.斯科柳耶夫:大型锻件中的氢与白点,机械工业出版社,1966
[9]陈德和:钢的缺陷,机械工业出版社,1966.
[10]H.D.Emmert:Inverstigationof large steam turbin splindle failure,TASME,1956,Vol,78,p1547.
[11].B.Я.杜博沃依:钢中白点,冶金工业出版社,1955.
[12]高守义.热处理有限差分法模拟研究.大连理工大学学报,1989,29(2):183-190
[13]S.W.Han.Immersion Time Quenching.Advanced Material&Processes,1995(9):42AA-42DD
[14]Neil Zuckerm an, Impingement Heat Transfer: Correlations and Numerical Modeling, Journal lf Heat Transfer, May,2005.
[15]Ferrari, An Evaluation of Gas Quenching of Steel Rings by Multiple - jet Impingement,Mater Process Techno, 2003.
[16]H. W. Walton, Heat Treatment of Metals, 1983, 1.
[17]Y. Huo, Boundary /Finite Element Modeling of Three - Dimensional Electromagnetic Heating during Microwave Food Processing, Journal of Heat Transfer, October 2005.
[18]杨卓越等.新技术新工艺, 1996, 5.
[19]K. B londeau, Heat Treatment, 1976.
[20]M. G. Palafox, Proceeding of the second International con2. ference on quenching and the control of distortion, 1996. 11
[21]王祝伟等.渗碳模拟软件的开发.第八次全国热处理大会论文集, 2003, 5.
[22]刘群山等.热处理炉的CAD软件开发与应用.第八次全国热处理大会论文集,2003, 5.
[23]吕成等.重型燃机压气机盘淬火过程的数值模拟与优化[ J ].金属热处理, 2005增刊.
[24]张伟民等.计算机模拟在热处理工艺装备中的应用[ J ].机械工人热加工, 2005, 11.
[25]张乐福.材料科学数据库与激光表面强化计算机辅助工艺设计的研究.华中理工大学博士论文, 1997. 6.
[26] Meekisho L. Computer modeling an important tool in materials processing. Journal of Shanghai Jiaotong University,2000,E-5(1):26-34
[27]M. Gergely, S. Somogyi. Material Science Forum, 1994
[28]J. S. Kirkaldy, International conference on computers in materials technology, 1987.
[29]P. Maynier, The Materials Society AIME, New York, 1978.
[30]孙福民,徐涛,王年臣等.汽轮机热加工技术手册[M].哈尔滨汽轮机厂有限责任公司,2006.
[31]陈君若.金属物体导热、辐射和相变的耦合传热问题.力学工程.昆明:云南科技出版社,1995:115-120
[32]Denis.S, GautierE. Stress-phase-transformation-basic principles, modeling and calculation of internal stresses. Materials Science and Technology,1985,1(10):851-858
[33]潘健生,张伟民,田东等.热处理数学模型与计算机模拟.中国工程科学,2003,5(5):47-54
[34]同济大学热工教研组编.中国工业出版社出版,1961.07第一版:175-195
[35]翁中杰.传热学.上海:上海交通大学出版社,1987:10-137
[36]D.皮茨,L.西索姆.传热学.北京:科学出版社,2002:69-82
[37]A.J.查普曼.传热学.北京:冶金工业出版社,1984:156-207
[38]赵镇南.传热学.北京:高等教育出版社,2002:121-159
[39]杨世铭.传热学.北京:人民教育出版社,1981:350-358,352
[40]Y.S.Touloukian.Thermophysical Properties of Matter.IFI/plenum Press,NewYork,1970:1-453
[41]峰巢毅.数值模拟中热物性参数及组织转变的研究.日本机械学会论文集(B),1981,47(413):158-165
[42]谭真.工程合金热物性[M].冶金工业出版社,1994.09.
[43]林慧国,傅代直.钢的奥氏体转变曲线——原理、测试和应用[M].机械工业出版社,1988.02.
[44]顾剑锋.淬火应力场的模拟的研究与表面换热系数的测算[D].上海交通大学,1999.
[45]F.Liu,C.Yang,G.Yang,Y.Zhou. Additivity rule, isothermal and non-isothermal transformations on the basis of an analytical transformation model [J]. Acta Materialia, 2007 (55).
[46]P.R.Rios. Relationship between non-isothermal transformation curves and isothermal and non-isothermal kinetics [J]. Acta Materialia, 2005 (53).
[47] Christian JW. The theory of transformations in metals and alloys.2nd ed. Oxford: Pergamon Press; 1975. p. 545–6.
[48] Liu F, Sommer F, Mittemeijer EJ. Inter Mater Rev 2007 (in press).
[49] Zhu YT, Lowe TC. Metall Mater Trans B 2000;31B:675.
[50] Christian JW. In: Cahn RW, editor. Physical metallurgy. Amsterdam: North-Holland; 1977. p. 479–580.
[51] Hsu TY. Curr Opin Solid State Mater Sci 2005;9:256.
[52] Ye JS, Hsu TY, Xu Zuyao. ISIJ Int 2004;44:777.
[53] Ye JS, Chang HB, Hsu TY, Xu Zuyao. Metall Mater Trans 2003;34A:1259.
[54]蔡乔方主编.加热炉[M].机械工业出版社,2007.04.
[55]陈火红,尹伟奇,薛小香编著. MSC.Marc二次开发指南.科学出版社,2002.P385
[56]陈绍纲主编《轮机工程手册》编委会编.轮机工程手册上册.人民交通出版社, 1992.
[57]余其铮.辐射换热原理.哈尔滨工业大学出版社,2000.
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