平行剪切中设计参数对剪切性能的影响研究
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摘要
中厚钢板是国家制造业中必不可少的重要钢铁材料,是国民经济发展过程中重要的钢铁品种。随着我国对中厚钢板的需求逐年提高,对设备的生产效率要求也大幅上涨。轧钢整形生产线中极为重要的一步就是按指定尺寸切边。板材的剪切加工最简单,应用也最广。而目前在生产实践中,剪切机工作时经常出现的各种连刀、堵边、切不动等生产故障大都是由剪切参数的设置不当所导致。由于板材的剪切加工过程中材料的变形集中在很小的区域内,且以断裂方式告终,使这一过程非常复杂。目前我国在剪切设计参数特别是剪切间隙对剪切质量的理论研究一般停留在相对粗糙的阶段,制约了生产的发展。因此,与之对应的应用理论研究,也显得越来越重要和紧迫。
本文从重庆钢铁集团带钢生产线上采用的滚筒式碎边剪切机自投产后固定侧减速箱箱体频繁破坏、钢边切不断、剪刃崩坏的情况出发,通过实验推断出剪切扭矩过大是导致破坏的主要原因,然后对重钢采用的碎边剪建立了相应的理论模型,认为导致剪切力扭矩过大的主要原因是由剪切间隙设置不当导致的剪切力峰值过大。指出选取合适的剪切间隙是剪切效果的关键因素。
本文将复杂的剪切变形过程从微观变形形式以及断裂形式上与简单的拉伸变形、弯曲变形进行比较。在对剪切问题进行必要的简化后,利用复合-分解的原理,分析剪切变形的应力分布及特性。为了提取后续分析需要的信息,提出通过常用材料力能参数简化模拟拉伸曲线的方法。
然后本文通过建立剪切间隙分析与应力-应变曲线之间的关系来反映其对于剪切性能的影响。分别从与剪切力峰值的关系和与剪切断面质量的关系两个角度入手。研究前者时,先从宏观角度分析相对间隙和切深对轧件转角的影响,再联合微观剪切强度理论,探讨相对间隙与剪切力峰值间的定量关系。研究后者时,选择分阶段分别研究剪切间隙对剪切断面特征带分布中圆角带、光亮带、断裂带的影响。对于圆角带,结合体积不变原理和几何关系分析,建立剪切间隙与圆角带高度间的定量关系。对于光亮带,基于前文中建立的剪切与拉伸应力应变曲线间的关系,被分为压入阶段带和滑移阶段带两个部分,分别建立其高度与相对间隙及材料性能参数之间的定量关系式。对于断裂带,则通过对裂纹萌生关键点的应力状态分析求解最大剪应力方向来探讨剪切间隙对裂纹萌生方向的影响。而后综上提出保证上下裂纹相遇和降低剪切能耗两种侧重点不同的间隙设计方法。
此外本文还对于刀刃参数和轧件尺寸参数对于剪切效果的影响做了综述性探讨。前者以分析刀刃倾斜角以及锐利度对于剪切力的影响为主。后者则侧重于探讨尺寸参数对于断裂情况的影响来体现对于剪切效果的影响。随后本文采用两组剪切应力-应变实验曲线对前文中关于相对间隙、材料性能参数和剪切曲线切深特征值的之间的关系式进行了验证。
理论分析表明,板材剪切加工涉及到很多复杂问题,通过分析剪切加工过程中的变形机理和裂纹扩展机制,简化研究关键工艺参数剪切间隙来预测或控制剪切时的受力峰值及剪切件的断面特征,有助于提高剪切质量,改善剪切性能。对相关问题还需要作许多深入细致的工作。
In recent years, the medium-thick steel plate production has keeping on increasing,With the improvement of the plate cut quality, the production efficiency of scrap chopper was proposed higher requirements. At present in producing practice,the majority troubles such as cut vibration or blocking cut usually because of the unsuitable shear parameter especially the shear clearance. However,most of the technologies of, shear production were introduced from abroad. The foreign technical protection and little independent research lead to blank on the precise relationship between shear clearance and plate cut quality. Therefore,make a research on this subject is very important and necessary.
In this paper,the action origin in the production difficulty from Chongqing Iron&Steel Company Limited that the reduction gearbox of chopper shear broken every three months.Through the experiment,the main reason is the unsuitable shearing clearance.Then based on cutting principle,finished some research on the relationship between shearing clearance and the characteristics of the fracture. Built on the physics and math model of the cutting process considering the influence of shearing stress.Provide some functions to find out the suitable clearance,to help highlight the quality.
On purpose to analyze how the shear clearance influence plate cut quality,this paper put tensile and shear stress-strain curve and shear zone in one combine.First,compared the shear stress-strain curve with the tensile stress-strain,then built a simple model which can get the characteristic value.Then mapped the shear zone onto the shear stress-strain curve.The bright belt of the cross section was separated into two parts,the former one together with fillet belt belonged to the cut-in session,the latter one belonged to the slip session.With the strain compute by the simple tensile stress-strain model,the connection between relative shear clearance,mechanical properties of material and shear zone was figured out.Then used the balance of force to get the relationship between relative shear clearance and rotating angle of and the ratio of shear stress and lateral pressure.According to the fault zone,through analyzing plane-stress state,the direction of the maximum shear stress can be done.Depend on the research above,the methods to design the relative shear clearance were brought up.
Apart from these,this paper also talked about two other influence elements which were the blade and the size of the steel.The blade could improve the late cut quality by means of keeping sharp and reduce the shear stress by incline a little angle from the vertical position.And both the thickness and highness of the steel would make a change to the fracture form. Finally, two examples illustrated that the relationship shear stress-strain curve and relative shear clearance,mechanical properties of material was improved.
The design method of shear clearance in this paper is general, and can be extended to a series of similar products design. And it is significant for our country's shear device independent research and development.
本文从重庆钢铁集团带钢生产线上采用的滚筒式碎边剪切机自投产后固定侧减速箱箱体频繁破坏、钢边切不断、剪刃崩坏的情况出发,通过实验推断出剪切扭矩过大是导致破坏的主要原因,然后对重钢采用的碎边剪建立了相应的理论模型,认为导致剪切力扭矩过大的主要原因是由剪切间隙设置不当导致的剪切力峰值过大。指出选取合适的剪切间隙是剪切效果的关键因素。
本文将复杂的剪切变形过程从微观变形形式以及断裂形式上与简单的拉伸变形、弯曲变形进行比较。在对剪切问题进行必要的简化后,利用复合-分解的原理,分析剪切变形的应力分布及特性。为了提取后续分析需要的信息,提出通过常用材料力能参数简化模拟拉伸曲线的方法。
然后本文通过建立剪切间隙分析与应力-应变曲线之间的关系来反映其对于剪切性能的影响。分别从与剪切力峰值的关系和与剪切断面质量的关系两个角度入手。研究前者时,先从宏观角度分析相对间隙和切深对轧件转角的影响,再联合微观剪切强度理论,探讨相对间隙与剪切力峰值间的定量关系。研究后者时,选择分阶段分别研究剪切间隙对剪切断面特征带分布中圆角带、光亮带、断裂带的影响。对于圆角带,结合体积不变原理和几何关系分析,建立剪切间隙与圆角带高度间的定量关系。对于光亮带,基于前文中建立的剪切与拉伸应力应变曲线间的关系,被分为压入阶段带和滑移阶段带两个部分,分别建立其高度与相对间隙及材料性能参数之间的定量关系式。对于断裂带,则通过对裂纹萌生关键点的应力状态分析求解最大剪应力方向来探讨剪切间隙对裂纹萌生方向的影响。而后综上提出保证上下裂纹相遇和降低剪切能耗两种侧重点不同的间隙设计方法。
此外本文还对于刀刃参数和轧件尺寸参数对于剪切效果的影响做了综述性探讨。前者以分析刀刃倾斜角以及锐利度对于剪切力的影响为主。后者则侧重于探讨尺寸参数对于断裂情况的影响来体现对于剪切效果的影响。随后本文采用两组剪切应力-应变实验曲线对前文中关于相对间隙、材料性能参数和剪切曲线切深特征值的之间的关系式进行了验证。
理论分析表明,板材剪切加工涉及到很多复杂问题,通过分析剪切加工过程中的变形机理和裂纹扩展机制,简化研究关键工艺参数剪切间隙来预测或控制剪切时的受力峰值及剪切件的断面特征,有助于提高剪切质量,改善剪切性能。对相关问题还需要作许多深入细致的工作。
In recent years, the medium-thick steel plate production has keeping on increasing,With the improvement of the plate cut quality, the production efficiency of scrap chopper was proposed higher requirements. At present in producing practice,the majority troubles such as cut vibration or blocking cut usually because of the unsuitable shear parameter especially the shear clearance. However,most of the technologies of, shear production were introduced from abroad. The foreign technical protection and little independent research lead to blank on the precise relationship between shear clearance and plate cut quality. Therefore,make a research on this subject is very important and necessary.
In this paper,the action origin in the production difficulty from Chongqing Iron&Steel Company Limited that the reduction gearbox of chopper shear broken every three months.Through the experiment,the main reason is the unsuitable shearing clearance.Then based on cutting principle,finished some research on the relationship between shearing clearance and the characteristics of the fracture. Built on the physics and math model of the cutting process considering the influence of shearing stress.Provide some functions to find out the suitable clearance,to help highlight the quality.
On purpose to analyze how the shear clearance influence plate cut quality,this paper put tensile and shear stress-strain curve and shear zone in one combine.First,compared the shear stress-strain curve with the tensile stress-strain,then built a simple model which can get the characteristic value.Then mapped the shear zone onto the shear stress-strain curve.The bright belt of the cross section was separated into two parts,the former one together with fillet belt belonged to the cut-in session,the latter one belonged to the slip session.With the strain compute by the simple tensile stress-strain model,the connection between relative shear clearance,mechanical properties of material and shear zone was figured out.Then used the balance of force to get the relationship between relative shear clearance and rotating angle of and the ratio of shear stress and lateral pressure.According to the fault zone,through analyzing plane-stress state,the direction of the maximum shear stress can be done.Depend on the research above,the methods to design the relative shear clearance were brought up.
Apart from these,this paper also talked about two other influence elements which were the blade and the size of the steel.The blade could improve the late cut quality by means of keeping sharp and reduce the shear stress by incline a little angle from the vertical position.And both the thickness and highness of the steel would make a change to the fracture form. Finally, two examples illustrated that the relationship shear stress-strain curve and relative shear clearance,mechanical properties of material was improved.
The design method of shear clearance in this paper is general, and can be extended to a series of similar products design. And it is significant for our country's shear device independent research and development.
引文
[1]邹家祥.轧钢机械[G].北京：冶金工业出版社,2002.
[2]周望生,罗晓玉,段明南.热轧精整线圆盘剪剪切能力的分析研究及设备改造[J].冶金设备,2008(01)：29-33.
[3]李瑛.浅析滚切剪在中厚板厂的应用[J].冶金标准化与质量,2007(05)：53-55.
[4]庞先进,杨俊益,牛国林,等.圆盘剪卡钢的因素分析及措施[J].河南冶金,2004(03)：42-43.
[5]张向葵.影响厚板剪切质量因素及改进方法初探[J].宝钢技术,2006(04)：23-26.
[6]李雷生,秦立学,赵国彬,等.滚切剪特点及关键参数分析[J].科技资讯,2008(24)：48-49.
[7]寇传乾.双边剪控制系统的设计与应用[J].电气时代,2004(03)：60-61.
[8]John. C. Holdgate, William. P. Donald, Donald. A. McArthur. Scrap Chopper for Edge Trimming Shears:American, Ohio,273696[P].1939,05,15.
[9]Ernest. Robert. Bodnar. Scrap Chopper:Canada, Ontario,547365[P].1977,01,25.
[10]Herbert. M. Hill, Donald. R. Shrader. Apparatus for Chopping Scrap Strip Material into small pieces:American, Ohio,201340[P].1982,12,14.
[11]John.Robert. Buta,. Dual Arbor Scrap Chopper:American, Ohio,15425[P].1989,08,22.
[12]赵瑞迎,马承国.可调节重叠量的碎边剪装置[P].宝山钢铁股份有限公司,2006.
[13]杨俊益.碎边剪剪切缺陷的产生原因及改进[J].轧钢,2002(01)：63-64.
[14]杨俊益.优化厚规格钢板剪切工艺[J].宽厚板,2002(04)：24-26.
[15]刘建磊.提高钢板剪切精度[J].宽厚板,2002(01)：22-24.
[16]王存志,欧阳克诚.wS型碎边剪述评[J].冶金设备,2002,135(05)：9,16.
[17]莫韶斌,李全汉.双边剪夹送装置的调整[J].宽厚板,2001(04)：26-29.
[18]陈祥生.新型双滚筒式碎边剪的特点及主要结构参数的选择[J].重型机械,1988(03)：25-31.
[19]赵振彦,刘岩.1400轧机双滚筒式斜刃碎边剪性能分析[J].有色设备,1993(05)：16-21.
[20]何汝迎.酸洗机组碎边剪设计更改方案探讨[J].宝钢技术,1994(05)：53-57.
[21]薛培.新型碎边剪力能参数的分析确定[J].冶金设备,1992(05)：6-11.
[22]侯中勇,王景新,王辉,等冷轧碎边剪间隙调整传动误差的分析与补偿.中国金属学会冶金设备设计学术交流会,中国北京,2009[C]：72-78.
[23]张永祥.剪切机最佳剪切间隙的研究[J].海军工程学院学报,1995,70(01)：49-52.
[24]刘涵.中厚板轧线技术分析及创新方案研究[D].重庆：重庆大学机械学院,2006
[25]赵振彦,刘岩.1400轧机双滚筒式斜刃碎边剪性能分析[J].有色设备,1993(05)：16-21.
[26]杨固川,向健康等.大型宽厚板轧机成套装备设计制造技术评析[J].轧钢,2007(05)：38-40.
[27]刘建磊.提高钢板剪切精度[J].宽厚板,2002(01)：22-24.
[28]韦桂郁.酸洗机组的拖动圆盘剪和飞剪式碎边剪介绍[J].冶金设备,1985(01)：38-41.
[29]赵振彦,刘岩.新型碎边机剪刃特点的研究[J].机械工程师,1993(05)：7-8.
[30]R.w.赫次伯格.工程材料的变形与断裂力学[G].北京：机械工业出版社,1982.
[31]金尚年,马永利.理论力学[G].北京：高等教育出版社,2002.
[32]崔风平,孙玮,刘彦春.中厚板生产与质量控制[G].北京：冶金工业出版社,2008.
[33]王永廉.材料力学[G].北京：机械工业出版社,2011.
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[36]Allingham. L. R. Importance of Clearance in Manufacture of Blanking Dies [C].ASTME 32nd Annual Meeting-Collected Papers,Vol 64,Book4,1964:615-622
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[39]刘建磊.提高钢板剪切精度[J].宽厚板,2002(01)：22-24
[2]周望生,罗晓玉,段明南.热轧精整线圆盘剪剪切能力的分析研究及设备改造[J].冶金设备,2008(01)：29-33.
[3]李瑛.浅析滚切剪在中厚板厂的应用[J].冶金标准化与质量,2007(05)：53-55.
[4]庞先进,杨俊益,牛国林,等.圆盘剪卡钢的因素分析及措施[J].河南冶金,2004(03)：42-43.
[5]张向葵.影响厚板剪切质量因素及改进方法初探[J].宝钢技术,2006(04)：23-26.
[6]李雷生,秦立学,赵国彬,等.滚切剪特点及关键参数分析[J].科技资讯,2008(24)：48-49.
[7]寇传乾.双边剪控制系统的设计与应用[J].电气时代,2004(03)：60-61.
[8]John. C. Holdgate, William. P. Donald, Donald. A. McArthur. Scrap Chopper for Edge Trimming Shears:American, Ohio,273696[P].1939,05,15.
[9]Ernest. Robert. Bodnar. Scrap Chopper:Canada, Ontario,547365[P].1977,01,25.
[10]Herbert. M. Hill, Donald. R. Shrader. Apparatus for Chopping Scrap Strip Material into small pieces:American, Ohio,201340[P].1982,12,14.
[11]John.Robert. Buta,. Dual Arbor Scrap Chopper:American, Ohio,15425[P].1989,08,22.
[12]赵瑞迎,马承国.可调节重叠量的碎边剪装置[P].宝山钢铁股份有限公司,2006.
[13]杨俊益.碎边剪剪切缺陷的产生原因及改进[J].轧钢,2002(01)：63-64.
[14]杨俊益.优化厚规格钢板剪切工艺[J].宽厚板,2002(04)：24-26.
[15]刘建磊.提高钢板剪切精度[J].宽厚板,2002(01)：22-24.
[16]王存志,欧阳克诚.wS型碎边剪述评[J].冶金设备,2002,135(05)：9,16.
[17]莫韶斌,李全汉.双边剪夹送装置的调整[J].宽厚板,2001(04)：26-29.
[18]陈祥生.新型双滚筒式碎边剪的特点及主要结构参数的选择[J].重型机械,1988(03)：25-31.
[19]赵振彦,刘岩.1400轧机双滚筒式斜刃碎边剪性能分析[J].有色设备,1993(05)：16-21.
[20]何汝迎.酸洗机组碎边剪设计更改方案探讨[J].宝钢技术,1994(05)：53-57.
[21]薛培.新型碎边剪力能参数的分析确定[J].冶金设备,1992(05)：6-11.
[22]侯中勇,王景新,王辉,等冷轧碎边剪间隙调整传动误差的分析与补偿.中国金属学会冶金设备设计学术交流会,中国北京,2009[C]：72-78.
[23]张永祥.剪切机最佳剪切间隙的研究[J].海军工程学院学报,1995,70(01)：49-52.
[24]刘涵.中厚板轧线技术分析及创新方案研究[D].重庆：重庆大学机械学院,2006
[25]赵振彦,刘岩.1400轧机双滚筒式斜刃碎边剪性能分析[J].有色设备,1993(05)：16-21.
[26]杨固川,向健康等.大型宽厚板轧机成套装备设计制造技术评析[J].轧钢,2007(05)：38-40.
[27]刘建磊.提高钢板剪切精度[J].宽厚板,2002(01)：22-24.
[28]韦桂郁.酸洗机组的拖动圆盘剪和飞剪式碎边剪介绍[J].冶金设备,1985(01)：38-41.
[29]赵振彦,刘岩.新型碎边机剪刃特点的研究[J].机械工程师,1993(05)：7-8.
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