双向预置应力控制焊接变形及防止热裂纹研究
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摘要
焊接变形大和热裂敏感性高是铝合金薄板结构焊接加工中存在的较为严重的问题。基于焊接变形和热裂纹的产生都与焊接过程中的应力应变演变密切相关,本文从力学角度出发,首次提出双向预置应力控制焊接变形和防止热裂纹新工艺,同时解决了焊接变形和热裂纹问题。预置纵向拉应力控制焊接变形和降低焊接残余应力,与此同时预置横向压应力抵消焊缝金属固有的凝固收缩时受到的拉应变以及预置纵向拉应力对焊缝金属造成的额外拉应变,从而起到防止热裂纹的作用。
     采用有限元数值模拟和工艺试验相结合的研究方法,首先模拟了双向预置应力下的静力学应力应变场,然后模拟了双向预置应力作用下焊接过程中的应力演变过程和焊后残余应力。模拟结果表明了双向预置应力控制焊接变形和防止热裂纹工艺的可行性,研究了预置纵向拉应力和横向压应力这两个重要参数对其作用效果的影响以及交互作用,初步揭示了其作用机理,并为工艺试验中制定合理的工艺参数提供指导。自主设计制造了双向预置应力焊接机构,在此基础上针对尺寸为300mm×200mm×2mm的LY12CZ铝合金进行了双向预置应力焊接工艺试验。试验结果表明:预置横向压应力保持0.2σs不变时,随着预置纵向拉应力的增加,焊接挠曲变形量越来越小,从常规焊时的最大挠曲变形量的13mm下降到预置纵向拉应力为0.7σs时的2mm,同时焊接残余应力峰值从常规焊时的213.4MPa下降到41.6MPa;随着预置纵向拉应力的增加焊接热裂纹的倾向有增大的趋势,施加横向压应力能很好的解决预拉伸控制焊接变形中出现的热裂纹问题,在施加0.5σs预置纵向拉应力而无预置横向压应力时热裂纹率高达13.4%,而施加0.s预置横向压应力后基本上无宏观热裂纹的出现;预置横向压应力对焊接变形的控制也起到一定的作用,但是预置横向压应力值较小时,其作用有限;用0.6σs~0.7σs的预置纵向拉应力配合0.2σs~0.s的预置横向拉应力时,得到了低应力、小变形且无焊接热裂纹的试件。
Welding distortion and high susceptibility to hot cracking are serious problems associated with welding thin plate structures of aluminum alloys. Considering that both welding distortion and hot cracking are relative to the evolution of stress and strain in the welding process, a new technology named biaxial prestressing method is put forward to control the welding distortion and prevent welding hot cracking from the view of mechanics. The longitudinal prestressing is used to control welding distortion and reduce residual stress; at the same time exerting transverse plastic compression strain on the weld through the transverse prestressing counteracts the tensile strain which leads to hot cracking.
     Both finite element simulation and engineer testing are applied to study the problem. First of all, the static stress and strain fields which are caused by the biaxial prestressing are simulated. Then, the evolution of stress and residual stress in the welding process are simulated. The simulation result has proved the feasibility of biaxial prestressing method and has discovered the basic mechanism. Moreover, the simulation results help to establish the proper parameter of engineer testing.
     The valid equipment of biaxial prestressing method is designed and manufactured. In the welding test and study, the size of 300mm×200mm×2mm of LY12CZ aluminum alloy thin plates are employed. The conclusions above can be got from the experiment result: the maximum deflection deformation tends to decrease with the increasing of the longitudinal prestressing when the transverse prestressing is constant, the maximum deflection deformation in conventional welding is 13mm compared to the only 2mm in the biaxial prestressing method welding. At the same time, the maximum residual stress decreases from 213.4MPa to 41.6MPa. The hot cracking susceptibility is gradually increasing with the increasing longitudinal prestressing. however, The hot cracking susceptibility is gradually reduced with the increasing of the transverse prestressing, when the longitudinal prestressing is 0.5σs, the hot cracking rates is as high as 13.4% without transverse prestressing compared that there is nearly no macroscopical hot cracking when the transverse prestressing is 0.s. Transverse prestressing can also make a little effect on controlling welding distortion. When the longitudinal prestressing is about 0.6σs to 0.7σs and the transverse prestressing is about 0.2σs to 0.s, we can get the better weldment with low welding distortion and no hot cracking.
引文
1周万盛,箱材料及其焊接性.宇航材料工艺. 1986, (5):57~59
    2邱惠中.铝锂合金的发展概况及其应用.宇航材料工艺. 1993, (4):38~45
    3 T. S. Srivatsan, T. S. Sudarshan. Welding of Lightweight Aluminum-Lithium Alloys. Welding Journal. 1991, (7):173~184
    4合波,胡宗武,商伟军等.残余应力对对接接头疲劳性能的影响.机械强度. 1998, 20 (3):7~170
    5王引真,贺勇,王忠平等.热应变对2090铝锂合金焊接热影响区显微组织和力学性能的影响.材料科学与工艺. 1996, 14(3):81~85
    6第一机械工业部哈尔滨焊接研究所.焊接裂缝金相分析图谱.黑龙江科学技术出版社, 1981:1~55
    7田锡唐.焊接结构.机械工业出版社, 1982:5~16
    8 R. A. Chihoski. Expansion and Stress around Aluminum Weld Puddles. Welding Journal. 1979, (12):263s~276s
    9林德超,史耀武,蔡洪能.强度和线膨胀系数匹配对焊接残余应力的影响规律.压力容器. 1996, 13(6):27~31
    10张玉凤,霍立兴,王立君.焊缝匹配对力学性能影响的综合研究.机械工程学报. 1994, 30(3):31~38
    11魏良武.固有应变法预测焊接变形的研究及其工程应用.上海交通大学博士学位论文. 2004:58~76
    12陈积光,豆志武,赖伟栋.焊接钛制压力容器中残余应力的研究.焊接技术. 2001, 30(2):40~41
    13 C. L. Tsal, S. C. Park and W. T. Cheng. Welding Distortion of a Thin-Plate Panel Structure. Welding Journal. 1999, (5):156s~165s
    14 F. W. Bornscheuer. The Effect of Residual Welding Stresses on Buckling Strength. Rivista Italiana Della Saldatura. 1990, (3):18~25
    15 Lytle Johnson. Formation of Plastic Strain during Welding of Aluminum Alloy. Welding Journal. 1973, (7):298s~305s
    16 Jonsson, B. L. Josefson. Experimentally Determined Transient and Residual Stresses in a Butt-welded Pipe. Journal of Strain Analysis. 1988, 23(1):25~31
    17 J. Lu, C. Bouhelier and H. P. Lieurade. Study of Residual Welding StressUsing the Step-by-step Hole Drilling and X-ray Diffraction Method. Welding in The World. 1994, 33(8):118~128
    18兰春萍,张玉凤.管道结构环焊缝焊接残余应力的计算与测量.焊接技术. 1999, (4):5~6
    19王引真,贺勇,王忠平.热应变对2090铝锂合金焊接热影响区显微组织和力学性能的影响.材料科学与工艺. 1996, 4(3):81~85
    20任登义,魏星,王育福等.铸铁冷焊锤击力的测定及锤击效果分析.焊接. 1998, (1):12~15
    21邹增大,王新洪,曲仕尧.锤击消除焊接接头残余应力的数值模拟.中国机械工程. 2000, 21(2):466~468
    22夏丕旭,董亚辉,董增田.锤击法提高焊接接头疲劳强度新技术途径探讨.焊接. 1991, (12):2~6
    23 J. E. Braid, R. Bell and D. V. Militaru. Fatigue Life of As-Welded, Repaired, and Hammer-Peened Joints in High-Strength Structural Steel. Welding in the World. 1996, 37(2):248~262
    24徐文立,黎明,刘雪松等.动态低应力小变形无热裂随焊锤击焊接技术研究.材料科学与工艺. 2001, 9(1):6~10
    25徐文立,田锡唐,刘雪松.随焊锤击对LY12CZ焊接接头力学性能的影响.材料科学与工艺. 2001, 9(3):33~35
    26 Xu Wenli, Tian Xitang and Liu Xuesong. A New Method for Welding Aluminum Alloy LY12CZ Sheet with High Strength. China Welding. 2001, 10(2):121~127
    27徐文立,田锡唐,刘雪松.随焊锤击对LY12CZ焊接接头显微组织的影响.哈尔滨工业大学学报. 2001, 33(4):442~446
    28 P. Michaleris, X. Sun. Finite Element Analysis of Thermal Tensioning Techniques Mitigation Weld Buckling Distortion Residual Stress in Design, Fabrication, Assessment and Repaired. R. W. Warke. ASME PVP. 1996, 32 (7):77~79
    29 P. Michalaras. Prediction and Minimization of Welding Induced Distortion. International institute of Welding (IIW-X/XV-RSDP-10-97). Paris, 1997:95~99
    30 U. I. Birmanetal. Welding Research Abroad. 1985, (12):33~35
    31关桥,张崇显,郭德伦.动态控制的低应力无变形焊接新技术.焊接学报.1994, 15 (1):8~15
    32 L. M.洛巴诺夫.巴顿焊接研究所在结构焊接及强度领域的最新研究方向.第九次全国焊接会议论文集.北京, 1999: 48~61
    33 J. D. Tompson. Control of Distortion Due to Welding and the Additional Cost Involved. Journal of Strain Analysis. 1977, 12(2):23~28
    34孟详定.论焊接变形及防治措施.中国锅炉压力容器安全. 1998, 14(4):15~17
    35周振丰.焊接冶金与金属焊接性.机械工业出版社, 1988:190~120
    36孙维善.船舶焊接.国防工业出版社, 1986, 6:100~115
    37 N. N. Prokhorov. Problems of The Strength of Metals in the Process of Solidification during Welding. Welding Production. 1956, (6):5~11
    38水野政夫.铝及其合金的焊接.许慧姿译.冶金工业出版社, 1985:1~4
    39中国机械工程学会焊接学会编.焊接手册.第2卷(材料的焊接).机械工业出版社, 1992:496~521
    40 J. H. Dudes, F. R. Collins. Preventing Weld Cracking in High Strength Aluminum Alloys. Welding Journal. 1966, 45(6):241~249
    41 K. Nakataetal. New Al-7% Mg Welding Electrode for Crackless Welding of Al-Zn-Mg (7N01) High Strength Aluminum Alloy (Report I). Transaction of JWRI. 1980, 9(2):2~12
    42高大路,贺运佳,王引真.铈含量对2090合金焊缝结晶裂纹倾向的影响.第七届全国焊接学术会议论文集(第四册).青岛, 1993:295~299
    43张文钺,魏祚伟. 8090铝锂合金焊接热裂纹敏感性的研究.焊接. 1992, (3):8~12
    44凌泽民.含稀土钇的LY12CZ焊接接头热裂纹和应力腐蚀开裂性能.哈尔滨工业大学硕士论文. 1988:46~51
    45卢烨等.磁控电弧摆动对铝合金焊缝结晶裂纹的影响.焊接学报. 1991, 12(2):65~71
    46 Kou, Y. Le. Improving Weld Quality by Low Frequency Arc Oscillation. Welding Journal. 1985, 64(3):51~55
    47 Kou, Y. Le. Alternating Grain Orientation and Weld Solidification Cracking. Metallurgical Transactions A. 1985, 16A(10):1887~1896
    48 J. C. Borland. Fundamentals of Solidification Cracking in Welds. Welding and Metal Fabrication. 1979, (3):100~107
    49 Carlson. Mathematical Models Approximating Butt Welding Process Cause and Prevention of Hot Cracking. Proceedings of the International Conference, II W-X-806-76. Tokyo, 2006:59~68
    50 Koichi, Masubuchi. Research Activities Examine Residual Stresses and Distortion in Welded Structures. Welding Journal. 1991, (12):41~46
    51 H. Sekiguchi and H. Miyake. Prevention of Welding Cracks through a Local Heating Process. Transactions of the Japan Welding Society 1975, 6(1):53~58
    52 I. E. Hemandez, T. H. North. The Influence of External Local Heating in Preventing Cracking during Welding of Aluminum Alloy Sheet. Welding Journal 1984, 63 (3):84s~90s
    53吴爱萍. Cr-Ni奥氏体钢焊缝凝固时冶金-力学行为与凝固裂纹的研究.清华大学博士论文. 1994:24~36
    54田锡唐,杨愉平,张忠.随焊激冷防止焊接热裂纹新方法的研究.材料科学与工艺. 1994, 2(1): 69~73
    55王者昌.高强铝合金焊接热裂纹控制.第七届全国焊接学术会议论文集.北京, 1993:295~299
    56刘伟平,田锡唐,张修智.一种防止高强铝合金焊接热裂纹产生的新方法.焊接学报. 1995, 16(2):106~111
    57徐文立,田锡唐.随焊锤击防止高强铝合金薄板焊接热裂纹的研究.第十次全国焊接会议论文集. 2001:221~224
    58方洪渊,董志波,徐文立.随焊锤击防止薄板焊接热裂纹的工艺.焊接. 2002, (3):17~20
    59 Level. Tension of welded butt edges as a means of preventing distortion in thin sheets. Trudy TsNIIRechFIot. 1955, (31):87~100
    60 Xu Wenli, Fang Hongyuan. New development in welding thin shell aluminum alloy structure with high strength. China Welding. 2004, 13 (1):27~30
    61 L. Tall. The Calculation of Residual Stresses in Perspective. Residua Stress in Welded Construction and the Effects. International Conference London, 1977, 7:49~62
    62 L. M.洛巴诺夫.巴顿焊接研究所在结构焊接及强度领域的最新研究方向.第九次全国焊接会议论文集,第1册.黑龙江人民出版社, 1999:48~61
    63 Lobanov, Pavlovsky and Lysak. Elastic pretension in aluminum alloy sheetwelding. Schweisstechnik (Berlin), 1987(10):447~449
    64潘华.机械拉伸控制A3钢板壳结构的变形.哈尔滨工业大学硕士论文. 2000:11~26
    65章明明.预拉伸对铝合金焊接残余应力和变形的影响.热加工工艺. 2005(12):15~17

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