中国激光, 2011, 38 (4): 0403001, 网络出版: 2011-03-24   

殷瓦薄板高速激光焊接的热裂纹敏感性

Hot Tearing Susceptibility of High Speed Laser Welding Invar Sheet
作者单位
上海交通大学上海市激光制造与材料改性重点实验室, 上海 200240
摘要
以2.2 m/min激光扫描速度,采用对接和搭接两种方式高速焊接0.7 mm薄板殷瓦合金。借助金相显微镜和扫描电子显微镜观察焊缝显微组织,讨论焊缝中心的热裂纹形成机理,对比分析不同接头形式的热裂纹敏感性。实验结果显示,殷瓦合金的高速激光焊缝为铸态单相奥氏体树枝晶。对接焊缝中心出现热裂纹,而搭接焊缝未发现热裂纹。分析认为,在树枝晶凝固最后阶段,焊缝两侧树枝晶粒的大角度晶界能γgb大于2倍液态薄膜固/液界面能γsl,液态薄膜完全桥接需要临界过冷度ΔTb。殷瓦合金散热系数低,过冷度不足,焊接残余拉伸应力δr将导致液态薄膜开裂。对接时容易出现热裂纹。而搭接时开裂的液态薄膜有上层液态金属流入补充,能有效降低焊缝的热裂纹敏感性。
Abstract
0.7 mm thickness invar alloy sheet is welded at 2.2 m/min laser scanning speed by using butt and lap joint. Microstructure analysis is conducted by optical microscope and scanning electric microscope. Hot tearing mechanism and susceptibility of butt and lap joint are discussed, respectively. Results show that the weld metal is composed of as-cast single phase dendrite austenite. Some hot tearing is in the weld center of butt joint, but none is in the lap joint. At the last solidifying stage of impinging dendrite, generally, dendrite grain boundary energy γgb is always two times larger than liquid/solid interfacial energy γsl of liquid film. The liquid film coalescence will not occur until adequate undercooling ΔTb, which results in hot tearing of butt joint under welding residual tensile stress. However, the remained liquid of upper weld pool can flow down and fill into torn liquid film, then lap joint has a lower hot tearing susceptibility.
参考文献

[1] 陆建生, 沈黎明. Fe-36Ni殷瓦合金研究进展[J]. 功能材料, 2004, 35(z1): 3424~3427

    Lu Jiansheng, Shen Liming. Advances in Fe-36Ni invar alloy[J]. Journal of Functional Materials Contents, 2004, 35(z1): 3424~3427

[2] . A. Tseng, J. Müller, Y. H. Hahn. Mechanical and bending characteristics of invar sheets[J]. Materials & Design, 1996, 17(2): 89-96.

[3] A. Vinogradov, S. Hashimoto, V. I. Kopylov. Enhanced strength and fatigue life of ultra-fine grain Fe-36Ni invar alloy[J]. Materials Science and Engineering A, 2003, 355(1-2): 277~285

[4] . L. Corbacho, J. C. Suárez, F. Molleda. Grain coarsening and boundary migration during welding of invar Fe-36Ni alloy[J]. Materials Characterization, 1998, 41(1): 27-34.

[5] . Nishimoto, K. Saida, H. Okauchi et al.. Microcracking in multipass weld metal of alloy 690 Part 2-Microcracking mechanism in reheated weld metal[J]. Science and Technology of Welding & Joining, 2006, 11(4): 462-470.

[6] Peiquan Xu, Chen Huang, Jianping He. Study on temperature field for invar alloy during TIG welding[J]. The International Journal of Advanced Manufacturing Technology, 2009, 42(3-4): 242~249

[7] . Q. Xu, X. J. Zhao. Analysis of microstructure and properties of cemented carbide and invar alloy weldment[J]. Journal of Materials Engineering and Performance, 2010, 19(2): 294-300.

[8] 吴世凯, 肖荣诗, 陈铠. 大厚度不锈钢板的激光焊接[J]. 中国激光, 2009, 36(9): 2422~2425

    Wu Shikai, Xiao Rongshi, Chen Kai. Laser welding of heavy section stainless steel plants[J]. Chinese J. Lasers, 2009, 36(9): 2422~2425

[9] 李俐群, 陈彦宾, 陶汪. 铝合金双光束焊接特性研究[J]. 中国激光, 2008, 35(11): 1783~1788

    Li Liqun, Chen Yanbin, Tao Wang. Research on dual-beam welding characteristics of aluminum alloy[J]. Chinese J. Lasers, 2008, 35(11): 1783~1788

[10] 董长胜, 钟敏霖, 郝倩 等. 面向核设施晶间应力腐蚀的高Cr含量Inconel 690激光熔覆研究[J]. 中国激光, 2009, 36(12): 3256~3261

    Dong Changsheng, Zhong Minlin, Hao Qian et al.. High chromium coatings by laser deposition of inconel 690 for repairing nuclear power plant components[J]. Chinese J. Lasers, 2009, 36(12): 3256~3261

[11] 吴东江, 尹波, 张维哲 等. NdYAG激光焊接殷钢材料的工艺研究[J]. 中国激光, 2008, 35(11): 1773~1777

    Wu Dongjiang, Yin Bo, Zhang Weizhe et al.. NdYAG laser beam welding invar36 alloy[J]. Chinese J. Lasers, 2008, 35(11): 1773~1777

[12] . W. Rutter, B. Chalmers. A prismatic substructure formed during solidification of metals[J]. Canadian Journal of Physics, 1953, 31(1): 15-39.

[13] . E. Witherell. Welding nickel-iron alloys of the invar type[J]. Welding Journal, 1964, 43(4): 161-169.

[14] . Ogawa. Weldability of invar and its large-diameter pipe[J]. Welding Journal, 1986, 65(8): 213-226.

[15] . Rappaz, A. Jacot, W. J. Boettinger. Last-stage solidification of alloys: theoretical model of dendrite-arm and grain coalescence[J]. Metallurgical and Materials Transactions A, 2003, 34(3): 467-479.

[16] . D′Souza, H. B. Dong. Solidification path in third-generation Ni-based superalloys, with an emphasis on last stage solidification[J]. Scripta Materialia, 2007, 56(1): 41-44.

倪加明, 李铸国, 吴毅雄. 殷瓦薄板高速激光焊接的热裂纹敏感性[J]. 中国激光, 2011, 38(4): 0403001. Ni Jiaming, Li Zhuguo, Wu Yixiong. Hot Tearing Susceptibility of High Speed Laser Welding Invar Sheet[J]. Chinese Journal of Lasers, 2011, 38(4): 0403001.

本文已被 1 篇论文引用
被引统计数据来源于中国光学期刊网
引用该论文: TXT   |   EndNote

相关论文

加载中...

关于本站 Cookie 的使用提示

中国光学期刊网使用基于 cookie 的技术来更好地为您提供各项服务,点击此处了解我们的隐私策略。 如您需继续使用本网站,请您授权我们使用本地 cookie 来保存部分信息。
全站搜索
您最值得信赖的光电行业旗舰网络服务平台!