激光包覆焊接制备复合层研究.pdf

硕士学位论文 激光包覆焊接制备复合层研究 Research of Laser Package Welding for Preparing Welding Compound Layer 作 者郭跃 导 师樊宇 副教授 中国矿业大学 二〇一七年六月 万方数据 中图分类号 TG456.7 学校代码 10290 UDC 620 密 级 公 开 中国矿业大学 硕士学位论文 激光包覆焊接制备复合层研究 Research of Laser Package Welding for Preparing Welding Compound Layer 作 者 郭跃 导 师 樊宇 申请学位 工学硕士 培养单位 材料学院 学科专业 材料加工工程 研究方向 激光焊接 答辩委员会主席 评 阅 人 二○一七年六月 万方数据 学位论文使用授权声明学位论文使用授权声明 本人完全了解中国矿业大学有关保留、使用学位论文的规定，同意本人所撰 写的学位论文的使用授权按照学校的管理规定处理 作为申请学位的条件之一， 学位论文著作权拥有者须授权所在学校拥有学位 论文的部分使用权，即①学校档案馆和图书馆有权保留学位论文的纸质版和电 子版，可以使用影印、缩印或扫描等复制手段保存和汇编学位论文；②为教学和 科研目的，学校档案馆和图书馆可以将公开的学位论文作为资料在档案馆、图书 馆等场所或在校园网上供校内师生阅读、浏览。另外，根据有关法规，同意中国 国家图书馆保存研究生学位论文。 （保密的学位论文在解密后适用本授权书）。 作者签名 导师签名 年 月 日 年 月 日 万方数据 致谢致谢 本论文是在樊宇老师的悉心指导下完成的。樊宇老师严谨的学术态度，踏实 的工作作风， 渊博的学识， 开拓创新的精神给我留下了深刻的印象。 研究生期间， 樊宇老师的教导给我带来了很大的影响。在学业方面，加强了我发现问题以及解 决问题的能力；在生活方面，教会了我许多为人处世的道理，锻炼了我的社交能 力。在论文完成之际，谨向樊宇老师致以崇高的敬意和最诚挚的感谢。 感谢我的师弟李沛智、陈昆帮助我完成毕业论文的试验，很开心能认识你们 并成为朋友，这几年相互协作，共同奋斗的日子是我的宝贵财富。 感谢 618 宿舍的舍友张勇，常远，刘念祖，王章，张腾飞，付云充，严伟以 及 401 工作室的李朋朋、梁涛、刘建阳、刘鹏福、乐婷莲、乔磊、冯梁成，张跃 等对我生活和学习的帮助，没有你们的帮助我的试验不可能顺利完成。 感谢材料学院 14 级全体研究生，很高兴能和你们共同走过这三年的研究生 生涯，我们的友谊长存。 感谢我的家人对我学业的支持，你们的关怀和鼓励是我一直前进的动力。 最后衷心的感谢诸位评审专家在百忙之中评审我的论文， 并真诚的希望能够 得到各位专家的指点与教导。 万方数据 I 摘摘 要要 立柱是液压支架设备中的易损件， 煤矿严重的腐蚀环境直接影响着立柱的使 用寿命，容易出现磨损、腐蚀、变形等现象，从而导致液压系统失效，因此，要 对立柱表面进行处理。传统的表面处理方法为电镀、化学镀和激光熔覆，前者容 易产生含重金属离子的电镀废水和各类酸雾废气，污染严重，后者使用的熔覆合 金粉末制作成本高、周期长，且增加空气中会悬浮颗粒物，本文首次提出用激光 包覆焊接代替激光熔覆，以薄板带材代替粉末，对立柱表面进行处理。 本文首先以 304 不锈钢和 27SiMn 钢为研究对象，对其进行单道激光搭接焊 和激光包覆焊，通过光学显微镜、扫描电镜、X 射线衍射分析仪、磨损试验机以 及电化学测试站，研究焊缝的凝固模式、工艺参数对焊缝形貌的影响以及所制备 焊接复合层的耐磨性和耐腐蚀性，然后再以 Inconel 718 合金代替 304 不锈钢进 行包覆焊制备复合层， 对比两种复合层的耐磨性和耐腐蚀性。 研究结果如下 304 不锈钢焊缝的边缘为柱状晶，中心为等轴晶，室温下的组织为铁素体和奥氏体； 27SiMn 钢焊缝的中心组织以板条状的马氏体为主，热影响区组织为马氏体和贝 氏体；两种材料进行搭接焊时，获得了良好的冶金结合，焊缝过渡区组织为马氏 体、铁素体和奥氏体，304 不锈钢母材的平均显微硬度约为 178.1 HV，焊缝的平 均硬度为 279.4 HV，27SiMn 钢母材的平均显微硬度约为 260.1 HV，焊缝的平均 显微硬度约为 392.9 HV。 不同工艺参数均能获得平整、光滑、致密的焊缝。随着激光功率的增加，焊 缝的熔深、熔宽以及硬度值均增大；随着焊接速度的增加，焊缝的熔深、熔宽减 小，焊接速度的变化对焊缝的硬度影响不大；焊缝熔深和硬度均随离焦量的变化 先增加后减小，而对熔宽的影响较小，各工艺参数下焊缝的束腰高和束腰宽均变 化不大。 在不同的激光功率、焊接速度、离焦量以及搭接率下，均能获得成形良好的 304 不锈钢/27SiMn 钢复合层；在激光功率 400 W、焊接速度 0.8 m/min、离焦量 0 mm 以及搭接 60的工艺参数下， 复合层的磨损量最小； 对 304 不锈钢/27SiMn 钢复合层进行电化学测试并与 304 不锈钢母材进行比较， 复合层的耐腐蚀性略差 于 304 不锈钢母材。 对 Inconel 718 合金和 27SiMn 钢进行激光包覆焊制备复合层， 其表面硬度值 是 304 不锈钢/27SiMn 钢复合层的 1.74 倍，磨损量也仅为 304 不锈钢/27SiMn 钢 焊复合层的 65，但耐腐蚀性能略差于 304 不锈钢/27SiMn 钢复合层。 本论文有图 37 幅，表 18 个，参考文献 91 篇。 关键词关键词激光焊接；304 不锈钢；Inconel 718 合金；复合层；磨损性；腐蚀性 万方数据 II Abstract Hydraulic column plays the significant role in supporting and bearing the pressure of the coal seam. However, the harsh environment in the mine have seriously damaged the usage of hydraulic column, corroding the surface of the hydraulic column and making them unusable. Therefore, the surface of the column surface has to be treated before using. Traditional surface treatment s are electroplating, electroless plating and laser cladding. However, the er is easy to produce electroplating waste water, which contains heavy metal ions and all kinds of acid mist exhaust, seriously polluting environmental. And the manufacture of laser cladding alloy powder is costly and difficult, also it will increase the air suspended particles. So, in this paper, it puts forward a new to deal with the pillar surface, by using laser welding instead of laser cladding, thin strip instead of powder. In this paper, based on 304 stainless steel and 27SiMn steel as the research object, it carries on the single channel laser lap welding and multi-channel laser lap welding to research the weld solidification model, the influence of process parameters on weld appearance and the preparation of welding the wear resistance and corrosion resistance of compound layer. And then using Inconel 718 alloy instead of 304 stainless steel welding to prepare the welding compound layer, compared to the two welding compound layer with wear resistance and corrosion resistance, the results are as follows the edge of the 304 stainless weld are columnar crystal, appear to weld the center is equiaxial crystal, the organization at room temperature are ferrite and austenite; the microstructure of 27SiMn steel weld center is board strips martensite, heat affected zone are martensite and bainite. It obtains good metallurgical bonding by welding the two materials and the microstructure in weld transition zone are martensite and ferrite and austenite. The average microhardness of 304 stainless steel parent metal is about 178.1 HV and the weld hardness increase to 279.4 HV, the microhardness for 27SiMn steel is about 260.1 HV and weld the average microhardness rise to 392.9 HV. In the condition of different laser power, welding speed, defocusing distances, it can obtain good-quality weld bead. With the increase of laser power, the bead penetration and bead width, but the waist width and waist depth have no obvious change. The average microhardness of weld seam increases with the laser power. With the increase of welding speed, the weld width and depth of molten decreases, and the influence of welding speed to fusion width change is close to linear equation. Under 万方数据 III different welding speed, average microhardness of weld seam doesn’t change a lot. Under the condition of different defocusing distance, the weld seam are smooth and uni density without cracks, subsidence and bite edge. The penetration depth and bead width firstly increase and then decreases with the change of defocusing distance, but it has little influence in waist depth and waist width. Also, the microhardness of the weld seam doesn’t change a lot. In the condition of different laser power, welding speed, defocusing distances and overlap rate, it can obtain good-quality welding composite layer. The abrasion loss is closely relatedly to the surface hardness. The greater the hardness value, the smaller the amount of abrasion loss. At the laser power of 400 W, welding speed of 0.8 m/min, defocusing of 0 mm and overlap rate of 60, it respectively gets their minimum value. By analyzing the wear morphology, it is mainly adhesive wear. The corrosion perance was tested and compared with the 304 stainless steel base material, The corrosion resistance of the compound layer is slightly worse than that of that of 304 stainless steel . The surface hardness of Inconel 718 alloy and 27SiMn steel was 1.74 times higher than that of the 304 stainless steel and 27SiMn steel welded compound layer, and the wear perance was better than that of the 304 stainless steel and 27SiMn steel welded compound layer. Corrosion resistance was slightly worse than that of 304 stainless steel and 27SiMn steel welding compound layer. There are 37 figures, 18 tables and 91 references in this paper. Keywords laser welding; 304 stainless steel; Inconel 718 steel; welding compound layer; wear resistance; corrosion resistance 万方数据 IV 目 录 摘摘 要要 ........................................................................................................................... I 目目 录录 ......................................................................................................................... IV 图清单图清单 ..................................................................................................................... VIII 表清单表清单 ....................................................................................................................... XII 变量注释表变量注释表 ............................................................................................................. XIII 1 绪论绪论 ............................................................................................................................ 1 1.1 选题背景及意义...................................................................................................... 1 1.2 激光焊接技术.......................................................................................................... 2 1.3 液压支架立柱修复技术.......................................................................................... 4 1.4 异种金属激光焊接研究现状................................................................................. 9 1.5 本文研究内容....................................................................................................... 12 2 试验材料、设备及方法试验材料、设备及方法 .......................................................................................... 13 2.1 试验材料................................................................................................................ 13 2.2 试验设备................................................................................................................ 14 2.3 试验方法................................................................................................................ 15 2.4 本章小结............................................................................................................... 20 3 304 不锈钢不锈钢/27SiMn 钢焊接性及显微组织分析钢焊接性及显微组织分析 .................................................... 21 3.1 304 不锈钢焊接接头组织凝固模式分析............................................................. 21 3.2 27SiMn 钢激光焊接接头组织凝固模式分析 ...................................................... 24 3.3 304 不锈钢/27SiMn 钢光纤激光焊焊焊缝组织.................................................. 27 3.4 304 不锈钢/27SiMn 钢激光焊接接头显微硬度分析.......................................... 29 3.5 本章小结............................................................................................................... 30 4 工艺参数对焊缝形貌及力学性能影响工艺参数对焊缝形貌及力学性能影响 .................................................................. 31 4.1 激光功率对焊缝形貌及硬度影响........................................................................ 31 4.2 焊接速度对焊缝形貌及力学性能影响................................................................ 35 4.3 离焦量对焊缝形貌及力学性能影响.................................................................... 39 4.4 本章小结............................................................................................................... 42 5 激光包覆焊制备激光包覆焊制备 304 不锈钢不锈钢/27SiMn 钢复合层钢复合层 .................................................. 44 万方数据 V 5.1 工艺参数对复合层的影响.................................................................................... 44 5.2 工艺参数对复合层硬度的影响............................................................................ 48 5.3 工艺参数变化对复合层耐磨性的影响................................................................ 51 5.4 304 不锈钢/27SiMn 钢复合层的耐腐蚀性分析.................................................. 53 5.5 本章小结............................................................................................................... 55 6 激光包覆焊制备激光包覆焊制备 Inconel 718 合金合金/27SiMn 钢复合层钢复合层 ........................................ 57 6.1 Inconel 718 合金/27SiMn 钢复合层组织分析 .................................................... 57 6.2 Inconel 718 合金/27SiMn 钢复合层表面硬度及磨损性能分析 ........................ 58 6.3 Inconel 718 合金/27SiMn 钢复合层的耐腐蚀性分析 ........................................ 59 6.4 本章小结............................................................................................................... 60 7 总结与展望总结与展望 ............................................................................................................. 60 7.1 总结....................................................................................................................... 62 7.2 展望....................................................................................................................... 63 参考文献参考文献 ..................................................................................................................... 64 作者简历作者简历 ..................................................................................................................... 69 学位论文原创性声明学位论文原创性声明 ................................................................................................. 70 学位论文数据集学位论文数据集 ......................................................................................................... 71 万方数据 VI Contents Abstract ...................................................................................................................... III Contents ...................................................................................................................... VI List of Figures ......................................................................................................... VIII List of Tables ............................................................................................................. XII List of Variables...................................................................................................... XIII 1 Introduction ............................................................................................................... 1 1.1 Research Background and Significance ................................................................... 1 1.2 Technology of Laser Welding .................................................................................. 2 1.3 Repair Technology of Hydraulic Support Column .................................................. 4 1.4 Research Situation of Laser Welding for Different Steel ......................................... 9 1.5 Main Work and Technical Road ............................................................................. 12 2 Experimental Materials，，Equipments and s .......................................... 13 2.1 Experimental Materials .......................................................................................... 13 2.2 Experimental Equipments ...................................................................................... 14 2.3 Experimental s ........................................................................................... 15 2.4 Chapter Summary .................................................................................................. 20 3 Weldability and Microstructure Analysis of 304 Stainless Steel and 27SiMn Steel ...................................................................................................................................... 21 3.1 Analysis of Microstructure Solidification Model of Welded Joints for 304 Stainless Steel in Laser Welding ................................................................................................. 21 3.2 Analysis of Microstructure Solidification Model of Welded Joints for 27SiMn Steel in Laser Welding .......................................................................................................... 24 3.3 Microstructure of 304 Stainless Steel and 27SiMn Steel in Fiber Laser Welding . 27 3.4 Microhardness of Welded Joints for 304 Stainless Steel and27SiMn Steel in Laser Welding .................................................................................................