[航空航天]X80钢论文：X80钢激光-MAG复合焊接接头组织性能研究.doc

X80钢论文：X80钢激光-MAG复合焊接接头组织性能研究【中文摘要】本课题是针对中厚X80高强钢板对接焊接的需求,为了全面掌握激光-电弧复合焊接厚板的焊接技术和焊接性能,以光纤激光和MAG电弧为热源,开展坡口钝边为6mm的高强钢厚板激光-电弧复合焊接技术的基础研究,实现高强钢平板对接的平焊、45爬坡焊、立焊、斜仰焊和仰焊位置焊缝根焊一次焊接完成,并对这五个工位的焊接接头的组织和性能进行研究。通过对五个工位的激光-MAG焊接试验研究,得出了各个工位的最优焊接参数。其中平焊的最优焊接参数为：激光功率3500W,离焦量0,送气速度30l/min,保护气使用的是18%CO2,82%Ar混合气体,光丝间距5mm,两个板之间的间隙采取0.6mm,电弧的平均电流为220A。其他几个工位焊接最优参数相同：激光功率3800W,离焦量0,送气速度30l/min,保护气使用的是18%CO2,82%Ar混合气体,光丝间距0,两个板之间的间隙采取0.6mm,电弧的平均电流为220A。分别选取五个工位的焊接接头,对其中的热影响区组织和焊缝组织进行比较研究,得出工位对组织影响不大,各个工位的热影响区中组织类型基本一致,均主要由各种铁素体构成,焊缝组织主要由针状铁素体构成。此外还对五个工位的焊接接头性能进行了研究,对五种接头分别进行了拉伸测试、夏比冲击测试和硬度测试,综合各中种测试的结果,得出平焊工位的综合力学性能最好。【英文摘要】With the extensive application of X80 steel, it has great significance to carry out high-strength steel plate butt welding test. In order to comprehensively grasp the thick plate of laser-arc hybrid welding technology and performance, this paper make the topics of X80 high-strength steel plate laser-arc hybrid welding technology for basic research. Hybrid welding using optical fiber laser and MAG arc as heat source to achieve a complete high-strength steel plate butt weld root of Welding. The welded joints open V-groove, blunt the edge thickness of 6mm. There are five welding station, flat position welding, inclined welding, vertical position welding, inclined-overhead welding and overhead welding. The microstructure and mechanical properties of this five welded joints have also been studied.Through the five-station laser-MAG welding experimental research, each station obtained the optimal welding parameters. The optimal parameters of flat welding is described as below:the power of laser is 3500W; the defocusing amount is 0; the speed of the shielding gas is 301/min; the shielding gas composition by 18%CO2 and 82%Ar; the distance between laser and wire is 5mm; the gap between the two plate is 0.6mm and the arc average current is 220A. The other several welding stations have the same optimal parameters. It is described as below:the power of laser is 3800W; the defocusing amount is 0; the speed of the shielding gas is 301/min; the shielding gas composition by 18%CO2 and 82%Ar; the distance between laser and wire is 0; the gap between the two plates is 0.6mm and the arc average current is 220A.The microstructure of the heat-affected zone and the weld in five welding bead station has also been studied. As can be seen from the results, welding station has little impact on the microstructure. The types of microstructure of the heat-affected zone in each welding station are basically the same, mainly constituted by a variety of ferrite. The microstructure of welding bead is mainly constituted by acicular ferrite. In addition, five welding stations on the mechanical properties of welded joints have been studied. The five kinds of joints were carried out tensile test, Charpy impact testing and hardness testing. Summing up all the kinds of test results, concluded that the mechanical properties of the flat position welding is best.【关键词】X80钢 激光-MAG复合焊接 焊接工位 针状铁素体【英文关键词】X80 Line-pipe Steels Laser-GMA Hybrid Welding Welding Station Acicular Ferrite【目录】X80钢激光-MAG复合焊接接头组织性能研究摘要4-5ABSTRACT5目录6-8第一章 绪论8-241.1 前言8-91.2 激光复合焊接的基础知识概述9-171.3 X80管线钢的应用现状17-211.4 本课题研究的主要内容21-221.5 课题研究方法及思路22-24第二章 X80钢光纤激光复合焊接工艺实验24-332.1 前言242.2 实验材料24-252.3 光纤激光-MAG电弧复合焊接试验系统的组建25-272.4 X80钢光纤激光-MAG复合焊接工艺实验方法27-322.5 本章结论32-33第三章 X80钢复合焊接接头的金相组织分析33-523.1 前言333.2 焊接接头母材组织特征及针状铁素体介绍33-343.3 焊接接头宏观组织分析34-403.4 焊接接头微观组织分析40-513.5 本章小结51-52第四章 X80钢复合焊接接头的力学性能研究52-634.1 前言