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实验中使用1.3mm厚DP780双相钢和1mm厚的5083铝合金板材的尺寸均为180mm×100mm,主要化学成分如表 1所示。搭建图 1所示的焊接系统。采用Trumpf 10002碟片激光器,激光束通过光纤进行柔性传输,传输光纤最小直径为200μm。采用最大功率10kW的连续激光器,输出波长1030nm,额定功率下的功率输出稳定性为±1%。
Table 1. Main chemical composition of substrate material (mass fraction)
material Mn Si Ti Mg C P S Zn Cr Al Fe DP780 0.0195 0.00235 — — 0.0016 0.00022 0.00007 — — 0.00132 balance 5083 0.005 0.001 0.0003 0.047 — — — 0.0003 0.001 balance 0.003 -
实验中采用钢上铝下的搭接方法,示意图如图 2所示。搭接距离为35mm,用氮气保护,氮气的流速是15L/min。
影响焊接结果的主要因素有:激光功率、焊接速率和离焦量,其中激光功率对焊缝的影响最为显著。因此本文中主要研究激光功率对焊缝宏观形貌、微观组织、显微硬度和焊缝拉伸性能的影响。根据以往的焊接经验,激光功率在1400W~1600W之间焊缝成型效果较好[14],为获得良好的焊接效果焊接功率的窗口范围,设计如表 2所示的实验参数。
Table 2. Welding parameters
serial No. laser power/W wobble breadth/mm wobble cycle/mm wobble frequency/Hz welding speed/ (mm·s-1) 1# 1300 1 0.786 28 22 2# 1400 1 0.786 28 22 3# 1500 1 0.786 28 22 4# 1600 1 0.786 28 22 5# 1700 1 0.786 28 22 使用钢刷打磨钢铝材料,使用工业乙醇进行清洗,除去表面多余油脂和杂质。沿着焊缝垂直方向切割拉伸和金相试样。切割后的金相试样使用800#、1500#、2000#的砂纸依次打磨表面,然后使用金相磨抛机(UniMP-202)对试样进行机械抛光以得到光泽镜面。使用V(HF): V(HNO3): V(H2O)=1:2:7的溶液对试样表面进行腐蚀,使用平面测量显微镜(VH1202)和数字化金相显微镜(Ario Image.M2m)对焊缝形貌和微观组织进行分析。使用显微维氏硬度计(Buehler VH1202)测量焊缝的显微硬度,测量标准选用ASTM E384,测量时加载力为500g,保压时间为10s。拉伸试验使用电子万能拉伸试验机(上海捷沪CMT4202),拉伸试样规格为20mm×130mm,实验时,分别在两侧的母材处加入1.2mm和1mm厚度的垫板,保证拉伸力与接头界面平行。
不同功率对激光摆动焊接钢/铝异种材料的影响
Influence of different power on laser swing welding of steel/aluminum dissimilar materials
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摘要: 为了得到高质量的钢/铝接头, 采用激光摆动焊接的方法、使用不同的功率对DP780双相钢和5083铝合金两种金属进行了搭接实验, 研究了不同焊接功率对钢/铝接头宏观形貌、微观组织和力学性能的影响。结果表明, 1400W~1600W的功率区间内可有效实现板材焊接; 激光功率为1400W和1500W时, 焊接接头的金相组织以马氏体为主, 当激光功率为1600W时, 接头内的铁素体增多, 马氏体减少, 焊接接头的金相组织以铁素体为主; 3种接头显微硬度的最低值和最高值分别位于焊缝中心和热影响区, 在1500W的激光功率下, 焊接接头的力学性能最好, 钢侧接头的显微硬度约高于母材显微硬度的1.7倍; 接头的最大剪切强度达到113N/mm。此研究结果应用在船舶制造领域具有较重要的意义。Abstract: In order to obtain high quality steel/aluminum joints, the lapping experiments of DP780 duplex steel and 5083 aluminum alloy with different power were carried out by laser swing welding. The effects of different welding power on the macroscopic morphology, microstructure, and mechanical properties of steel/aluminum joints were investigated. The test results show that the plate welding can be effectively realized within the power range of 1400W~1600W. When the laser power is 1400W and 1500W, the metallographic structure of the welded joint is dominated by martensite. When the laser power is 1600W, the amount of ferrite in the joint increases, while the martensite decreases, and the metallographic structure of the welded joint is dominated by ferrite. The lowest and highest microhardness of the three joints were located in the weld zone and the heat affected zone, respectively. Under the laser power of 1500W, the mechanical properties of the welded joint are the best, and the microhardness of the steel side joint is about 1.7 times higher than that of the base metal. The maximum shear strength of the joint is 113N/mm. The research results are of great significance in the field of shipbuilding.
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Key words:
- laser technique /
- laser swing welding /
- laser power /
- metallographic structure /
- microhardness /
- shear strength
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Table 1. Main chemical composition of substrate material (mass fraction)
material Mn Si Ti Mg C P S Zn Cr Al Fe DP780 0.0195 0.00235 — — 0.0016 0.00022 0.00007 — — 0.00132 balance 5083 0.005 0.001 0.0003 0.047 — — — 0.0003 0.001 balance 0.003 Table 2. Welding parameters
serial No. laser power/W wobble breadth/mm wobble cycle/mm wobble frequency/Hz welding speed/ (mm·s-1) 1# 1300 1 0.786 28 22 2# 1400 1 0.786 28 22 3# 1500 1 0.786 28 22 4# 1600 1 0.786 28 22 5# 1700 1 0.786 28 22 -
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