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实验中使用的材料为1.3mm×100mm×100mm的DP780双相钢和1mm×100mm×100mm的5083铝合金,其主要化学成分如表 1所示。焊接系统如图 1所示。采用Trumpf 10002碟片激光器和PFO3D摆动接头,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,光束质量为8nm·mrad,额定功率下的功率输出稳定性稳定在±1%。
表 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,其示意图如图 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[15]。因此作者旨在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。为获得良好的焊接效果、焊接功率的窗口范围,设计如表 2所示的实验参量。
Table 2. Welding parameters
serialNo. laserpower/W wobblebreadth/mm wobblecycle/mm wobblefrequency/Hz weldingspeed/(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 焊接前使用钢束打磨材料表面,并用100%的工业乙醇进行清洗,去除表面杂质和多余油脂。焊接结束后,沿焊缝垂直方向切割金相试样和拉伸试样。依次使用400#、600#、1000#、1500#、2000#的砂纸对试样表面打磨抛光,随后使用wHF∶wHNO3∶wH2O=1∶2∶7的溶液对试样表面进行腐蚀,通过平面测量显微镜和金相显微镜对焊缝的宏观与微观进行观察,使用维氏硬度计对不同焊缝的硬度进行测量,加载力为500g,加载时间为10s。采用电子样拉伸机测量焊缝最大拉伸力,拉伸试样是180mm×20mm的长条状试样,拉伸速率为2mm/min。
激光摆动焊接的功率对钢/铝焊接接头的影响
Influence of laser swing welding power on steel/aluminum welded joints
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摘要: 为了研究不同激光功率对摆动焊接钢/铝材料的影响,采用大功率碟片激光器和PFO3D摆动接头相结合,对DP780双相钢和5083铝合金两种金属进行了搭接实验。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时,焊接接头的金相组织为低碳马氏体,显微硬度的最低值和最高值分别位于热影响区和焊缝中心;随着激光功率的增加,焊缝内的铁素体增多,马氏体减少,接头显微硬度的最高值和最低值分别改为热影响区和焊缝中心;当激光功率为1400W时, 焊缝抗拉强度最高为2681MPa。此研究结果在船舶制造的领域应用具有较为重要的意义。Abstract: In order to study the influence of different laser power on swing welding steel/aluminum, the lap experiments of DP780 dual-phase steel and 5083 aluminum alloy were carried out by combining a high-power disc laser with a swing joint of PFO3D. The experimental results show that the plate welding can be effectively realized within the power range of 1400W~1600W. When the laser power is 1400W, the microstructure of the welded joint is low carbon martensite, and the lowest and highest microhardness are located in the heat affected zone and the weld center, respectively. With the increase of laser power, the amount of ferrite in the weld increases, while the amount of martensite decreases. The maximum and minimum values of microhardness of the joint are changed to heat affected zone and weld center, respectively. When the laser power is 1400W, the tensile strength of the weld is the highest, which is 2681MPa. 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 /
- mechanical properties
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Figure 5. Metallographic structure of 2# welded joint
a—overall morphology of the weld b—top of the steel side of the weld c—fusion line between the weld and heat-affected zone d—heat affected zone at the bottom of the weld e—end of the aluminum side of the weld f—fusion line between the heat-affected zone of the weld and the base metal
Figure 6. Metallographic structure of 3# welded joint
a—overall morphology of the weld b—top of the steel side of the weld c—fusion line between the weld and the heat affected zone d—end of the aluminum side of the weld e—heat affected zone at the bottom of the weld f—fusion line between the heat affected zone of the weld and the base metal
Figure 7. Metallographic structure of 4# welded joint
a—overall morphology of the weld b—top of the steel side of the weld c—fusion line between the weld and the heat affected zone d—end of the aluminum side of the weld e—heat affected zone at the bottom of the weld f—fusion line between the heat affected zone of the weld and the base metal
表 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
serialNo. laserpower/W wobblebreadth/mm wobblecycle/mm wobblefrequency/Hz weldingspeed/(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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