论文部分内容阅读
利用脉冲固体激光器对厚度1mm车用冷轧退火态双相钢DP590进行了激光焊接实验,研究了脉冲激光功率(45~130 W)对焊接接头的宏观形貌(横截面形貌、熔深、熔宽)、微观组织、力学性能及成形性能的影响,同时分析了冲压成形方向对焊接接头成形性能的影响。结果表明,随着脉冲功率的提高,焊缝区凹陷量、焊缝熔深及熔宽均逐渐增大,脉冲功率为75W及以上可获得全熔透焊缝,焊缝横截面形貌变化规律为“Y”型→“V”型→“X”型;不同的脉冲功率条件下,焊缝区组织以板条马氏体为主,但随脉冲功率的增加,焊缝中逐渐出现贝氏体和铁素体,导致焊缝区硬度逐渐降低;对于全熔透焊缝而言,拉伸实验失效位置均出现在母材区,断裂方式为韧性断裂。“Y”型焊接接头成形性能最差,且对冲压方向最为敏感,“V”型焊接接头成形性能居中,“X”型焊接接头成形性能最佳,脉冲功率为90~100 W时,焊接接头的杯突值可达到母材的80%左右。
The pulse laser was used to laser-anneal the as-annealed dual phase steel DP590 with a thickness of 1mm. The effects of pulsed laser power (45 ~ 130 W) on the macro morphology of the welded joint (cross section morphology, penetration depth, Melting width), microstructure, mechanical properties and formability. The influence of forming direction on the formability of welded joints was also analyzed. The results show that with the increase of pulse power, the amount of depression in the weld zone, the penetration depth and the melting width of the weld seam all increase gradually. The variation of the cross-sectional morphology of the full penetration weld and the weld seam can be obtained when the pulse power is 75W and above For the “Y” type → “V” type → “X” type, under the different pulse power conditions, the weld zone was dominated by lath martensite, but with the increase of pulse power, The bainite and ferrite gradually appear in the seam, which leads to the gradual decrease of the hardness of the weld zone. For the fully welded weld, the failure test of the tensile test occurs in the base metal zone and the fracture mode is ductile fracture. “Y ” welded joint has the worst formability and the most sensitive to the stamping direction, “V ” welded joint has the best formability, “X ” welded joint has the best formability and the pulse power is 90 ~ 100 W, the solder joint cup protruding value can reach about 80% of the base metal.