光学学报, 2015, 35 (s1): s114008, 网络出版: 2015-07-27
高强钢激光热应力成形的试验研究
Experimental Study on Laser Thermal Stress Forming of High Strength Steel
摘要
利用CO2激光器对汽车用高强钢板作了大量的热应力成形试验,并对材料进行了相关的微观组织分析。在深入研究试件弯曲角变化规律的基础上,对激光热应力成形的工艺参数进行了合理优化,即在激光功率为1.5 kW、扫描次数为6次、扫描速度为1.2 m/min以及激光光斑直径为3.5 mm、面能量在20~45 J/mm2范围之间变化时热应力成形效果最好,提出了避免工件表面出现烧蚀现象的条件。试验结果表明,在试验参数的有效范围内激光扫描次数、扫描速度和材料宽度对试件弯曲角的影响趋于正比关系;光斑直径在较大或较小时呈现类线性关系;激光功率的影响呈明显的非线性特点,但在较小的情况下与弯曲角接近线性关系;接近材料表面区域的微观晶粒细小,而距离越远碳化物析出越少。
Abstract
Many laser thermal stress forming experiments of high strength steel plate used automobile are done by CO2 laser and the material relevant microstructures are analyzed. Based on the deep study of the changing law on the specimen bending angle, the process parameters are reasonably optimized about laser thermal stress forming. Namely the effect of thermal stress forming is the best when the laser power is 1.5 kW, scanning times are 6, the scanning speed is 1.5m/min and the diameter of laser spot is 3.5 mm and the surface energy changes between 20~45 J/mm2. The conditions are proposed to avoid the ablation phenomenon on the work piece surface. The test results show that the bending angle tends to the direct proportion relationship with laser scanning times, scanning velocity and material width in the effective range of the test parameters. That is a linear relationship when the spot diameter is the less or the more. The effect of the laser power is nonlinear obviously, but the bending angle tends to the direct proportion relationship with the laser power when the laser power is less. The microcosmic grain is smaller near the material surface and the carbide precipitation is less farther the surface.
伍强, 徐兰英, 杨永强, 孔春玉. 高强钢激光热应力成形的试验研究[J]. 光学学报, 2015, 35(s1): s114008. Wu Qiang, Xu Lanying, Yang Yongqiang, Kong Chunyu. Experimental Study on Laser Thermal Stress Forming of High Strength Steel[J]. Acta Optica Sinica, 2015, 35(s1): s114008.