为研究Q235/316异种薄钢板激光焊接的最优工艺参数, 采用Nd: YAG脉冲激光器对其进行激光拼焊试验。设计五因素四水平的正交试验, 研究各工艺参数对断后伸长率、抗拉强度的影响, 通过极差分析法优化焊接参数, 并用多目标模糊综合评价法寻找出综合最优参数组合。结果表明, 工艺参数对断后伸长率和抗拉强度的影响因素大小均为离焦量＞脉宽＞频率＞扫描速度＞电流, 离焦量D是焊接质量最主要的影响因素; 断后伸长率对应的最优组合是A4B4C4D4E1, 抗拉强度对应的最优组合是A1B4C3D4E2, 经模糊综合评价后综合最优工艺参数是电流P为150 A、脉宽T为2.4 ms、频率f为22 Hz、离焦量h为-17 mm和扫描速度v为250 mm/min; 优化后试样焊接质量稳定、力学性能良好。

In order to study the optimal process parameters of laser welding of Q235/316 dissimilar thin steel plate, the laser tailor welding test was carried out by Nd: YAG pulsed laser. Five factors and four levels of orthogonal experiments were designed to study the effects of various process parameters on elongation and tensile strength after fracture. The welding parameters were optimized by range analysis method, and the comprehensive optimal parameter combination was found by multi-objective fuzzy comprehensive evaluation method. The results show that the factors affecting the elongation and tensile strength of the process parameters are defocus amount>pulse width>frequency>scanning speed>current, and the defocusing amount D is the most important influencing factor of welding quality; The optimal combination of the rate is A4B4C4D4E1, and the optimal combination of tensile strength is A1B4C3D4E2. After the fuzzy comprehensive evaluation, the integrated optimal process parameters are current P of 150 A, pulse width T of 2.4 ms, frequency f of 22 Hz, defocusing. The quantity h is -17 mm and the scanning speed v is 250 mm/min; after optimization, the welding quality of the sample is stable and the mechanical properties are good.