50CrV钢激光填丝焊焊缝成形多元非线性回归模型

Multivariate Nonlinear Regression Analysis Model of Weld Bead Shaping of 50CrV Steel by Laser Welding with Filler Wire

在焊接50CrV薄板时,焊缝熔深要求控制在2 mm.为获得特定要求的熔深,基于响应面设计方法,采用实验设计软件Design-Expert 8. 0对50CrV钢激光填丝焊焊接工艺进行了实验设计。实验过程中,以特定的焊缝熔深(2 mm)、最小化熔宽及余高为响应;以激光功率、焊接速度、送丝速度与离焦量作为控制变量,测量描述焊缝特征的响应数据,并建立其与焊接参数之间相关性的数学模型,通过方差检验确定了所建立的数学模型准确性。模型分析结果表明:激光功率、焊接速度、送丝速度与离焦量4个主因素对焊缝成形有直接的影响;根据优化结果得到最佳焊接条件,激光功率3. 17～3. 33 kW,焊接速度1. 30～1. 40 m/min,送丝速度4. 0～4. 23 m/min,离焦量3. 1～4. 5 mm,此时可获得满足焊接要求的熔深、熔宽和余高;实验验证了预测结果与实际焊接结果相一致,可用于指导实际生产。

The weld penetration should be precisely controlled at 2 mm when welding 50CrV steel plates. The response surface design method is used to meet the requirement. The experimental design of laser filler wire welding process for 50CrV steel is made by using Design-Expert 8.0 software. During the experiment, the laser power, welding speed, wire feeding speed and defocusing distance are presumed as the welding process parameters, and the specific weld penetration （2 mm） , minimized weld width and weld reinforcement are considered as the process responses. Weld bead measurements are carried out to generate the response dataset of describing weld characteristics, and the mathematical models correlating the process parameters with the responses are developed. The accuracy of the established mathematical model is determined by variance test. The result shows that the laser power, welding speed, wire feeding speed and defocusing distance have significant inffluence on the weld bead geometry. According to the optimizated results, the laser power of 3.17 - 3.33 kW, welding speed of 1.30 - 1.40 m/min, wire feeding speed of 4.0 - 4.23 m/min, and defocusing distance of 3.1 - 4.5 mm are identified as the optimal process parameters. Under these process conditions, the weld penetration, weld width and weld reinforcement meet the welding requirement. The verification experiment shows that the predicted results are consistent with the actual welding results.