基于质量流量控制保护气均匀混配的MAG焊改善研究

Research on the Improvement of MAG Welding Based on the Uniform Mixing of Protective Gas by Mass Flow Control

针对MAG焊(指熔化极活性气体保护焊)的保护气在现有钢瓶、传统现场混配的供气方式下,混合气体配比波动引起的焊接飞溅控制难题,提出一种基于质量流量控制的保护气均匀混配系统。该系统能在供气前端对不同流量的Ar与CO_(2)分别进行稳压控制,混配阶段采用毛细管传热温差量热法来精确控制保护气质量流量的混合配比,并在后端通过气体分析仪直接进行保护气的测量补偿与调节反馈,从而实现Ar+CO_(2)混合气体配比精度的稳定控制。现场应用验证表明,在设定混合气体配比为Ar∶CO_(2)=92∶8的情况下,该系统的CO_(2)混配比例误差≤0.34%,能有效避免混合气体配比波动带来的焊接飞溅问题。

A uniform and centralized mixing system based on mass flow control method is proposed to solve the problem of welding spatter control caused by the difference in mixed gas ratio under the existing gas supply methods of steel cylinders and manual mixing for MAG welding protective gas.The Ar and CO_(2)under different flow conditions are regulated and controlled by the gas supply front-end,and the mass flow mixing ratio is accurately controlled through capillary calorimetry during the mixing stage,Finally,agas analyzer is used in the backend to directly measure,compensate,and adjust the feedback,achieving stable and controllable accuracy of the Ar+CO_(2)mixture ratio,with a ratio accuracy of≤0.34%,when Ar∶CO_(2)=92∶8,effectively avoiding the welding spatter problem caused by the fluctuation of the mixture ratio.