药芯焊丝的加热数学模型与加热动力学

建立了药芯焊丝伸出长度上的加热数学模型，对不同焊接工艺参数下药芯焊丝伸出长度上的温度进行了测量和理论计算。对于直径为φ１．２ｍｍ的细直径药芯焊丝，电阻热使药芯焊丝的伸出长度被加热，电弧热的主要作用是使焊丝熔化和熔滴过热，药芯粉的分流作用和电弧热对药芯焊丝的加热灵堂模型的影响很小，故药芯粉的分流作用、电弧热可以忽略不计。用差热、热重法分析了药芯焊丝伸出长度的加热动力学，在加热阶段，电阻热主要使氟化物

Heating Mathematical Model and Thermal Dynamics of Flux Cored Wire

The heating mathematical model of flux cored wire extension was founded.The temperature distribution rule of flux cored wire extension was measured and calculated when welding parameters were different.The resistance heat made flux cored wire extension heated and the arc heat made flux cored wire melted and the droplet overheated.The influence of shunting current of the flux powder in flux cored wire and arc heat on the heating mathematical model of flux cored wire extension was little and could be ignored when the diameter of flux cored wire is 1.2mm.The thermal dynamics of flux cored wire was analysed with thermogravimetry analysis(TGA)and differential thermal analysis(DTA).The resistant heat caused the decomposition of fluoride compounds,the loss weight of flux cored wire,the oxidization of the Fe-alloy and increment weight of flux cored wire during heating process.The oxidization of the Fe-alloy caused that the transfer efficiency of alloy element became lower and influenced the chemical composition and mechanical properties of weld metal.