热丝TIG焊热丝准稳态温度场的解析模型

Mathematical Model of Quasi-state Temperature Distribution of Hot-Wire during Hot-Wire TIG Welding Process

基于能量守恒和傅里叶定律,建立了电阻加热和熔池传热对热丝温度分布影响的数学模型;基于叠加原理建立了电阻加热热丝钨极惰性气体(TIG)焊热丝准稳态温度分布的数学解析模型,并验证了其计算结果;讨论了热丝电流密度、送丝速度以及焊丝干伸长等因素对焊丝温度分布的影响规律.结果表明:该数学模型具有很高的精确性,可用于热丝加热过程的分析.焊丝电流密度越大,焊丝各位置温度越高;送丝速度越大,焊丝各点的温度越低;焊丝干伸长越大,焊丝端部的预热温度越高.得到了一定条件下焊丝电流密度、送丝速度和焊丝干伸长三者之间的数值匹配关系.

Based on the law of the conservation of energy and Fouriers law, the mathematical models re-spectively considering the effect of resistance heat and the heat transferred through the weld pool on the hot-wire temperature distribution were developed. And then based on the superposition principle the math- ematical model of quasi-state temperature distribution of ,hot-wire heated by resistance energy was devel- oped. The accuracy of the mathematical model was validated by comparing the result of calculating from the mathematical model with the experimental result from the literature. The impact of current density, wire feeding speed, wire extension on temperature distribution of hot-wire was elaborately discussed. The results show that the mathematical model has high accuracy to effectively analyze the process of wire heat-ed by resistance energy. The larger the current density or wire extension is, the higher the temperature in different positions on the wire extension is, however, the bigger the wire feeding speed is, the higher the pre-heating temperature is. In some certain cases, the matching relations among current density, wire feeding speed and wire extension can be concluded.