TA0Q235异种金属的等离子焊接工艺研究

魏氏体组织和珠光体组织。铜与钢的结合界面出现平面结晶带，钛铜结合界面边界附近区域颗粒的尺寸偏小，但密度较大，外部的颗粒尺寸较大且分布稀疏通过对模拟温度场发现，等离子焊过程中温度上升、下降的速度非常快。当钛与钢直接对焊时，焊缝温度高达2200°C,而当有铜做中间层时，温度下降到1700°C。温度梯度明显减小。对应立场进行模拟发现，焊缝两侧不同金属的应力场分布不均匀。TA0与Q235直接焊接时，应力最大值高达433MPa,而添加中间层后下降到404MPa,残余应力也由606MPa下降到474MPa。并且添加中间层后，试件的应力分布较直接焊更为均匀，应力梯度也更小。关键词：TA0:Q235低碳钢：等离子焊接：数值模拟AbstractIn this subject,TAO and Q235 low-carbon steels are subjected to internal plasma weldingexperiments.The cladding method is used to analyze the weldability of TA0 and Q235 steelsunder different conditions with and without an intermediate layer.Cu is used as anintermediate layer.In the case of welding,the effect of welding current and welding speed onthe microstructure and mechanical properties of the joint,and using ABAQUS finite elementsimulation software for two different cases of direct butt welding of TA0 and Q235 plates andthe addition of copper in the middle layer,the temperature field and stress fields wasperformed Numerical simulation.research shows:When TA0 powder directly cladding on the Q235 substrate,the two could not be reliablyconnected,obvious cracks appeared on the weld surface,and the cladding layer even felloff.Therefore,copper is used as the intermediate layer,and the best welding processparameters are studied on the basis of copper as the intermediate layer.When the plasmawelding current is between 90A-100A,the weld surface is well formed without defects.When the welding current is between 95A-105A,the microstructure is well bonded withoutobvious defects.With the increase of welding current,the width of the weld seam increases,the dendrite structure becomes thicker,and the grain size increases.When the welding currentis 100A,the maximum hardness of 448HV is reached.The maximum tensile strength can川