细晶粒钛合金薄板TIG焊温度场分析

采用数值模拟和试验相结合的方法分析了不同晶粒尺寸的细晶粒Ti-6Al-4V钛合金薄板常规钨极氩弧焊(TIG)焊接过程中的温度场.结果表明,不同晶粒尺寸的细晶钛合金的温度场相似,但是随着母材晶粒尺寸减小,晶界增多,热导率与比热容都相应减小,且比热容减小幅度较大.所以较细晶粒尺寸钛合金热传递速度较慢,同一温度的等温线的范围大于较粗晶粒钛合金的相应值,并且距离焊缝中心越远,这种差距越明显.较细晶粒尺寸钛合金距离焊缝中心相同点的峰值温度也明显高于较粗晶粒尺寸钛合金.

Analysis of temperature field for TIG welding fine grain titanium alloy thin sheet

The temperature field for the conventional TIG welding of fine grain titanium alloy Ti-6Al-4V with different grain sizes is studied by numerical and experimental methods.The results show that the temperature field patterns and the temperature developing histories of fine grain Ti-6Al-4V alloy with different grain sizes are similar.But because of the refinement of base material grain size and the increment of grain boundaries,thermal conductivity and specific heat are both reduced,and the value of specific heat reduced is larger than that of thermal conductivity.So the heat conduction abilities of finer grain titanium alloy are weakened,the isothermal range of fine grained titanium alloys is larger than that of coarse grained titanium alloys,and the further the distances to central line of weld is,the more visible the difference is.The peak temperature of points with same distances to central line in fine grained titanium alloy is higher than that in coarse grained titanium alloy.