Abstract: With the continuous development of petrochemical industry, the demand for titanium heat exchanger is increasing year by year in China. Unlike other material heat exchangers, titanium heat exchangers have strict requirements of gas protection when welding heat exchanger tubes and pipe plate joints.Inert gas protection should be applied to molten pools and welds and heat affected zones at temperatures over 400 ℃. In actual production, this intended purpose was achieved by adding a protective gas nozzle to the tungsten electrodes and adding a gas shield for the tube plates. In the whole welding process, gas shield of tube sheet needs to be moved the tube plate gas protection cover constantly based on the welding position.The process is cumbersome and the production efficiency is low.In this paper, Having used ANSYS Workbench numerical simulation software to simulate the temperature field of joint’s welding process and improving the traditional gas protection measures based on the distribution of temperature field.After the actual welding test,This improved gas protective measure worked well and could be applied to actual production.

Key words: Titanium, Gas protection, Numerical simulation, Optimization

摘要： 随着石油化工行业的不断发展，我国对钛制换热器的需求量逐年增加。与其他材质换热器不同，钛换热器在焊接换热管与管板接头时，有严格的气体保护要求，对熔池及温度超过400 ℃的焊缝和热影响区都要进行惰性气体保护。在实际生产中，一般通过给钨极加装保护气体喷嘴以及增加管板气体保护罩的形式实现。在整个管板焊接过程中，需要根据焊接位置不断移动管板气体保护罩，过程冗杂，生产效率低。利用ANSYS Workbench数值模拟软件，模拟钛管头焊接过程的温度场，以温度场分布为依据，优化传统气体保护措施。通过实际焊接检验可知，改进后的气体保护措施效果良好，可以应用于实际生产。

关键词: 钛, 气体保护, 数值模拟, 优化