酸性介质设备及管道焊缝热处理技术探讨

Heat Treatment Technology for Weld Lines of Equipment and Pipelines in Sour Gas Treatment Plant

酸性介质天然气设备及管道系统的焊缝存在残余应力,为了消除和降低其残余应力,减缓酸性介质对焊缝的腐蚀速度,需要对设备及管道系统的焊缝进行局部退火热处理。在天然气处理厂内对设备和管道系统焊缝的热处理一般采用电阻加热法。通过预设工艺参数的智能温控设备和温度传感仪控制输出的电流对电阻丝进行加热,利用热传导使工件按照要求的温度—时间曲线完成热处理过程。经过热处理后焊缝的硬度值和残余应力会大大降低,从而提高设备及管道的力学性能和耐应力腐蚀性能,延长其使用寿命。

Residual stress exists in welding lines of acidic media equipment and pipeline systems.In order to eliminate or reduce the residual stress,it is necessary to conduct local annealing heat treatment in welding lines of such equipment and pipeline systems to decelerate corrosion rate of acidic media on the weld lines.In natural gas treatment plant,generally used is resistance heating method for heat treatment in welding lines of equipment and pipeline systems.Used are intellective temperature control device and temperature sensor with preset technological parameters to control electric current output and heat up the electric resistance wire and utilized is heat conduction to complete the heat treatment process according to the specified temperature-time curve.Hardness and residual stress in welding lines will be reduced greatly after heat treatment process,accordingly,mechanical properties and stress corrosion resistance of equipment and pipeline systems will be improved and their service life will be prolonged.