Abstract
It is of great significance to investigate the welding temperature field of pipeline around weld joint during welding process for analyzing the thermal stress and evaluating the performance and service life of welded pipelines. In this work, a pipeline butt welding experiment of P280GH steel was conducted to figure out the evolution of welding temperature field and parameters that affected welding temperature field. 27 effective measuring points were placed at different positions along external and internal surfaces in 3 directions (3, 9, and 12 o’clock directions on the circumference of the cross section). By using the thermocouple temperature measurement method, the welding temperatures for all 37 cycles of the argon arc welding process were monitored and recorded. The results indicate that the most critical parameter of temperature field was the distance from the welding position to measuring point. The temperature rose significantly and then dropped as the welding torch passed by a measuring point. The temperature of the measuring point changed more dramatically as it was closer to the weld joint. With the increase in the number of welding cycles resulting in the superposition of weld metal, the magnitude of temperature evolution at the measuring points on the external surface increased progressively, whereas that on the internal surface decreased gradually.
