随着四化建设、工业技术不断向前发展,在石油、化工、电力等工业部门,高温高压设备、容器越来越多,如加氢裂化的反应塔及系统管线、高压锅炉等等,它们在制造过程中,一般要求焊前预热,焊后去氢、退火等处理,以改善焊接接头区的机械性能,消除焊接残余应力。 With the four modernizations, industrial technology continues to develop. In the petroleum, chemical, power and other industrial sectors, there are more and more high-temperature and high-pressure equipment and vessels, such as hydrocracking reaction towers and system lines, high pressure boilers, etc. In the manufacturing process, generally require preheating before welding, after welding hydrogen, annealing and other treatment to improve the mechanical properties of the welded joint area, to eliminate welding residual stress.