目前,大型毛坯的焊前预热都是在炉中或在气体火焰中进行的。这种加热方法不仅使焊工的工作条件恶劣,更主要的是不能保证焊接质量。虽然局部电加热是较好的工艺方法,但也存在上述缺点。为了保证焊接坡口加热的均匀性和获得优质的焊接接头,本文采用了工频感应加热法。为了使焊根形成一个软的夹层,在每个毛 At present, the preheating of large blanks is carried out in a furnace or in a gas flame. This heating method not only makes the working conditions of welders harsh, but more importantly, it can not guarantee the welding quality. Although the local electric heating is a better process, but also the above shortcomings. In order to ensure the uniformity of welding groove heating and obtain high-quality welded joints, this paper uses the frequency induction heating method. In order for the root to form a soft interlayer, in each hair