Abstract: Briefed are the characteristics and advantages of three types of hot expanding processes.The influence of the intermediate frequency induction heating and plug pushing hot expanding process on the expanded pipe is analyzed, and notable problems are pointed out.The analysis leads to the following conclusions.A blank is not simultaneously heated on its entire length in an intermediate frequency induction heating and plug pushing hot expanding process, but, comparing to the overall heating and hot expanding process, this heating method has no obvious influence on pipe deformation.The quality of blanks as well as blank temperatures at deforming areas shall be well controlled.Reasonable deforming parameters shall be chosen.Pipes after expanding shall receive overall heat treatment.Quality inspection on finished pipes shall be enhanced.