The heat transfer models established in the paper have important reference value to establishing the complex models that consider comprehensively heat transfer, mass transfer and flow.

In the thermal analysis, the initial temperature of billet, beat fluxes (heat flow per unit area) of positive and negative value and convections to surrounding air are considered.

Calculation showed that when the heat flow is in steady state, temperature-increasing difference in inner, outer pipe walls bearable for partial corrosive pipeline represents a minimum value.