Study and application on low velocity and great pressure friction couple for large diameter petroleum steel pipe

This paper analyzes the reasons of frictional abrasion and proposes that lowing the friction couple is crucial to the mechanical expanding methods of large diameter longitudinal pipe which is used for transportation of oil and gas. Research on the lubricate status on the wedge interface shows that the friction interface is in the boundary and mixed situation. This paper makes researches on the reducing the frictional coefficient on the frictional interface, the high viscosity and good extreme pressure lubricating oil in accordance with working on the condition of low velocity and high pressure. The low friction coefficient mechanical expanding equipment is manufactured by combining the manufacture of the high intensity, high abrasive resistance and good oil absorption friction couple and reasonable heat treatment process and process on the surface of large die block. This equipment is used in the practical producing, and the effect is good.