Discussion on Restrained Mandrel Service Life in a MPM Mandrel Mill

As for the common concern that is the restrained mandrel service life in a MPM mandrel mill a conception of the unit length elongation coefficient of a mandrel is put forward based on such parameters as the deformation distribution,mandrel working section length and mandrel service life when the products with same size are produced in deferent type mills,which means to reflect the mandrel loading in a quantification way and also to measure the restrained mandrel service life in deferent type mills with considering the pipe pieces rolled by a mandrel and the mandrel consumption per ton of rolled pipes. And the main failure mechanism,stress,strain and displacement of a mandrel during pipe rolling are analyzed and some factors which may impact the mandrel life are proposed for discussion.