Experimental Studies of Defect Formation during Pipe Reducing

This article describes experimental studies of reducing during one pass rolling of pipes from ShKh-15 steel at laboratory rolling mill. Designing and processing of experimental data have been performed by means of complete factorial experiment. According to the results, the changes in the wall thickness depend on partial deformation of external diameter. The wall thickening increases with partial deformation. Analysis has demonstrated that the curvature of the end area decrease with decrease in temperature, the degree of wall thinness of workpieces, and the partial deformation in reducing mill stands. The temperature has exposed the minimum influence of the mentioned parameters. As a consequence of the work, the experimental dependence has been developed describing the influence of the deformation extent on the changes in wall thickness, the critical degree of partial deformation has been specified. It has been concluded that the wall thickening and probability of defect occurrence can be reduced due to decrease in the workpiece diameter before the reducing mill.