AN EFFECTIVE MEASURE TAKEN TO UNIFORM WALL THICKNESS OF LARGE DIAMETER AND LIGHT WALL PIPES ON φ140 MILL

The distribuution of non-uniform wall thinkness in cross-section of large diameter and thin wall pipes produced on φ140 plug mill is described. In the production of large diameter and thin wall pipes, non-uniform wall thickness distributed in spirality can be improved and the products whose wall thickenss is out of tolerance range and needs grinding can be decreased by properly increasing the wall thickness reduction amount in the first pass.