METHOD OF ROLLING STRIPS FOR LARGER-DIAMETRE TUBES FROM LOWALLOY STEEL AT REVERSING THICK PLATE MILL Russian patent published in 2010 - IPC B21B1/22 

FIELD: process engineering.

SUBSTANCE: proposed method comprises heating, lengthwise roughing and crosswise rolling. Proposed invention aims at ruling out the formation of lateral laps after finish rolling. For this, lengthwise roughing of billet is performed to billet thickness making 8-16 thicknesses of finished strip while roughing is performed to thickness making 3-7 thicknesses of finished strip in at least 5 sequential reversing passes. Note that in at least two said passes lateral bevels are formed on the billet front surfaces along both lateral faces on the width of 10-25 thicknesses of finished strip. To this end, uniform regulated decrease in single absolute thickness reduction is performed on one edge of the billet, while, on the opposite edge, it is increased to produce intermediate billet. Said billet has lateral faces features trapezoidal shape of regulated sizes.

EFFECT: higher quality of strips for large-diametre tubes rolled at thick-sheet mill.

4 dwg