Control of hot rolled product cross section under localized temperature disturbances
AssigneeDavid Teng Pong
InventorsDavid Teng Pong, Thomas George Maylor, Erik Mats Raftsjö
Life of this patent
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Abstract
A method of rolling a continuous welded billet having weld joints at successive locations along the billet and wherein the continuous welded billet is advanced through roll pairs of successive roll stands. The rolling conditions in two successive stands are adjusted so that when a weld joint is between the two stands compression is produced at the weld joint causing an increase of cross-sectional area at the weld joint. The rolling condition involves superimposing an increase in roll speed in the upstream roll stand compared to the downstream roll stand based on tracking information of the weld joint.
Claims16
In a method of rolling a continuous welded billet having weld joints at successive locations along the billet and wherein the continuous welded billet is advanced through roll pairs of successive roll stands, the improvement comprising:
- adjusting rolling conditions in two successive stands after a welded joint of a continuous welded billet has passed one stand and is between the two stands to produce compression at said welded joint and an increase of cross-sectional area at said welded joint,
- wherein the rolling conditions are adjusted by increasing speed of the roll pair of said two stands,
- wherein the increase of the speed of the roll pair of the other of the two stands is lower than the increased speed of said one stand.
In a method of rolling a continuous welded billet having weld joints at successive locations along the billet and wherein the continuous billet is advanced through roll pairs of successive roll stands, the improvement comprising:
- adjusting speed of rolls in a roll stand in response to the presence of a weld joint in the billet to produce compression in the billet at the weld joint downstream of the roll stand and upstream of the next downstream roll stand, thereby producing a build-up of material in said weld joint between the stands,
- controlling speed of the rolls at the roll stands by a control computer, and supplying information to said computer regarding location of weld joints and effecting the adjusting of the speed of the rolls in a roll stand when a weld joint is downstream of one stand and upstream of the next successive stand,
- wherein in the absence of a weld joint, the computer regulates the speed of the rolls to produce a rolled billet and when a weld joint is detected, the computer causes increase of the speed of the rolls on the stand upstream of the weld joint to produce compression at the weld joint before the weld joint reaches the next downstream roll stand.
In a method of rolling a continuous welded billet having weld joints at successive locations along the billet and wherein the continuous welded billet is advanced at high temperature from a welder, the weld joints being at a higher temperature than the rest of the billet, the welded billet being advanced through roll pairs of successive roll stands of a rolling mill, the improvement comprising:
- adjusting rolling conditions in two successive roll stands, in an upstream region of the roll mill at which the billet and weld joints are at high temperature, said rolling conditions being adjusted such that after a welded joint of the continuous welded billet has passed one stand and is between the two successive stands to produce compression at said welded joint of high temperature and cause bulging of the welded joint to produce an increase of cross-sectional area at said welded joint such that at the end of the rolling mill, the weld joints of the now rolled billet will have uniform size and proportion.
Dependencies are inferred from the claim text.