Continous hot rolling method and joining method of sheet bar
AssigneeKawasaki Steel Corporation
InventorsNobuhiro Ito, Toshisada Takechi, Hideo Takekawa, Fujio Aoki, Hiroyuki Yoshimura, Norio Takashima, Masanori Ebihara, Masanori Kitahama
Life of this patent
Estimating the term…
Abstract
In the continuously hot rolling of plural sheet bars, in order to simply and surely join the sheet bars to the back end portion of the preceding sheet bar and the front end portion of the succeeding sheet bar are prejoined by butting to each other at an entrance side of a finish rolling mill and then bitten into the finish rolling mill, during which the joining of the sheet bars are promoted to conduct the continuous rolling.
Claims9
In a method of continuously hot rolling sheet bars by continuously feeding preceding sheet bar passed through a rough rolling strep and a succeeding transferred sheet bar followed thereto into a finish rolling mill, the improvement wherein a front end portion of the succeeding sheet bar is butted to a back end portion of the preceding sheet bar before an entrance side of the finish rolling mill so as to contact at least both widthwise side edge regions in the front end portion of the succeeding sheet bar with at least both widthwise side edge regions in the back end portion of the preceeding sheet bar at a compression stress of not less than 1 kgf/mm.sup.2, and then the sheet bars are continuously fed into the finish rolling mill at such a butted state.
In a method of continuously hot rolling sheet bars by continuously feeding a preceding sheet bar passed through a rough rolling step and a succeeding transferred sheet bar followed thereto into a finish rolling mill, the improvement wherein a back end portion of the preceeding sheet bar and a front end portion of the succeeding sheet bar are cut before an entrance side of the finish rolling mill into such a shape that at least both widthwise side edge regions in the front end portion of the succeeding sheet bar are contacted with at least both widthwise side edge regions in the back end portion of the preceding sheet bar and thereafter butted and preliminarily joined with each other and then continuously fed into the finish rolling mill at such a butted state.
In a method of joining sheet bars by joining a back end portion of a preceding sheet bar to a front end portion of a succeeding sheet bar in a transfer line on an entrance side of a finish rolling mill after rough rolling in the hot rolling, the improvement wherein a strong reduction is applied to each of the back end portions of the preceding sheet bar and the front end portion of the succeeding sheet bar to gradually reduce a thickness of each end portion in a tapered form, and the thus tapered portions of the preceding and succeeding sheet bars are overlapped with each other and subjected to a spot welding before the entrance side of the finish rolling mill.
Dependencies are inferred from the claim text.