MANUFACTURE OF WIDE FLANGE SHAPE WITHOUT WEB WAVE

摘要

PURPOSE:To manufacture a wide flange shape without web wave by cooling flanges so that difference in the mean temp. of flanges from the mean temp. of a web is lower than the limit temp. difference that is shown by a prescribed equation at the time of starting natural cooling after finish rolling. CONSTITUTION:The flanges 1 of the wide flange shape are cooled only at the time of rolling and, at this time, the flanges 1 are cooled so that the difference in the mean temp. of flanges 1 from the mean temp. of the web 2 is lower than DELTATa that is shown by the prescribed equation at the time of stating natural cooling after finish rolling. Where, sigmacr=Min[3.6E(Tw/Hw)<2> sigmaY], Aw, Af: cross- sectional area of web and flange, E: Young's modulus at the room temp., tw: thickness of web, Hw: inside width of web, sigmaY: yield stress of web at the room temp., DELTATa: temp. ( deg.C). In this way, the bending of the web 2 after cooling is prevented. And, at the time of rolling, after finish rolling or at the time of rolling and after finish rolling, water cooling of flange is executed using a flange cooling device 3.