| 摘要 |
PURPOSE:To improve the ridging of continuously cast ferrite stainless steel by rolling a cast steel piece with rolls of different diameters by controlling the number and size of crystal grains during hot rolling in terms of the thickness and equiaxed crystal grain ratio of cast steel. CONSTITUTION:A continuously cast steel piece, the equiaxed crystal grain ratio and thickness of which are controlled to more than 50% and more than 130 mm preferably, respectively, is heated to 1250 deg.C or less and then rolled at a draft of more than 20 % by using a continuous hot rolling machine provided with one or more rolling machines with rolls of different diameters, or working rolls of a different diameter ratio of more than 15 %, to obtain hot rolled steel plate. Thus, the ferrite stainless steel is subjected to a specific deformation in the direction of plate thickness and the deformation restricted by rolls comes, therefore, deeply into the inside of plate, whereby greatly improving the ridging. |
