| 摘要 |
PURPOSE:To prevent deformation and bending caused by solution heat treatment and to facilitate supply and pulling out of a stock in straightening stage by immediately winding a half-formed product formed by hot rolling into a coil. CONSTITUTION:A heated stock is worked to obtain a 1st half-formed product 2 in which a pair of flange parts 3 and a web part 4 are in a straight lined shape, an about right angled projected part 6 is formed at corners connecting the flange parts 3 and web part 4; further, a recessed part 7 is formed on the backside of the projected part 6, and thicknesses of the flange parts 3 and web part 4 are nearly equal to those of a product and then the 1st half-formed product 2 is immediately wound into a coil and solution heat treatment is performed on the product 2 in a coil situation. Then, the 1st half-formed product 2 is subjected to two or more passes of hot forming by hot rolling rolls to bend a corner part 5 by an about right angle to form a 2nd half-formed product. In the final finish stage, a pair of horizontal rolls 16 and a pair of vertical rolls 17 form a channel steel 20 having parallel flange parts 3 and the flat web part 4. |
