| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of stainless angle steel by which defects such as surface roughening on the surface of the angle steel to be formed is prevented and also the durability of grooved rolls is improved. SOLUTION: In a hot forming process, by threading the angle steel 2 through a selected forming hole 14 which is formed with a roll 11 having recess-shaped grooves and a roll 12 having projecting-shaped grooves, roll forming is performed to the angle steel 2. At this time, high-pressure cooling water 3 is concentrically sprayed from the outlet side of the grooved rolls 1 to the recessed parts 111 of chevrons and projecting parts 121 of chevrons of the selected forming hole 14 and in the vicinities of two right and left end parts 141 where are apart from their respective vertexes. To the whole of the recessed part 111 of the chevrons of the selected forming hole 14 and the whole of the projecting part 121 of the chevrons, the low-pressure cooling water 4 whose pressure is lower than that of the high-pressure cooling water 3 is sprayed. |
