Rolling apparatus for producing angle from steel strip and method of rolling the angle using the same

A method of producing an angle steel from a steel strip by using a current-applying heating apparatus, a universal mill, and two high mills, the method comprising the steps of:

• disposing, prior to starting the rolling of the steel strip, a pre-stage pair and a post-stage pair of upper and lower current supply rolls contained in the current-applying heating apparatus so that the two pairs of current supply rolls are close to each other in the running direction of the steel strip;
• halting the steel strip when the steel strip is bitten into by the post-stage current supply rolls and applying a current while moving the pre-stage current supply rolls in a direction opposite to the running direction of the steel strip;
• running the steel strip at the rolling speed when the steel strip reaches a specific temperature;
• at the same time releasing the steel strip from the post-stage current supply rolls, and applying a current to heat the steel strip between the pre-stage current supply rolls and the universal mill, or between the pre-stage current supply rolls and the two high mills;
• pressing the steel strip in the cross direction thereof and pressing the steel strip in the thickness direction thereof to thereby increase a thickness of the steel strip at the center of the width thereof by using the universal mill, in which are disposed a pair of vertical rolls having grooves formed thereon and a pair of horizontal rolls, one of which has a groove formed on the center of the longitudinal length of the roll;
• and
• finishing the steel strip into an angle by using two or more passes of the two high mills.

A method of rolling an angle steel from a steel strip by using a current-applying heating apparatus, a universal mill, and two high mills, the method comprising the steps of:

• disposing, prior to starting the rolling of the steel strip, a pre-stage pair and a post-stage pair of upper and lower current supply rolls contained in the current-applying heating apparatus so that the pairs of the current supply rolls are close to each other in the running direction of the steel strip;
• halting the steel strip when the steel strip is bitten into by the post-stage current supply rolls and applying a current while moving the pre-stage current supply rolls in a direction opposite to the running direction of the steel strip;
• running the steel strip at the rolling speed when the steel strip reaches a specific temperature;
• at the same time releasing the steel strip from the post-stage current supply rolls, and applying a current to heat the steel strip between the pre-stage current supply rolls and the universal mill, or between the pre-stage current supply rolls and the two high mills;
• pressing the steel strip in the cross direction thereof and pressing the steel strip in the thickness direction thereof to thereby increase a thickness of the steel strip at the center of the width thereof by using the universal mill, in which are disposed one pair of vertical rolls having grooves formed thereon and one pair of horizontal rolls, one of which has a groove formed on the center of the longitudinal length of the roll, and the other one of which has a projection formed on the center of the longitudinal length of the roll;
• and
• finishing the steel strip into an angle by using one or more passes of the two high mills.