Continuous rolling method of billet and apparatus therefor

A continuous rolling apparatus comprising:

• a first line;
• a second line;
• a line-connecting unit for connecting the first line and the second line in a manner such that the first line and the second line are either substantially parallel to each other or substantially at right angles to each other;
• a stationary flash-butt welder provided in the first line for joining a rear end of a preceding billet with a front end of a succeeding billet to produce a double-length billet having a first welded portion;
• a travelling flash-butt welder provided in the second line for joining a front end of the double-length billet with a rear end of a continuous billet to produce an extended continuous billet having a second welded portion;
• a travelling grinding machine for grinding burrs on the first welded portion and the second welded portion;
• an induction heater for heating the extended continuous billet;
• and
• a continuous rolling mill for continuously rolling the extended continuous billet.

A continuous rolling method comprising:

• a first flash-butt welding step of using a stationary welder to join a rear end of a preceding billet with a front end of a succeeding billet to produce a double-length billet;
• a second flash-butt welding step of using a travelling welder, which is arranged in series with the stationary welder, to join a front end of the double-length billet with a rear end of a continuous billet to produce an extended continuous billet having a welded portion;
• a step of grinding the welded portion of the extended continuous billet to remove a burr therefrom;
• a step of heating the extended continuous billet from which the burr has been removed;
• and
• a step of continuously rolling the extended continuous billet through a series of rolling mills.

A continuous rolling method comprising:

• a first flash-butt welding step of using a stationary welder provided in a first line to join a rear end of a preceding billet with a front end of a succeeding billet to produce a double-length billet;
• a step of intermittently transferring the double-length billet to a second line matching a rolling line;
• a second flash-butt welding step of using a travelling welder provided in the second line to join a front end of the double-length billet with a rear end of a continuous billet to produce an extended continuous billet having a welded portion;
• a step of grinding the welded portion of the extended continuous billet to remove a burr therefrom;
• a step of heating the extended continuous billet from which the burr has been removed;
• and
• a step of continuously rolling the extended continuous billet through a series of rolling mills.