Method and apparatus for joining steel pieces in a hot rolling mill

A method of joining pieces of steel in a hot rolling mill, comprising

• positioning a rear end edge of a first, leading piece of steel adjacent a front end edge of a second, following piece of steel to be joined thereto, adjacent at least two laterally-extending sets of fusing torches;
• independently selecting respective start positions for each of two of said sets of fusing torches, relative to the lateral locations of respective lateral edges of the steel pieces;
• moving said two sets of fusing torches to their respective starting positions;
• moving the sets of fusing torches laterally in a fusing movement, to cause fusing along at least one of said end edges of the steel pieces, with said two sets of torches moving in the same lateral direction, and
• pressing the first and second pieces together longitudinally, to join them at least at the lateral extremities of their meeting end edges.

A method of joining consecutive pieces of steel in a hot rolling mill, comprising

• positioning a rear end edge of a first, leading piece of steel adjacent a front end edge of a second, following piece of steel, adjacent at least two laterally-disposed sets of fusing torches;
• independently selecting a respective traversing speed for each of two of said sets of fusing torches, relative to determined lateral locations of respective lateral edges of the steel pieces;
• moving the sets of fusing torches laterally in a fusing movement, with said two sets moving at their respective selected traversing speeds, to cause fusing along at least one of the adjacent end edges of the first and second steel pieces, and
• pressing the first and second steel pieces together longitudinally to join them at least at the lateral extremities of the meeting of their end edges.

A method of processing steel in a hot rolling mill, comprising:

• forming steel pieces;
• joining successive said steel pieces by a method comprising the steps of conveying the pieces of steel longitudinally along a processing path of the hot rolling mill;
• positioning a rear end edge of a first, leading piece of steel adjacent a front end of a second, following piece of steel to be joined thereto;
• determining lateral location of side edges of the pieces;
• passing multiple fusing torches laterally relative to the processing path along said end edges, in a fusing movement controlled on the basis of said determined side edge locations, causing fusing at at least one of said end edges,
• urging the first and second pieces of steel together longitudinally to join them;
• said fusing movement of the fusing torches being controlled to keep the time between fusing of steel at lateral extremities of the joint, and urging together of said pieces to form the joint less than a predetermined limit time for regrowth of oxide scale;
• rough rolling the joined pieces, and
• finish rolling the rough-rolled joined pieces.

A method of processing steel in a hot rolling mill, comprising:

• forming steel pieces;
• rough rolling the steel pieces;
• joining consecutive rough-rolled steel pieces by a method of conveying the pieces of steel longitudinally along a processing path of the hot rolling mill;
• positioning a rear end edge of a first, leading piece of steel adjacent a front end of a second, following piece of steel to be joined thereto;
• determining lateral location of side edges of the pieces;
• passing multiple fusing torches laterally relative to the processing path along said end edges, in a fusing movement controlled on the basis of said determined side edge locations, causing fusing at at least one of said end edges,
• urging the first and second pieces of steel together longitudinally to join them;
• said fusing movement of the fusing torches being controlled to keep the time between fusing of steel at lateral extremities of the joint, and urging together of said pieces to form the joint less then a predetermined limit time for regrowth of oxide scale;
• and
• finish rolling the joined rough-rolled pieces.

Apparatus for joining consecutive pieces of steel in a hot rolling mill, in which steel pieces are conveyed longitudinally along a processing path, the apparatus comprising:

• multiple fusing torches disposed laterally across the processing path;
• means for driving said fusing torches laterally in a fusing movement, to fuse end edges of steel pieces on the processing path in operation;
• means for determining the locations of side edges of steel pieces on the processing path;
• control means, said control means being connected to said driving means and said side edge location determining means, and adapted to control the driving means to effect independent adjustment of the respective said fusing movements made by various of said fusing torches which operate a the side edges of the processing path, and
• means for pressing consecutive steel pieces on the processing path longitudinally together to join them.

Apparatu for joining consecutive pieces of steel in a hot rolling mill, in which steel pieces are conveyed longitudinally along a processing path, the apparatus comprising

• first and second torch sets, each said torch set comprising at least one fusing torch, disposed laterally across said processing path for fusing at least respective lateral edge portions of steel pieces thereon in operation;
• an adjustable connector, said adjustable connector linking the first and second torch sets;
• means for adjusting the length of said adjustable connector to alter the distance between said torch sets, and
• means for moving the connected torch sets together in the same direction in a lateral fusing movement.