Induction heating large, thick walled steel pipe - followed by controlled, brief surface quenching and tempering

摘要

Plant for the adjustable cooling of a long hot tubular metal workpiece, e.g. a pipe, fed continuously through a coolant zone at a controlled speed so nozzles spray a coolant, e.g. water, onto the pipe surface. The cooling zone has nozzles spraying water at an angle inclined in the direction of pipe travel; and the length of the cooling zone is adjusted by a curtain which can be moved along the pipe. The adjustable curtain is pref. a water curtain provided by a ring nozzle spraying water radially onto the pipe; or by a ring nozzle formed using several segments fed from a common water source. Plant is used e.g. for the controlled quenching of large dia. steel pipes with thick walls, using induction heating. All the process parameters can be accurately controlled.