Abstract: An apparatus is provided for quenching a hollow-bodied piece of steel with an opening at each end thereof, such as a steel pipe, which comprises exterior and interior quenching means. The exterior quenching means includes means for directing a cooling medium in a substantially circumferential flow pattern around the exterior of a steel pipe. In one embodiment the exterior quenching means includes means for separately directing a cooling medium in a substantially circumferential flow pattern at variable flow rates around the exterior segments of a steel pipe. The flow rate around each pipe segment may be varied with the thickness of the segment. The exterior cooling means may comprise a plurality of deflector plates to achieve the circumferentially directed flow of the cooling medium about the pipe.

Abstract: A process is provided for heat treating steel in which each segment of a piece of steel is quenched in a quenching zone by directing the flow of a sufficient amount of a cooling medium against a surface of each segment to lower the temperature of the segment to a desired temperature while vaporizing substantially all of the cooling medium to create a vapor blanket around at least one surface of each segment so cooled. In one embodiment, steel pipe is heated above its critical transformation temperature and then each longitudinal segment of the pipe is sequentially quenched by substantially simultaneously sending a sufficient amount of water against the inside and outside surfaces of each segment to reduce the temperature of the segment to within a predetermined range while vaporizing substantially all of the water to create a steam blanket around the segment.

Abstract: A process is provided for heat treating steel in which each segment of a piece of steel is quenched in a quenching zone by directing the flow of a sufficient amount of a cooling medium against a surface of each segment to lower the temperature of the segment to a desired temperature while vaporizing substantially all of the cooling medium to create a vapor blanket around at least one surface of each segment so cooled. In one embodiment, steel pipe is heated above its critical transformation temperature and then each longitudinal segment of the pipe is sequentially quenched by substantially simultaneously sending a sufficient amount of water against the inside and outside surfaces of each segment to reduce the temperature of the segment to within a predetermined range while vaporizing substantially all of the water to create a steam blanket around the segment.