gorman

Claim 1

A METHOD OF TEMPERING THICK WALLED TUBULAR ARTICLES COMPRISING UNIFORMLY HEATING THE OUTSIDE OF THE ARTICLE WITH PRODUCTS OF COMBUSTION TO RAISE THE TEMPERATURE OF THE OUTSIDE OF THE ROLL IN THE RANGE OF 1425* TO 1650* F., SIMULTANEOUSLY APPLYING A SEPARATE SOURCE OF HEATING TO THE INSIDE BORE OF THE ARTICLE TO RAISE THE TEMPERATURE OF THE INSIDE OF THE ARTICLE IN THE RANGE OF 1395* TO 1550* F. AND TO MAINTAIN A TEMPERATURE GRADIENT BETWEEN THE INNER BORE SURFACE AND THE OUTSIDE SURFACE SO THAT THE OUTSIDE SURFACE IS ALWAYS 30 TO 100*F. HIGHER THAN THE BORE SURFACE TEMPERATURE HOLDING THE ARTICLE UNDER HEAT UNTIL THE ENTIRE BODY OF THE ROLL IS RAISED ABOVE ITS CRITICAL TEMPERATURE, QUENCHING THE ARTICLE ON THE OUTSIDE AND IN THE BORE RAPIDLY AND UNIFORMLY TO OBTAIN A DEEP PENETRATING HARDNESS IN THE OUTSIDE AND THE INSIDE SURFACES OF THE ARTICLE TO COOL THE ARTICLE BELOW 300*F., THEREAFTER TEMPERING THE ARTICLE TO RELIEVE STRESSES BY SEPARATELY CONTROLLED HEATING ON THE OUTSIDE AND IN THE INSIDE OF THE BORE TO DEVELOP TEMPERATURES IN THE RANGE OF 250* TO 1150*F. ON THE OUTSIDE SURFACE AND THE INSIDE SURFACE AT 10 TO 100*F. ABOVE THE OUTSIDE SURFACE, CONTINUING THE DRAWING HEATING FOR A PERIOD OF HOURS TO RELIEVE THE STRAIN IN THE ARTICLE THEN CUTTING OFF THE HEAT AND QUENCHING THE ARTICLE IN THE FURNACE WITH THE CIRCULATION OF COOLING AIR AND COMBUSTION GASES UNTIL THE MEDIAL BODY TEMPERATURE OF THE ARTICLE IS REDUCED AT LEAST 50*F. BELOW THE TEMPERING TEMPERATURE.

Claim 2

A METHOD OF TEMPERING THICK WALLED TUBULAR ARTICLES COMPRISING UNIFORMLY HEATING THE OUTSIDE OF THE ARTICLE WITH PRODUCTS OF COMBUSTION TO RAISE THE TEMPERATURE OF THE OUTSIDE OF THE ROLL IN THE RANGE OF 1425* TO 1650* F., SIMULTANEOUSLY APPLYING A SEPARATE SOURCE OF HEATING TO THE INSIDE BORE OF THE ARTICLE TO RAISE THE TEMPERATURE OF THE INSIDE OF THE ARTICLE IN THE RANGE OF 1395* TO 1550* F. AND TO MAINTAIN A TEMPERATURE GRADIENT BETWEEN THE INNER BORE SURFACE AND THE OUTSIDE SURFACE SO THAT THE OUTSIDE SURFACE IS ALWAYS 30 TO 100*F. HIGHER THAN THE BORE SURFACE TEMPERATURE HOLDING THE ARTICLE UNDER HEAT UNTIL THE ENTIRE BODY OF THE ROLL IS RAISED ABOVE ITS CRITICAL TEMPERATURE, QUENCHING THE ARTICLE ON THE OUTSIDE AND IN THE BORE RAPIDLY AND UNIFORMLY TO OBTAIN A DEEP PENETRATING HARDNESS IN THE OUTSIDE AND THE INSIDE SURFACES OF THE ARTICLE TO COOL THE ARTICLE BELOW 300*F., THEREAFTER TEMPERING THE ARTICLE TO RELIEVE STRESSES BY SEPARATELY CONTROLLED HEATING ON THE OUTSIDE AND IN THE INSIDE OF THE BORE TO DEVELOP TEMPERATURES IN THE RANGE OF 250* TO 1150*F. ON THE OUTSIDE SURFACE AND THE INSIDE SURFACE AT 10 TO 100*F. ABOVE THE OUTSIDE SURFACE, CONTINUING THE DRAWING HEATING FOR A PERIOD OF HOURS TO RELIEVE THE STRAIN IN THE ARTICLE THEN CUTTING OFF THE HEAT AND QUENCHING THE ARTICLE IN THE FURNACE WITH THE CIRCULATION OF COOLING AIR AND COMBUSTION GASES UNTIL THE MEDIAL BODY TEMPERATURE OF THE ARTICLE IS REDUCED AT LEAST 50*F. BELOW THE TEMPERING TEMPERATURE.