Abstract: A method and assembly for heat treating a railway rail is provided which maintains balanced thermal and metallurgical deformations about rail neutral axes during the heat treating process to produce a substantially straight rail with only minimal requirements for subsequent mechanical steps for distortion compensation. The method comprises the first step of preheating the overall rail including head, web and flange portions to a first preselected temperature below a metallurgical transformation temperature. A second step comprises heating rail head and flange portions to preselected temperatures above the metallurgical transformation temperature with a balanced thermal deformation about rail neutral axes. A third step comprises quenching the rail head and flange portions to produce a desired metallurgical structure in the rail head portion for improved wear characteristics while still maintaining a balanced thermal deformation about the axes. A fourth step comprises after-cooling the entire rail.

Abstract: There is disclosed herein apparatus and method for heating metallic tubing having a thickened portion, by passing the same through an induction heater energized with power at a relatively high frequency whereby the temperature of the body of the tubing rises at a faster rate than the temperature of the said thickened portion and passing the said tubing through an induction heater energized with power at a relatively low frequency to cause the temperature of said thickened portion of the tubing to rise at a faster rate than the temperature of the body of the tubing, the ratio of the power applied at said low frequency relative to the power applied at said high frequency being such that said body and said thickened portion attain substantially the same predetermined final temperature upon exiting from said apparatus.