The Algoma Steel Corporation, Limited

Murray A Nott

Robert J Ackert

Kenneth Overman

A method and apparatus for controlling the shape of a hot railroad rail during accelerated cooling of the rail head. The railroad rail is cooled along its web-base junction at a rate which achieves a pre-selected degree of shape control, while avoiding over-cooling of the upper portion of the web or the tips of the rail base. The apparatus comprises spray means for applying selected volumes of coolant to the web-base junction of the rail oriented about the periphery of the rail. Such apparatus may be used to shape a rail during the accelerated cooling thereof in line with a rolling mill.

Method for shape control of rail during accelerated cooling

An improved method for the manufacture of hardened railroad rails comprises the steps of forming a railroad rail from an alloy steel of a preselected chemical composition, force cooling the rail from a preselected cooling start temperature above about the austenite-to-ferrite transformation temperature, terminating the force cooling when the temperature of rail reaches a preselected cooling stop temperature, and before a substantial volume fraction of the austenite in the rail head has transformed to pearlite, and holding the rail under substantially isothermal conditions until the austenite-to-pearlite transformation is complete. The chemical composition of the alloy steel is selected such that the austenite-to-pearlite reaction occurs earlier in time than the austenite-to-bainite reaction under the substantially isothermal conditions. The use of this method makes avoidance of bainite easier to achieve, so relatively simple and inexpensive process control equipment can be utilized.

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Sault Ste. Marie, Canada

Murray A Nott