Method for quenching railway rail heads
AssigneeChemetron-Railway Products, Inc.
InventorsEmmerich E. Wechselberger, Ralph S. Frost
Life of this patent
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Abstract
A method of air quenching a railway rail with an apparatus develops a pearlite microstructure in the head of the longitudinally travelling rail as it travels under the apparatus. A primary air chamber at a controlled pressure provides air to the top and side surfaces of the rail heads. A secondary air chamber at a separately controlled pressure provides air to the shoulders of the rail heads. More than one quench unit may be used in series, in which case the pressures in the primary air chambers may progressively increase to increase the cooling rate.
Claims11
A method of air quenching the heated head of an axially moving railway rail from austenizing temperatures to develop a pearlite microstructure in the head, and wherein the rail head has a top running surface, laterally opposite side surfaces, and a shoulder surface between each side surface and the top running surface, said method comprising the steps of:
- passing the rail head longitudinally through a plurality of quenching units which are longitudinally aligned and each of which includes first housing means defining primary quenching fluid chambers having fluid discharge means operative to confront only the top and side surfaces of the rail head when passed through the quenching units, and second housing means defining a pair of secondary quenching fluid chambers having fluid discharge means operative to confront only the shoulder surfaces of the rail head when passed longitudinally through the quenching units;
- introducing quenching air into the primary and secondary chambers of the first of the aligned quench units so as to cool only the top and side surfaces of the rail head at a first cooling rate and simultaneously cool only the shoulder surfaces of the rail head at a lower cooling rate;
- and
- introducing quenching air into the primary and secondary chambers of each successive quench unit so as to cool only the top and side surfaces of he rail head at a progressively faster cooling rate in each successive quenching unit, and simultaneously cool only the shoulder surfaces of the rail head in each successive quench unit at a lower rate than the cooling rate for the top and side surfaces.
A method of air quenching the heated head of an axially moving railway rail from austenizing temperatures to develop a pearlite microstructure in the head, and wherein the rail head has a top running surface between each side surface and the top running surface, said method comprising the steps of:
- passing the rail head longitudinally through a plurality of longitudinally aligned quenching units each of which includes first housing means defining a primary quenching air chamber having a perforated plate defining a concave discharge surface for confronting only the top and side surfaces of the rail head when passed through the corresponding quench unit, and second housing means defining a pair of secondary quenching air chambers discrete from the primary quenching air chambers and each having a perforated plate defining a concave discharge surface for contronting only the shoulder surfaces of the rail head when passed longitudinally through the corresponding quenching unit;
- introducing quenching air into the primary and secondary quenching air chambers of the first quench unit so as to cool only the top and side surfaces of the rail head at a first cooling rate and simultaneously cool only the shoulder surfaces of the rail head at a lower cooling rate;
- and
- introducing quenching air into the primary and secondary quenching air chambers of each successive quench unit so as to cool only the top and side surfaces of the rail head at a progressively faster cooling rate in each successive quenching unit, and simultaneously cool only the shoulder surfaces of the rail head in each successive quench unit at a lower rate than the cooling rate for the corresponding top and side surfaces.
Dependencies are inferred from the claim text.