Method and device for hardening work pieces and workpieces hardened according to said method
AssigneeALD Vacuum Technologies GmbH
InventorsVolker Heuer, Klaus Loeser, Gunther Schmitt, Gerhard Welzig
Life of this patent
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Abstract
The invention relates to a method and device for thermally treating workpieces, the device including a cooling chamber and two or more carburizing chambers in which the work pieces are heated to a temperature of 950 to 1200° C. by means of direct heat radiation from a heating device.
Claims12
A device for hardening metallic workpieces comprising a rack designed to hold workpieces arranged in one layer or row, two or more carburizing chambers, at least one cooling chamber, a lock chamber arranged between the carburizing chambers and the cooling chamber, and a transfer system for handling racks for the workpieces, wherein the cooling chamber can be connected to the lock chamber via a vacuum gate valve, each of the carburizing chambers can be connected to the lock chamber via thermal insulation gate valves, and each of the carburizing chambers has a receptacle for the rack and at least two heating elements consisting of graphite or carbon-fiber-reinforced carbon, said heating elements positioned to emit radiation directly onto the surface of each of the workpieces at an average solid angle of 0.5 π to 2 π, and said heating elements are meandering heaters having a U-shaped serpentine form disposed on a bottom side and a top side of each of the carburizing chambers,
- wherein the lock chamber further comprises a rack repository, and
- the cycle time based on one workpiece is 5 to 120 seconds.
A hardening system comprising (i) metallic workpieces arranged in a single layer on a grid-like pallet having an opening ratio of greater than 60% and (ii) a device for hardening workpieces comprising four or more carburizing chambers, at least One cooling chamber, a lock chamber arranged between the carburizing chambers and the cooling chamber, a transfer system, and a pallet repository, wherein die cooling chamber can be connected to the lock chamber via a vacuum gate valve, each of the carburizing chamber can be connected to the lock chamber via thermal insulation gate valves, and each of the carburizing chambers consists essentially of (i) lined walls;
- (ii) a gate valve;
- (iii) a receptacle for the grid-like pallet and (iv) at least two heating elements consisting of graphite or carbon-fiber-reinforced carbon and (v) connections far gas and vacuum, said heating elements positioned to emit radiation directly onto the surface of each of the workpieces at an average solid angle of 0.5 π to 2 π and said heating elements are meandering heaters having a U-shaped serpentine form disposed on a bottom side and a top side of each of the carburizing chambers,
- wherein the cycle time based on one workpiece is 5 to 120 seconds.
Dependencies are inferred from the claim text.