The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 24, 1986
Filed:
Jan. 25, 1984
Friedhelm Kuhn, Muhlheim/Ruhr, DE;
Ruhrgas Aktiengesellschaft, Essen, DE;
Abstract
To harden individual metal parts in a continuous low-energy heat treatment process consisting of clearly separate stages, the part to be heated is placed in a sealed heat treatment box consisting of two layers of porous material separated by a gas-tight barrier. A heat-releasing atmosphere is caused to enter into the material of the two layers during the heating stage, the atmosphere moving from the inner layer of porous material into the box chamber thereby heating the metal part being treated to a diffusion temperature above hardening temperature. An atmosphere releasing components for diffusion is caused to enter the box chamber through the inner layer of porous material during the diffusion stage, with the heat releasing atmosphere continuing to enter the outer layer of porous material. The entry of hot atmosphere into the outer layer of porous material is stopped during the cooling stage, and a cooling atmosphere is caused to enter the box chamber through the inner layer of porous material, to reduce the temperature of the part being heat-treated to the hardening temperature. The temperature having been thus reduced, the part is quenched during the quenching stage by means of a quenching agent preferably following the transfer of the part to a cooling box the hardening agent entering the cooling box through porous material lining the box. A rotating arrangement may be used to transport several heat treatment and cooling boxes through the different treatment stages.