Method for case hardening powdered metal parts
AssigneeMidland-Ross Corporation
InventorJoseph A. Riopelle
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Abstract
A method and apparatus is provided for case hardening a porous, powdered metal part by means of a gaseous atmosphere without incurring excessive embrittlement or unacceptable physical distortion of the part. Prior to subjecting the part to the case hardening gaseous atmosphere, the part is heated in an oxidizing atmosphere for a time period sufficent to form oxides of iron which substantially fill the pores at the surface of the part. When the part is later subject to the case hardening gaseous atmosphere, at least one element of the gaseous atmosphere reacts with the oxides of iron and Fe to produce hardenable iron compounds.
Claims4
A process for case hardening a powdered metal part having a porous, sintered body of a heat treatable steel composition comprised primarily of Fe, said process comprising the steps of:
- heating said part in an oxidizing atmosphere for a time period sufficient to form oxides of iron substantially filling the pores of said part at the surface of said part;
- and
- subjecting said part to a predetermined gaseous atmosphere at a predetermined temperature and time sufficient to react with said oxides of iron and said Fe to produce hardenable iron compounds.
Dependencies are inferred from the claim text.