Air Products and Chemicals, Inc.

James Garfield Marsden

Diwakar Garg

Kerry R Berger

Donald J Bowe

Xianming Jimmy Li

Kerry Renard Berger

Donald James Bowe

David L Mitchell, Jr

David Lee Mitchell

A method and apparatus for introducing an oxidant mixed with a carrier gas into pre-heating zone of a continuous furnace for effectively removing lubricant from powder metal compacts prior to sintering at high temperatures. Mixing a controlled amount of a gaseous oxidizing agent such as moisture, carbon dioxide, air or mixtures thereof with a carrier gas and introducing the mixture into the preheating zone of a continuous furnace under controlled conditions accelerates removal of lubricant from powder metal compacts prior to sintering at high temperature by decomposing lubricant vapors into smaller and more volatile hydrocarbons, produces sintered components with close to soot- and residue-free surfaces and with the desired physical properties, prolongs the life of furnace components including muffles and belts, and reduces downtime, maintenance and operating costs.

Method for de-lubricating powder metal compacts

Fine powders of iron with less than 5% by weight graphite, copper, and an organic binder can be formed into shapes having a green density of up to about 7.4 g/cc and sintered in a hydrogen containing atmosphere to yield parts having minimum variations in physical properties. Incorporation of small quantities of copper, e.g. 1% or less by weight, negates variations in physical properties of sintered parts that were subjected to variations in the hydrogen content of the sintering atmosphere.

Carbon steel powders and method of manufacturing powder metal components

The present invention discloses novel nitrogen-hydrogen based atmospheres for sintering steel components in continuous furnaces with consistent quality and properties while prolonging the life of the wire mesh belts, reducing maintenance costs, and improving furnace productivity. Specifically, it discloses the use of a controlled amount of an oxidizing agent such as moisture, carbon dioxide, nitrous oxide, or mixtures thereof along with nitrogen-hydrogen atmospheres. The amount of an oxidizing agent added to the nitrogen-hydrogen atmospheres to pre-condition belt material prior to its use for sintering and to sinter steel components is controlled in such a way that atmospheres become oxidizing to the belt material but reducing to steel components being sintered, specifically in the high heating and cooling zones of continuous furnaces.

Atmospheres for extending life of wire mesh belts used in sintering

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Lenhartsville, PA, United States of America

James Garfield Marsden