Patent ID: 8986605
Filing Date: 2015-03-24
Classification: B22F,F27B,F27D

Abstract:
1. A method for sintering steel components in a furnace at a one or more operating temperatures, the method comprising: providing the furnace comprising a belt comprising a wire mesh material wherein the steel components are supported thereupon; pre-conditioning the furnace and belt to one or more pre-conditioning temperatures ranging from about 1400° F. to about 1700° F.; maintaining the belt at a stress-relief temperature ranging from about 1700° F. to about 1750° F. for at least one belt cycle in an atmosphere comprising nitrogen, hydrogen, and endothermic gas; heating the furnace and belt in absence of a metal component to the normal operating temperature ranging from about 1800° F. to about 2200° F. in an atmosphere comprising nitrogen, hydrogen, and endothermic gas; providing one or more steel components on the belt; and sintering the components in the furnace in an atmosphere comprising nitrogen, hydrogen, and an effective amount of endothermic gas at the one or more operating temperatures ranging from about 1800° F. to about 2200° F. wherein the amount of endothermic gas in the atmosphere is such that it is oxidizing to the wire mesh material and reducing to the steel components and the dew point of the atmosphere is greater than or equal to −40° F., and wherein the pre-conditioning, maintaining, and heating steps are conducted in the absence of the steel components and wherein the pre-conditioning, maintaining, and heating steps are conducted prior to the sintering step, and wherein the temperature is increased from the pre-conditioning step to the maintaining step at a rate of about 100° F. to about 300° F. per belt cycle.