Caterpillar Inc.

Other

Sheryl A Tipton

Gary D Keil

Wayne A Supak

Ronald G Morgan

Gary L Biltgen

Gregory S Holloway

Paul E Hoernlein

David R Gromer

Philip A Newman

Dissociated ammonia carrier gas used as a reference gas is obtained from an ammonia dissociator which also provides dissociated ammonia carrier gas to a nitriding furnace whereby the source of ammonia supply gas is the same. An oxygen probe is used to regulate the nitriding potential of a nitriding furnace and atmosphere for process control and high quality nitrided parts. The method further includes correlating the probe mV output signal to a nitriding potential and adjusting the ratio of ammonia supply gas to dissociated ammonia carrier gas at the inlet of the nitriding furnace.

Method for controlling a nitriding furnace

A steel article is formed of a steel material containing from about 0.08 to about 0.35 carbon and is characterized by having a plurality of carbides dispersed on at least one pre-selected surface area of the article, with the surface carbides being dispersed within a predominantly lower bainitic matrix. A method for forming the steel article having high hardness and higher toughness includes carburizing the article at a temperature and for a period of time, in an atmosphere having a carbon potential, sufficient to form carbides and austenite on at least one preselected surface of the article, and then quenching the carburized article to a temperature below the Ar.sub.1 temperature and above the M.sub.s temperature of the steel material for a time sufficient to transform a major portion of the austenite in the preselected surface area microstructure to lower bainite. The steel article has an equivalent Knoop 500 gram maximum particle hardness of at least 900 and a Charpy unnotched, room temperature toughness of at least 50 Joules, thereby providing an article having both high hardness and improved toughness properties.

Steel article having high hardness and improved toughness and process

A process for automated measurement of ammonia in a gas mixture containing ammonia gas and one or more water-insoluble gases includes providing a water reservoir adapted for supplying water therefrom through a first solenoid valve and providing a measurement vessel adapted for receiving water. The vessel is adapted for draining the water therefrom through a second solenoid valve. The vessel is also adapted for receiving the gas mixture through a third solenoid valve and purging the gas mixture from the vessel through a fourth solenoid valve. The vessel is adapted for maintaining the gas in the vessel and receiving water thereinto in an amount sufficient to dissolve the ammonia gas contained in the gas mixture, into the water, and allowing a differential pressure between the gas mixture and the water containing dissolved ammonia to be measured. The process also includes providing a measurement vessel adapted for allowing height of water within the vessel to be measured, providing means for measuring height of water within measurement vessel, and providing recording means for converting the measured height signal to an ammonia concentration value.

Process for automated measurement of ammonia content in a gas mixture

Apparatus for automated measurement of ammonia concentration in a gas

A quench cooling effectiveness apparatus for continuous monitoring of a heat treat quench system and method of operation is provided. The apparatus preferably includes first and second heat conductive sheaths having temperature sensors installed therein. The heat conductive sheaths are thermally insulated from each other with a heat resistive sheath. A microprocessor is preferably connected to said sensors, applies a known current to one sensor, and calculates a cooling effectiveness of the heat treat quench system from the temperature of the two sensors and the known applied current.

Quench cooling effectiveness apparatus for continous monitoring

A quench system cooling effectiveness meter including a reference sensor and a measurement sensor is disclosed. The reference sensor and the measurement sensor are included in a resistance bridge. The amount of heat that can be removed by the quench system from the measurement sensor is recorded to determine the cooling effectiveness of the quench system. The meter can be moved to different locations within the quench system to measure cooling variations within the system as a function of location.

Growing community of inventors

East Peoria, IL, United States of America

Sheryl A Tipton