Caterpillar Inc.

Other

Holcroft/loftus Inc.

Gary D Keil

Sheryl A Tipton

Wayne A Supak

Ronald G Morgan

Gregory S Holloway

Loren D Thompson, Deceased

Gary L Biltgen

Thomas E Clements

Charles F Berndt

John B Walenta

Fredric A Woldow

Steven M Cross

Randall R Conklen

Philip A Newman

John W Smith

Timothy M Hoefft

Paul E Hoernlein

David R Gromer

Paul R Luebbers

An article and method for forming an article having a hard-finished surface including a predetermined density of carbides to improve pitting and wear resistance and to significantly increase the overall life of the article. This method comprises selecting a carburizing grade material to form an article, carburizing the article to form a microstructure on at least one portion of the article having a predetermined density of carbides dispersed in the microstructure to a predetermined depth, quenching the article to form a hardened matrix dispersed with carbides and hard finishing the article to form the surface, the surface having at least approximately 20% by volume fraction carbides dispersed in the hardened matrix.

Carbide method and article for hard finishing resulting in improved wear resistance

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

The present automated system for carburizing a component decreases the energy used to manufacture the component. The operations of heating the component in a first heating apparatus, forging the component in a forge and transferring the hot forged component directly to a second heating apparatus having a controlled atmosphere, increasing the temperature of the component, absorbing carbon within the component to a predetermined surface carbon content and depth and directly transferring the component to a quenching chamber and quenching the component defining a heat treated component.

Automated system for carburizing a component

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 control system for a gas generator is disclosed. The control system includes an automotive type oxygen sensor that produces a signal responsive to the oxygen content of a product gas. The automotive type oxygen sensor is connected to a controller and is installed in the gas generator so that the sensor tip is in the product gas, downstream of a first heat exchanger. Preferably, the installation of the automotive sensor is at a point where the product gas has been cooled to at least 1500.degree. F. at a rate of at least 4000.degree. F. The controller produces an output signal responsive to the oxygen sensor signal. A trim valve receives the controller output signal and responsively varies an input gas to vary the composition of the product gas.

Automatic control of endothermic gas generators using low cost oxygen

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.

Quench system cooling effectiveness meter and method of operating same

A heat treat furnace system 20 for heat treating metal workpieces includes a rotary carburizing chamber 24 containing a carburizing atmosphere, a cooling chamber 40A or 40B adjacent the carburizing chamber 24, a gas barrier device 50 cooperating with the cooling chamber opening and the carburizing chamber outlet for impeding movement of atmosphere therethrough; and transfer mechanisms for operatively moving at least one selected workpiece from the carburizing chamber 24 to the cooling chamber 40A or 40B and vice versa, and from the cooling chamber 40B to the equalizing chamber 26 and vice versa. The carburizing chamber 24 has a circular rotatable hearth for supporting an array of workpieces, and an inlet for loading the workpieces into the carburizing chamber 24. The cooling chamber 40A or 40B also has means for providing a protective atmosphere within it. This arrangement provides a system that can perform different heat treat operations, either singly or simultaneously, and/or the same heat treat operation on different piece parts. For example, the system can simultaneously perform a process where carbides are desired and a process where carbides are not desired.

Heat treat furnace system for performing different carburizing processes

A control system for heat-treating parts in a furnace structure is provided. A plurality of processing chambers, each having at least one part position, are adapted to simultaneously process a plurality of parts each for a respective predetermined processing time. A memory device stores first records representing processing times associated with each of the parts within each processing chamber, second records representing a desired processing path associated with each part through at least one processing chamber, and third records representing the number and location of occupied part positions within each processing chamber. A computerized control center calculates desired processing times associated with at least one processing chamber for a new part to be processed in the processing chamber. Additionally, the computerized control center determines an entrance time for the new part to enter the furnace structure, in response to the first, second, and third records, and to the calculated desired processing times.

Control system for scheduling parts in a heat-treating process

Carburized low silicon steel article and process

A continuous carburizing furnace system is disclosed having at least two series-connected rotary furnaces. The rotary carburizing furnace, a rotary equalizing furnace, and a rotary diffusion furnace which may be included between the carburizing and equalizing furnaces, allow trays of parts to be discharged from any position at any time by suitable rotation of their hearths, thus allowing parts with different cycle times to be run simultaneously in each rotary furnace. Each donut-shaped rotary furnace includes one or more captive chain type pusher mechanisms mounted in vertical fashion within a central area or hole, and the rotary carburizing furnace is multi-zoned and includes wall-mounted fans for uniform circumferential control of the gaseous atmosphere within its annular chambers. Two different quenching apparatuses and a slow cool assembly adjacent multiple outlets of the equalizing furnace permit the use of different cooling/quenching processes on selected parts, and parts may also be returned from the slow cool assembly to the equalizing furnace for reheating.

Growing community of inventors

Elmwood, IL, United States of America

Gary D Keil