Abstract: A method for forming a profile having at least three consecutive concave surfaces in an internal surface of a metal part includes piercing the metal part to create at least three consecutive concave surfaces. First, second and third concave surfaces respectively have first, second and third radii of curvature. The second concave surface is between the first and third concave surfaces. The second radius of curvature is different from the first and third radii of curvature. The method includes carburizing the metal part, grinding the second concave surface, and linear broaching the first and third concave surfaces with an abrasive-covered broach. A method for forming a groove in a surface of a metal part includes broaching the surface to create a groove having a groove surface, carburizing the metal part, and broaching a portion of the groove surface with an abrasive-covered broach after carburizing the metal part.

Abstract: A surface treating method for a golf club head made of carbon steel basically has one nitriding step and two oxidizing steps. The method further has polishing, sandblasting and rinsing steps and so on processed prior to or between the basic steps, and then has polishing and oil immersing steps and so on processed after the basic steps. The finished golf club head has uniform dark appearance and also has good corrosion resistance and abrasion resistance. Furthermore, the surface of the finished golf club head does not peel off. Moreover, the method also has advantages including low pollution and low cost.

Abstract: In order to provide a further uniform carburizing treatment to an article to be treated, a carburizing treatment apparatus which performs carburizing treatment by heating the article to be treated in a treatment chamber, the inside of which is under reduced pressure and in a carburizing gas atmosphere, includes a temperature measurement means for measuring temperatures in a plurality of regions inside the treatment chamber and a temperature adjustment means for individually adjusting temperatures in the plurality of regions on the basis of measurement results of the temperature measurement means so that the article to be treated is given a uniform carburizing treatment.

Abstract: Described herein is a method that can be used for heat treating a metal in at least one of the following processes: carburizing, carbonitriding, nitrocarburizing, and neutral carbon potential annealing operations that are used in a 1 atmosphere pressure furnace and in an atmosphere that is oxygen free and comprises nitrogen and at least one hydrocarbon.

Abstract: A system for treating metallic articles in an atmospheric furnace while injecting at least one fluid material within the furnace and/or in a catalyst bed connected to the furnace.

Abstract: A carbonitriding method that can improve the nitrogen permeating rate to render the carbonitriding process effective is directed to carbonitriding a workpiece formed of steel that contains at least 0.8 mass % of carbon by heating in an atmosphere including ammonia, carbon monoxide, carbon dioxide and hydrogen. The method includes an atmosphere control step, and a heating pattern control step. The atmosphere control step includes an undecomposed NH3 partial pressure control step, a CO/CO2 partial pressure control step, and an H2 partial pressure control step. The undecomposed NH3 partial pressure control step, the CO/CO2 partial pressure control step and the H2 partial pressure control step are carried out such that the partial pressure of hydrogen in the heat treatment furnace is at least 0.1 atmospheric pressure and not more than 0.3 atmospheric pressure, and ? defined by the following equation (1) is at least 2.0 and not more than 6.0, in the atmosphere control step.

Abstract: A method and measurement system for the control of an active charge surface in a low pressure carburizing process can avoid formation of by-products and achieve regular carburized layers. This can be achieved through sampling of outlet gas at a specified time and comparison with experimentally set model characteristics.

Abstract: The invention relates to a process for the low-pressure carburisation of metal workpieces in an evacuable furnace, in which acetylene is added to the furnace atmosphere as the carburisation gas, wherein the partial pressure of the acetylene is varied intermittently and wherein the partial pressure of the acetylene in the furnace atmosphere is kept below 10 mbar. In order to specify a process for the low-pressure carburisation of metal workpieces that leads to an improvement, particularly with regard to the carburisation result, the invention proposes the use of a pot furnace as the furnace.

Abstract: A carbonitriding method that can improve the nitrogen permeating rate to render the carbonitriding process effective includes an atmosphere control step (50), and a heating pattern control step (60). The atmosphere control step (50) includes an undecomposed NH3 partial pressure control step (51), and a CO/CO2 partial pressure control step (53). The undecomposed NH3 partial pressure control step (51) and the CO/CO2 partial pressure control step (53) are carried out in the atmosphere control step (50) such that ac* defined by the following equation (1) is at least 0.88 and not more than 1.27, and ? defined by equation (2) is at least 0.012 and not more than 0.

Abstract: A system for treating metallic articles in an atmospheric furnace while injecting at least one fluid material within the furnace and/or in a catalyst bed connected to the furnace.

Abstract: A method and measurement system for the control of an active charge surface in a low pressure carburizing process can avoid formation of by-products and achieve regular carburized layers. This can be achieved through sampling of outlet gas at a specified time and comparison with experimentally set model characteristics.

Abstract: This invention is directed to a process and apparatus for producing high productivity carburizing. A process is introduced that uses a gas mixture made up of CO, H2, CO2, H2O, CH4 and N2, such that the product of the % CO and % H2 is greater than about 1600; the ratio of CO/CO2 is greater than 10; and the ratio of H2/H2O is greater than about 10. The gas mixture is controlled for a short time. A reactor for generating a gas mixture for carburizing steel is also introduced. This reactor is composed of a cylindrically symmetric body; a first central tube containing electrical heating elements for gas flow; a second central tube concentrically disposed around the first central tube; and a plurality of catalyst beds disposed in an annular space in a segmented fashion around the second central tube.

Abstract: The invention relates to a method for controlling the decarburization of steel components in a furnace during heat treating processes. The concentration of CO2 and/or CO in the furnace is monitored in a first batch in order to determine periods of elevated CO2/CO concentrations, and inert gas is injected in subsequent batches during the previously determined periods of elevated CO2/CO concentrations.

Abstract: Systems and methods for monitoring a heat treating atmosphere derive from at least one sensor placed in situ in the atmosphere a process variable, which is indicative of the ratio of gaseous hydrogen H2(g) to water vapor H2O(g) in the atmosphere. The systems and methods use the process variable, e.g., to control the atmosphere, or to record, or display the process variable.

Abstract: An iron-containing workpiece is case hardened by low temperature carburization during which one or more process steps—including adjusting the carburization temperature, adjusting the concentration of carburization specie in the carburization gas and reactivating the surfaces to be carburized—is carried out to enhance the overall rate and uniformity of carburization with minimized soot generation, whereby carburization can be completed faster than possible in the past.

Abstract: There is provided an economical carburizing method and carburization apparatus capable of carrying out carburizing treatment with a quality as high as that in a normal case and a high reproducibility even if carburizing conditions differ from those in a normal case. A carburization apparatus for carrying out carburization in an atmosphere gas containing not more than 30% by volume of carbon monoxide under a pressure of 13 to 4,000 Pa has a carburizing chamber 3 for housing an object 4 to be treated; an oxygen sensor 20 for measuring an oxygen concentration in the atmosphere gas in the carburizing chamber 3 during carburization; and a mass flow controller 5 for adjusting a composition of the atmosphere gas in the carburizing chamber 3 according to a measurement result by the oxygen sensor 20.

Abstract: A controlled nitrogen diffusion process is employed on a steel coil spring of a suspension system. One known process is that known as the Nitreg® process. Ammonia is introduced into a furnace atmosphere and nitrogen diffuses into the coil spring, creating a hardened diffusion zone which resists fatigue and fractures. The Nitreg® nitrogen diffusion process is a computer controlled menu driven process which continually monitors the process parameters. By regulating the nitriding potential, the monitored process parameters are automatically adjusted to achieve optimal results. The nitriding potential is the tendency of nitrogen to be absorbed by steel and is expressed as the ratio of the partial pressure of ammonia to the partial pressure of hydrogen. Additionally, the depth of the white compound layer can be regulated or eliminated, reducing distortions.

Abstract: In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace. The quantity of a residual CH.sub.4, a partial pressure of the oxidization gas and a partial pressure of CO are measured. The quantity of each gas to be supplied into the furnace is controlled according to either one of the values of the partial pressures.

Abstract: In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace, and the supply of the hydrocarbon series gas is stopped either when the quantity of a residual CH.sub.4 in the furnace is changed to increasing from decreasing, or when a partial pressure of oxygen in the furnace reaches a predetermined value.

Abstract: The invention relates to a power roller used for a toroidal-type continuously variable transmission. This power roller has on its first side a groove for receiving a bearing, and the surface of the groove (bearing surface) has a carbon concentration which is not lower than that of the back surface of a second side opposed to the first side. The power roller has a hardened outer layer having first and second portions which are respectively defined by the bearing surface and the back surface. The first portion of the hardened outer layer has an effective depth which is not shallower than that of the second portion thereof. The power roller is prepared by the sequential steps of surface-hardening, quenching, and grinding. The surface-hardening process is one of carburizing and carbonitriding.

Abstract: A coil spring made of an oil-tempered steel wire with internal hardness of more than Hv 550 in cross-section, the surface hardness of the oil-tempered steel wire being determined in an extent between Hv 420 in a minimum value and hardness defined by subtraction of Hv 50 from the internal hardness in a maximum value.

Abstract: In the continuous carburization furnace in which the temperature of the heaters can be controlled individually at every carburization processing position; carburization reference data at each carburization processing position is read; a temperature and carbon potential at each position at least during carburization and diffusion processes is detected; a carburized quantity of the processed member at each position is calculated with reference to the detected temperature and carbon potential; a carburization history is calculated by integrating the carburized quantity at each position of the carburization processed member, and a carburizing condition at a next carburization processing position is determined depending on a difference between the carburization history at the time of terminating the carburization process at each position of the carburization processed member and the carburization reference data at each position.