Alloy for carburized bearing members intended to be used at operating temperatures up to 1000.degree.F, characterized in having the ability to achieve and retain high surface hardness after carburization coupled with good hot-workability which enables billets formed from the alloy to be pierced in a seamless tube-forming operation. Also described is the method for heat treating such an alloy to achieve the desired surface hardness, on the order of Rockwell C58 and higher. The alloy contains, as ...

Disclosed herein is a cutter for a rock bit that has an interior bearing race area carburized by pack carburization methods to achieve a high carbon content for extreme hardness. The exterior of the cutter is carburized also, but to a lesser degree, to avoid brittleness in the tooth area. The differential carburizing is accomplished by gas carburizing the exterior while simultaneously pack carburizing the interior. Conventional heat treatment for hardening follows. This results in a cutter havin...

A process for forming a carburized steel article includes carburizing a steel material containing not more than 0.10% silicon and less than 1.1% chromium to form an austenitic surface matrix having a high density of carbides dispersed therein. After quenching, the carburized steel article is characterized by an outer surface having a high ratio of carbides and is substantially free of intergranular oxides. As a result of preventing undesirable surface oxide formations and simultaneously providin...

A ceramic-steel joined body includes a ceramic body of silicon nitride, zirconia, silicon carbide, boron nitride, and alumina. The joined body also includes a steel body which has its surface carburized so that the hardness of the surface is greater than the hardness of the inside of the steel body. The ceramic body and the steel body are thermally joined using a brazing material of Ag--Cu--Ti, Ag--Cu--In--Ti, Ag--Ti, Cu--Ti, Ag--Cu--Ni--Ti, Ag--Cu or Ag--Cu--In.

In the direct reduction of iron ore in a series of fluidized beds, for the production of carburized iron sponge briquettes for use in electric furnaces, carburization is carried out after the last fluidized bed, at a temperature of 600.degree. to 700.degree. C., by batching the reduced iron powder with a solid finely divided carbonaceous material and then briquetting the mixture, in an inert atmosphere.

The depth of a case on a specimen of case-carburized steel is measured by launching an acoustic wave along the surface of the specimen such that the wave passes through the case, and measuring the velocity of that wave within the specimen. From an existing correlation of velocity and case depth for the very same core steel as the specimen, one finds the case depth which corresponds to the measured velocity, and that is the case depth of the specimen.

A rotary output shaft for a vehicle starter motor having a planet gear speed reducing device is formed by forging a steel blank to form a product having a shape similar to the rotary output shaft but having slightly larger outer dimensions, by subjecting a planet gear carrier portion 7c of the forged entire product to copper plating to prevent carburization, by subjecting the product to a carburizing treatment, and by finishing the locally carburized portion of the product.

In order to keep down soot production and to enable every part of the workpiece, including deep concavities to be uniformly carburized by vacuum carburizing, and to enable decreases in the quantities of gas and heat employed, carburizing treatment is performed in the heating chamber 2 of a vacuum carburizing furnace 1 with workpieces M being heated while acetylene gas is supplied from a carburizing gas source C inside the heating chamber 2, and the inside of the heating chamber 2 being evacuated...

A carburizing method is described which is capable of dispersing cementite grains in the surface of steel uniformly and finely as not to affect fatigue strength and capable of fining the crystal grains of austenite. To prevent cementite precipitation during high temperature carburization at 980.degree. C. or more, steel contains Al in an amount in the range of 0.05.ltoreq.[Al wt %].ltoreq.2.0 and Cr in an amount in the range of 0.3.ltoreq.[Cr wt %].ltoreq.4.0, and the composition of the steel sa...

Silicon carbide films are grown by carburization of silicon to form insulative films. In one embodiment, the film is used to provide a gate insulator for a field effect transistor. The film is grown in a microwave-plasma-enhanced chemical vapor deposition (MPECVD) system. A silicon substrate is fast etched in dilute HF solution and rinsed. The substrate is then placed in a reactor chamber of the MPECVD system in hydrogen along with a carbon containing gas. The substrate is then inserted into a m...