Disclosed herein are a platinum catalyst and a process for preparing the same. The catalyst comprises carbon supports and the carbides of (i) platinum and of (ii) one or more metals selected from the group consisting of nickel, cobalt, chromium and iron, and if necessary of (iii) manganese, supported on the carbon supports. The catalyst possesses superior catalyst performance because the catalyst metals are firmly fixed to the carbon supports by means of the carburizing. The process for preparin...

A case carburizable stainless steel alloy intended to be used at operating temperatures up to 700.degree. F. The alloy is able to achieve and maintain a high surface hardness when carburized and heat treated and combines high fracture toughness, hot hardness, metal-to-metal wear resistance and corrosion resistance while retaining core ductility and strength. The alloy consists essentially of (in weight percent) 0.1 to 0.25% carbon, 0 to 1% silicon, 0 to 1% manganese, 13 to 19% chromium, 1.75 to ...

A powder metallurgical process for producing dense low-alloy ferrous parts having selected carburized surface portions in which a metal powder of the desired composition is briquetted into a shape-retaining preform, the preform is masked, sintered, carburized whereafter the mask is removed and the resultant preform is forged to a desired final shape. The forged part is then quenched immediately following the forge operation for hardness or if desired it can be further heat treated in another man...

Steel is carburized at a temperature within the austenitic range and in an atmosphere which comprises nitrogen, hydrogen and carbon monoxide, by lowering the hydrogen concentration in the treatment atmosphere prior to cooling steel in oil, salt or water, so as to reduce the hydrogen concentration in the carburization layer of the steel, by outward diffusion of hydrogen from the carburization layer.

The invention relates to a method for welding shaped bodies of carburized heat-resistant austenitic steel. The inventive method is characterized in that carburized steel parts to be welded are preheated to temperatures of 700 to 900 degrees Celsius before welding, and the preheated carburized steel parts are welded with current intensities of 50 to 200 A.

A heat resistant carburized rolling bearing component is formed of a steel material at least containing, as alloy elements in a matrix, by mass %, at least 0.1% and at most 0.4% of C, at least 0.3% and at most 3.0% of Si, at least 0.2% and at most 2.0% of Mn, at most 0.03% of P, at most 0.03% of S, at least 0.3% and less tan 2.5% of Cr, at least 0.1% and less than 2.0% of Ni, at most 0.050% of Al, at most 0.003% of Ti, at most 0.0015% of O and at most 0.025% of N, and a remaining part of Fe and ...

Disclosed herein is an improved method of finishing a steel article having a carburized and boronized case. The article is carburized to a selected depth then finished to a smoothness which is smoother than the desired final finish. The article is then boronized, hardened and tempered. Further finishing is unnecessary.

A method for high concentration carburizing and quenching of steel is provided which is carried out by a treatment process including the steps of carbonitriding the steel at temperatures of from about 800 to about 880.degree. C., and subsequently quenching the steel at a temperature higher than the carbonitriding temperature. In the carbonitriding step, the steel is treated with carbon concentrations in a carburizing atmosphere taken as about 0.7 to about 1.2% and with 3 to 8% of ammonia gas (NH...

Steel compositions and processes are described that provide optimum resistance to austenite grain coarsening in cold-formed and carburized components for automotive and machine structural applications. The steel compositions include, in weight percent, 0.1-0.3% C 150-220 ppm N and a grain refining addition selected from the group consisting of Al, V plus Al and Nb plus Al, the balance comprising iron and other alloying elements typically found in carburizing grades of steel. The steels are proce...

A case hardening steel having good-grain coarsening prevention properties during carburization. The steel comprises, by weight, 0.1 to 0.4%. C, 0.02 to 1.3% Si, 0.3 to 1.8% Mn, 0.001 to 0.15% S, 0.015 to 0.04% Al, 0.005 to 0.04% Nb, 0.006 to 0.020% N, one, two or more selected from 0.4 to 1.8% Cr, 0.02 to 1.0% Mo, 0.1 to 3.5% Ni, 0.03 to 0.5% V, and in which P is limited to not more than 0.025%, Ti is limited to not more than 0.010%, and O is limited to not more than 0.0025%, with the balance be...