Abstract: A super carburized, low-distortion quenched member with higher performance and minimized heat-treatment distortion is provided. A process for the production thereof includes a primary treatment and a secondary treatment. The primary treatment includes heating a steel member for a machine structure to a temperature within an austenite region by vacuum carburizing (low-pressure carburizing) to have carbon dissolved at least at a eutectoid carbon concentration of a surface layer portion of the member and then quenching the member to have at least one of ultrafine carbide and nuclei of the carbide formed in the surface layer portion of the member. The secondary treatment includes subsequently heating and soaking the member to a temperature within the austenite region and then conducting rapid quenching to have ultrafine carbide precipitated in an outermost surface layer portion.

Abstract: Self-adhesive carbonaceous grains for use in the production of high density carbon artifacts and high performance carbon-carbon composites are made by processes such as oxidation and heat treatment of specific mesophase pitches. The present carbonaceous grains exhibit excellent binding properties, shape stability when molded, and high density with higher carbonization yield, providing very high strength artifacts when their properties fall within the specific range of properties defined by their H/C and O/C values. High density carbon artifacts can be easily obtained by molding the grains and carbonizing or graphitizing the same.

Abstract: A carbon steel useful for machine structural use having improved cold forgability and induction hardenability comprises particular amounts of C, Si, Mn, Cr, S, P, O, N or further Mo and the balance being substantially Fe.

Abstract: A connecting rod having a pair of spaced apart flanges parallel to a plane defined by a crankshaft axis and a piston pin axis. A web connects the flanges to form a rod portion having an I-shaped cross section. The inner surfaces of the flanges include a lateral rounded projection adjacent to the flange edges to improve bending and stress characteristics.

Abstract: A DOHC engine of the V-type has two cylinder heads each detachably secured to a cylinder block. A crank shaft on the block drives two intermediate shafts, one on each cylinder head, by means of an endless flexible element. An additional flexible endless element is provided in each cylinder head to drive two cam shafts from the intermediate shaft on that cylinder head. Each endless flexible element together with its toothed pulleys or sprockets and its timing belt or chain is described as a wrap-around transmission.