摘要:
By pouri-ng, by means of pressure, melted liquid of magnesium or magnesium alloy into a hollow portion which is formed using a casting mold, a valve body where a channel groove for hydraulic oil for use in a speed change operation of the automatic transmission is formed. In the above, the channel grove for the hydraulic oil is formed due to a convex portion which is formed on the mold so as to project into the hollow portion. As the magnesium has small heat capacity, variation of the temperature of the mold during the cooling and heating cycle can be suppressed. Moreover, as the magnesium melted liquid has no reactivity with respect to the casting mold, the convex portion is not deteriorated. This allows employment of a mold having a thinner convex portion formed thereon, and therefore formation of a valve body having a narrower channel groove.
摘要:
A method for manufacturing a powder for a magnetic core including at least a process of performing a siliconizing treatment on a surface of an iron powder (Ha) containing elemental carbon. In the process of siliconizing treatment, a powder (21a) containing at least a silicon dioxide is brought into contact with the surface of the iron powder (Ha), elemental silicon is detached from the silicon dioxide by heating the powder (21a) of silicon dioxide, and the siliconizing treatment is performed by causing the detached elemental silicon to permeate and diffuse into a surface layer of the iron powder (21a). The invention provides a method for manufacturing a powder for a magnetic core, by which loss reduction is achieved.
摘要:
A forged component having a chemical composition including, by mass%, C: 0.30 to 0.45%, Si: 0.05 to 0.35%, Mn: 0.50 to 0.90%, P: 0.030 to 0.070%, S: 0.040 to 0.070%, Cr: 0.01 to 0.50%, Al: 0.001 to 0.050%, V: 0.25 to 0.35%, Ca: 0 to 0.0100%, N: 0.0150% or less, and the balance being Fe and unavoidable impurities, and satisfying formula 1. Metal structure is a ferrite pearlite structure, and a ferrite area ratio is 30% or more. Vickers hardness is in the range of 320 to 380 HV. 0.2% yield strength is 800 MPa or more. A Charpy V-notch impact value is in the range of 7 to 15 J/cm 2 .
摘要:
A valve body where flow path grooves for hydraulic oil used for speed change operation of an automatic speed changer are formed between partition walls by forcing molten magnesium or magnesium alloy into a hollow section formed by a mold. In this process, the flow path grooves are formed by projections provided on the mold and projecting in the hollow section. Since the heat capacity of magnesium is small, the temperature variation width of the mold in a thermal cycle can be restricted to be small, and further, magnesium has no reactivity with the mold. As a consequence, the thickness of the projections on the mold can be reduced without causing degrading of the projections.