Medium-/high-carbon steel sheet and method for manufacturing same

Abstract

The medium- / high-carbon steel sheet according to one aspect of the present invention is a steel sheet containing, in mass%, C: 0.10-1.50%, Si: 0.01-1.00%, Mn: 0.01-3.00 mass%, P: 0.0001-0.1000%, and S: 0.001-0.1000%, with the remainder having components comprising Fe and impurities, wherein the total volume fraction of martensite, bainite, pearlite, and residual austenite is 5% or less, the remainder being a composition of ferrite and carbide; the spheroidizing ratio of the carbide particles is 70 to 99%, inclusive; and the number of carbide particles that include crystal interface misorientation of 5 degrees or greater, expressed as a proportion of the carbide particles, is 20% or less with respect to the total number of carbide particles.

Description

technical field [0001] The present invention relates to a medium / high carbon steel sheet having excellent deep drawing in forming at a high strain rate and a method of manufacturing the same. [0002] this application claims priority based on Japanese Patent Application No. 2014-045689 for which it applied to Japan on March 7, 2014, and uses the content here. Background technique [0003] Medium / high carbon steel sheets are used as raw materials for driving system components such as chains, gears, and clutches of automobiles, saws, and knives. A raw material formed into a predetermined shape from a strip of medium / high carbon steel or a steel plate cut from a strip is formed into a part shape through plastic processing such as deep drawing, hole expansion, thickening, and thinning. In cold forging in which each process is performed individually or several of them are performed simultaneously, the raw material is partially formed at a high strain rate of about 10 / sec, and th...

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Problems solved by technology

[0011] However, in any of these patent documents, for suppressing the cracks of the cementite itself inside the steel material generated at the time of forming at a high strain rate, and the growth / connection of voids caused by the occurrence of cracks The understanding and technology of the reduction of deep drawing are not disclosed in any

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