High carbon steel plate and manufacturing method therefor

Abstract

A high carbon steel plate: has a chemical composition represented, in mass%, by C: 0.30%-0.70%, B: 0.0004%-0.0035%, etc.; has a structure represented by cementite spheroidization rate: 80% or higher and mean cementite particle diameter: 0.3-2.2 [mu]m; and has a ferrite microfriction coefficient at the surface of less than 0.5.

Description

technical field [0001] The present invention relates to a high-carbon steel sheet with improved formability and a method for producing the same. Background technique [0002] High-carbon steel sheets are used in various steel products such as chains, gears, and clutches of automobiles, saws, and knives. When manufacturing these steel products, forming and heat treatment of high-carbon steel sheets are performed. As forming, punching processing, stretching processing, compression processing, shearing processing, etc. are performed, and as heat treatment, quenching, tempering, carburizing, nitriding, salt bath nitriding, etc. are performed. Since the strength level of the high-carbon steel plate is higher than that of the mild steel plate, the dies used for the forming of the high-carbon steel plate are more prone to wear than those used for the forming of the mild steel plate. In addition, high-carbon steel sheets are more likely to crack during forming than mild steel shee...

AI Technical Summary

Problems solved by technology

[0004] However, these conventional techniques are accompanied by a significant cost increase and are not preferred

[0005] Patent Document 6 describes a carbon steel sheet aimed at improving punchability, and Patent Document 7 describes a high-carbon steel sheet aimed at improving formability, but neither of them can obtain sufficient formability.

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