Crack-resistant steel

Abstract

The present invention aims to provide a steel that can further reduce the deformation resistance and the probability of fracture when compressive stress is applied during cold working, and / or to provide a low-cost steel that can suppress fracture, has low deformation resistance and excellent workability, and can omit the spheroidizing annealing treatment before cold forging; to achieve the above objectives, a steel is provided for cold forging of steel for mechanical structures, wherein the ratio of the change in compressive stress ΔP (MPa) to the amount of compressive deformation ΔL (mm) when the steel is cold-compressed from a compression ratio X% to a compression ratio Y% is ΔP / ΔL or less.

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