Surface-hardened steel with excellent crack resistance

Abstract

The object of this invention is to provide a surface-hardened steel that provides excellent cold-rolled workability, particularly crack resistance, while ensuring hardenability. This surface-hardened steel, by weight percent, comprises the following: C: 0.15% to 0.30%, Si: 0.05% to 1.00%, Mn: 0.10% to less than 0.50%, Cr: 1.3% to 2.5%, Ni: 0% to 0.5%, Mo: 0% to 0.5%. The following components are present: % to 0.5%, Al: 0% to 0.050%, Ti: 0% to 0.20%, Nb: 0% to 0.10%, B: 0% to 0.0050%, N: 0% to 0.0300%, and the remainder: Fe and unavoidable impurities; among the unavoidable impurities, P is 0.030% or less and S is 0.025% or less, and the grade of the granular iron strip with a cross-section parallel to the hot rolling direction is 1 to 3.

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