Kobe Steel, Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Shuhei Kitamura

Nao Yoshihara

Tomonobu Ishida

Provided are: a steel wire rod material for a high-strength spring, which does not undergo the increase in deformation resistance arising from the increase in hardness and can exhibit good wire-drawing processability and the like even when a heat treatment, which deteriorates productivity, is eliminated or a simplified and rapid heat treatment is employed instead; a useful method for producing the steel wire rod material for a high-strength spring; a high-strength spring produced using the steel wire rod material for a high-strength spring as a material; and others. This steel wire rod material for a high-strength spring is a steel wire rod material that has been hot-rolled already, and has a texture having a specified chemical composition and mainly composed of pearlite, wherein the average value (Pave) of the pearlite nodule size numbers and the standard deviation (P&#x3c3;) of the pearlite nodule size numbers fulfill the following formulae (1) and (2), respectively:9.5&#x2266;ave&#x2266;12.0;&#x2003;&#x2003;(1)and0.2&#x2266;&#x3c3;&#x2266;0.7&#x2003;&#x2003;(2).

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Kobe, Japan

Shuhei Kitamura