Abstract: Provided is spring steel for suspension suppressing or not requiring addition of expensive alloy elements, having a large tensile strength, and excellent in cold formability and delay fracture resistance, wherein at a cross-section parallel to a rolling direction, 90% or more of the metal microstructures by area fraction is tempered martensite, and at a cross-section parallel to the rolling direction, in a range of 10% of diameter or thickness from the surface, a ratio of a length in a long axis direction of prior austenite grains and a length in a direction perpendicular to the long axis direction of the prior austenite grains is 1.5 or more and a ratio of <011> fraction/<111> fraction of martensite texture as seen from the rolling direction is 3.0 or more.

Abstract: According to one aspect of the present invention, there is provided a process of fabricating a steel material by performing a heat treatment to a steel material having high strength, in order to reduce hardness at one part of the steel material to less than hardness at other parts of the steel material, wherein the heat treatment comprises a heating step in which a portion having a certain depth from a surface of the steel material is rapidly heated by induction heating or direct energization heating, and a cooling step in which the steel material, which has been subject to the heating step, is rapidly cooled a predetermined time after the heating step, and a heating temperature in the heating step is Ac1 transforming point or more.