STEEL WIRE ROD FOR HIGH-STRENGTH SPRING WITH EXCELLENT HYDROGEN EMBRITTLEMENT RESISTANCE AND MANUFACTURING PROCESS THEREFOR AND HIGH-STRENGTH SPRING.

摘要

A steel wire rod for a high-strength spring is provided. This steel wire rod comprises at least 80% by area of tempered martensite and exhibits a tensile strength of 1900MPa or more, wherein the steel wire rod satisfies a prescribed chemical composition and a relationship (1) between the contents of C and Si and exhibits a prior austenite grain size number of 10 or more and a hydrogen storage of 14.0 ppm or more. Thus, the steel wire rod can ensure hydrogen embrittlement resistance even in a case where the amount of an alloying element added is reduced. 0.73% ≤ [C]+[Si]/8 ≤ 0.90% ··· (1) [wherein [C] and [Si] represent the contents (mass%) of C and Si respectively].