HIGH-STRENGTH STEEL WITH EXCELLENT UNSUSCEPTIBILITY TO HYDROGEN EMBRITTLEMENT

摘要

A high-strength steel excellent in hydrogen embrittlement resistance is provided. The high-strength steel of the present invention excellent in hydrogen embrittlement resistance has a tensile strength of 1800 N/mm² or above, contains 0.3 to 0.7% (percent by mass) C, 0.95 to 5.0% Cr, not higher than 0.6% and higher than 0% Mn, and 0.7 to 2.5% Si, and contains at least one of Mg, Ca, Sr, Ba, Li, Na and K so as to meet the following conditions:(1) the upper limits of the Mg, the Ca, the Sr, the Ba, the Li, the Na and the K content are 0.05%, and(2) the Mg, the Ca, the Sr, the Ba, the Li, the Na and the K content meet Expression (1):; $$ \begin{array}{cc}\mathrm{Cr}+\frac{\mathrm{Mn}}{4}\le 1000\times \left[\mathrm{Ca}+\frac{\mathrm{Mg}+\mathrm{Sr}+\mathrm{Ba}}{2}+\frac{\mathrm{Li}+\mathrm{Na}+K}{8}\right]& \left(1\right)\end{array}$$