FIELD: metallurgy.
SUBSTANCE: steel contains the following, wt %: carbon 0.05 - ≤ 1.0, aluminium 0.0 - ≤ 11.0, silicon 0.0 - ≤ 6.0, manganese 9.0 - ≤ 25.0, hydrogen < 20 ppm, iron and inevitable impurities are the rest. Total content of aluminium and silicon is more than 0.05. Paired values of carbon and manganese 0.7C/15Mn, 2.5% Al, 2.5% Si and 0.4C/18Mn, 2.5% Al, 2.5% Si are located in C-Mn coordinate system approximately on one straight connecting line located from paired values of carbon and manganese, which are in balanced condition between γ phase of austenite and α' phase of martensite. Scatter band around the connecting line of optimum paired values of carbon and manganese is as follows: for carbon content ± 0.15%, and for manganese content ± 2.5%.
EFFECT: steel has no delayed hydrogen embrittlement effect at maintaining high mechanical properties.
3 cl, 1 dwg
