Process for manufacturing iron-carbon-manganese austenitic steel sheet with excellent resistance to delayed cracking, and sheet thus produced

摘要

An austenitic steel sheet excellent in resistance to delayed cracking, the compositionof said steel comprising, in weight: 0,35% C 1,05%,15% Mn 26%,Si 3%, Al 0,050%, S 0,030%, P 0,080%, N 0,1 %, at least onemetallic element X chosen among vanadium, titanium, niobium, molybdenum, chromium:0,050%V 0,50%, 0,040% ≤Ti 0,50%, 0,070% Nb 0,50%, 0,14%Mo 2%, 0,070% Cr 2 % and optionally, one or several elements chosenamong 0,0005% B 0,010%, Ni 2%, Cu 5%,the remainder being ironand unavoidable impurities inherent to fabrication, including hydrogen, thequantity Xp of said at least one metallic element under the form of carbides, nitridesor carbonitrides being, in weight : 0,030% VP 0,40%, 0,030%Tip 0,50%, 0,040% Nbp 0,40%, 0,14%Mop 0,44%, 0,070% Crp0,6%, the hydrogen content Hmax designating the maximal hydrogen content thatcan be measured from a series of at least five specimens, and the quantity Xp, inweight, being such that (I) 3,3.