process for producing austenitic iron-carbon-manganese steel sheet with excellent resistance to delayed fractures, and the sheet thus produced

摘要

PROCESS FOR PRODUCING AUSTENIC IRON-MANGANESE STEEL PLATE WITH EXCELLENT RESISTANCE TO DELAYED FRACTURES, AND THE PLATE SO PRODUCED. The present invention relates to an excellent austenitic steel plate in delayed fracture resistance, the composition of said steel comprising by weight: 0.35% 243 C 243 1.05%, 15% 243 Mn 243 26%, Si 243%, Al 243 0.050%, S 243 0.030%, P 243 0.1%, at least one metal element X Vanadium, titanium, niobium, molybdenum, chromium: 0.050% 243 V 243 0.50%, 0.040% Ti 243 0.050%, 0.070% 243 Nb 243 0.50%, 0 , 14% 243 Mo 243 2%, 0070% 243 Cr 243 2% and optionally one or more elements chosen from: 0.0005% 243 B 243 0.010%, Ni 243 2%, Cu 243 5%, the remainder being iron and the inevitable manufacturing inherent impurities, including hydrogen, the amount Xp of said at least one metal element in the form of carbides, nitrides or carbonitrides being, by weight: 0.030% Vp 0.40%, 0.030% Tip 0.50%, 0.040% Nbp 0.40%, 0.14% Mop 0.44%, 0.070% Crp 0.6%, the hydrogen content Hmax desig The maximum hydrogen content that can be measured from a series of at least five specimens and the quantity Xp by weight, such as 1000 Hmax. Xp 243 3.3.