sheet (embodiments) and method of producing austenitic iron/carbon/manganese steel sheet (embodiments)

摘要

The invention relates to a hot rolled sheet which is made from austenitic iron/carbon/manganese steel and which has a strength of greater than 1200 MPa, of which the product P (resistance (MPa) x elongation at rupture (%)) is greater than 65000 MPa %. The nominal chemical composition of the inventive sheet comprises the following concentrations expressed as weight: 0.85% C 1.05%; 16% Mn 19%; Si 2%; Al 0.050%; S 0.030%; P 0.050%; N 0.1%, and, optionally, one or more elements selected from among Cr 1%; Mo 1.50%; Ni 1%; Cu 5%; Ti 0.50%; Nb 0.50%; V 0.50%, the rest of the composition comprising iron and inevitable impurities resulting from production. According to the invention, the recrystallised surface fraction of the steel is equal to 100 %, the surface fraction of precipitated carbides of said steel is equal to 0 % and the average grain size thereof is less than or equal to 10 micrometers.