Abstract: A high copper carbon alloy steel sheet made by preparing a molten melt producing an as-cast carbon alloy steel sheet including, (i) by weight, between 0.15 and 0.50% carbon, less than 1.0% chromium, between 3.0 and 9.0% manganese, between 0.2 and 3.5% silicon, more than 0.5% copper, less than 0.01% aluminum, a total oxygen level of at least 50 or 100 ppm; (ii) nickel in levels below 0.5%; (iii) the remainder iron and impurities resulting from melting; solidifying and cooling the molten melt into a sheet less than 10 mm in thickness in a non-oxidizing atmosphere to below 1080° C. at a cooling rate between 1000 and 2000° C./s, hot rolling the as-cast sheet to between 10 and 50% reduction to form a sheet with microstructure providing a tensile strength of at least 900 MPa and an elongation of at least 15%.