alloy staalprodukt with high haerdeevne in relation to its legeringsindhold and a procedure for the manufacture thereof

摘要

The invention refers to a method for manufacturing a steel product having a very high hardenability in relation to its alloying content. The method is characterized by melting at least the bulk of a steel composition containing a majority of alloy ingredients to produce a steel me superheating said steel melt at a temperature of at least 1625 DEG C and maintaining said melt at said temperature for at least two minutes to form a supertreated me prior to said superheating adding to said steel composition at least one micro-alloying ingredient selected from the group consisting of aluminum, titanium, and zirconium; teeming and casting said superheated melt to form cast products; and hot-working said cast products to form said steel product. The invention also concerns a steel product in the form of a block, bar, plate, or forged shape or casting made according to the above method from a steel having the following composition in weight percent: Carbon 0.12 to 0.75, Manganese 0.3 to 1.5, Silicon from traces up to 1.0, Chromium from traces up to 5.0, Nickel from traces up to 2.0, Molybdenum 0.05 to 3.0, Vanadium 0.05 to 1.5, Niobium from traces up to 0.3, Phosphorus 0.03 max, Sulphur from traces up to 0.05, Aluminum 0.02 to 0.16 or, Titanium 0.015 to 0.08 or, Zirconium 0.015 to 0.08 or, at least two of Aluminum, Titanium and Zirconium, wherein the total amount of A1 + 2(Ti + Zr) is about 0.02 to about 0.16.