Abstract: The invention makes a steel available, which, in the case of edge-layer hardening without subsequent relaxation annealing, not only has the potential for developing a hardened edge layer having a great surface hardness, in particular a surface hardness that amounts to more than 820 HV1, but rather also possesses a ductile, fine-grained grain structure and, at the same time, can be easily welded. For this purpose, a steel according to the invention consists of (in weight %) C: 0.10-0.19%, Si: ?0.15%, Mn: ?1.0%, P: ?0.015%, S: ?0.015%, Cr: 0.2-1.0%, Ni: 0.7-2.0%, Mo: 0.5-1.0%, N: ?0.015%, Al: 0.010-0.060%, Cu: ?0.20%, B: ?0.005%, as well as optionally, in each instance, one or more elements from the group “W, Ti, Nb, V, Ta” in content values in accordance with the following stipulations: W: 0.15-0.65%, Ti: 0.01-0.04%, Nb: 0.015-0.05%, Ta: 0.01-0.04%, V: 0.04-0.12%, and, as the remainder, of iron and unavoidable contaminants.

Abstract: The invention relates to a micro-alloyed pearlitic steels contain 0.20 to 0.50% C, 0.40 to 1.0% Si, 0,80 to 1,80% Mn, 0.008 to 0.2% S, 0 to 0.7% Cr, 0 to 0.1% Al, 0 to 0.04% N, 0.01 to 0.05% Ti, remainder iron and impurities resulting from the melting process, with mixed sulphides (manganese, titanium carbonitrides, and the like) precipitated on the grain boundaries. The steel may preferably contain an additional content of up to 0.20% V and/or up to 0.10% Nb.

Abstract: Parts made of a heat-treated alloy steel having a minimum tensile strength of 700 N/mm.sup.2 and a notch toughness of at least 55 joules, wherein the alloy steel is a Mn/Cr/Nb alloy steel of lower alloy content than has hitherto been used to provide the desired strength/toughness properties.