STEEL FOR MECHANICAL PARTS, METHOD FOR PRODUCING MECHANICAL PARTS FROM SAID STEEL AND THE THUS OBTAINABLE MECHANICAL PARTS

摘要

The inventive steel for mechanical parts is characterised by the composition thereof expressed in the following percentages by weight: 0.19 % = C = 0.25 %; 1.1 % = Mn = 1.5 %; 0.8 % = Si = 1.,2 %; 0.01 % = S = 0.09 %; traces = P = 0.025 %; traces = Ni_{= 0.25 %; 1 % = Cr = 1.4 %; 0.10 % = Mo = 0,25 %; traces = Cu= 0.30 %; 0.01 % = Al = 0.045 %; 0.010 % = Nb = 0.045 %; 0.0130 % = N = 0.0300 %; optionally traces = Bi = 0.10 % and/or traces = Pb = 0.12 % and/or traces = Te = 0.015 % and/or traces = Se = 0.030 % and/or traces = Ca= 0.0050 %. The rest being iron and impurities resulting from preparation, a chemical composition being adjusted in such a way that mean values J3m, J11m, J15m et J25m of five Jominy tests are such as a = | J11m - J3m x 14/22 - J25mx 8/22 |= 2.5 HRC; and ß = J3m - J15m = 9 HRC. A method for producing a mechanical part from said steel and the thus obtainable mechanical part are also disclosed.}