Hardened martensitic steel with low cobalt content, one piece manufacturing process from this steel and piece thus obtained

摘要

Steel characterized in that its composition is, in weight percentages: - C = 0.18-0.30% - Co = 1.5-4% - Cr = 2-5% - Al = 1-2% - Mo + W / 2 = 1-4% - V = traces - 0.3% - Nb = traces - 0.1% - B = traces - 30 ppm - Ni = 11-16% with Ni = 7 + 3.5 Al - Si = traces - 1.0% - Mn = traces - 2.0% - Ca = traces - 20 ppm - Rare earths = traces - 100 ppm - if N = 10 ppm, Ti + Zr / 2 = traces - 100 ppm with Ti + Zr / 2 = 10 N - if 10 ppm N = 20 ppm, Ti + Zr / 2 = traces - 150 ppm - O = traces - 50 ppm - N = traces - 20 ppm - S = traces - 20 ppm - Cu = traces - 1% - P = traces - 200 ppm being the rest iron and inevitable impurities resulting from the elaboration.