Steel material, for which the grains of which it is composed comprise a matrix in which precipitates are incorporated, in which material: i) the material comprises, as percentage by weight, the following elements: - from 16% to 20% of chromium, - from 8% to 14% of nickel, - from 0.001% to 0.030% of carbon, - from 0.001% to 0.050% of oxygen, - from 0% to 2% of manganese, - from 0% to 3% of molybdenum, - from 0% to 1% of silicon, - from 0% to 0.11% of nitrogen, - from 0% to 0.045% of phosphorus, - from 0% to 0.05% of sulfur, - from 0% to 0.0300% of aluminium, - from 0% to 2% of manganese, - from 0% to 3% of molybdenum, - from 0% to 0.003% of vanadium, - from 0% to 0.02% of cobalt, - from 0% to 0.02% of titanium, - from 0% to 0.02% of copper, - the balance of these elements consisting of iron; ii) the precipitates comprise at least one metal element chosen from a metal element M, a metal element M', a metal element M" or their mixtures; the metal elements being chosen, independently of one another, from yttrium, titanium, iron, chromium, tungsten, silicon, zirconium, thorium, magnesium, manganese, aluminium, hafnium, molybdenum or their mixtures; the mean density with which the precipitates are distributed in the matrix being of between 2 precipitates/μm 3 and 100 precipitates/μm 3, said mean density being determined by counting via imaging by Scanning Electron Microscopy or by Transmission Electron Microscopy, the microstructure of the steel being such that the grains are equiaxial and the mean size of the grains, measured according to Standard ASTM E112-10, being such that the mean of their greatest dimension "Dmax" and/or the mean of their smallest dimension "Dmin" is of between 10 μm and 50 pm. i) the material comprises, as percentage by weight, the following elements: - from 16% to 20% of chromium, - from 8% to 14% of nickel, - from 0.001% to 0.030% of carbon, - from 0.001% to 0.050% of oxygen, - from 0% to 2% of manganese, - from 0% to 3% of molybdenum, - from 0% to 1% of silicon, - from 0% to 0.11% of nitrogen, - from 0% to 0.045% of phosphorus, - from 0% to 0.05% of sulfur, - from 0% to 0.0300% of aluminium, - from 0% to 2% of manganese, - from 0% to 3% of molybdenum, - from 0% to 0.003% of vanadium, - from 0% to 0.02% of cobalt, - from 0% to 0.02% of titanium, - from 0% to 0.02% of copper, - the balance of these elements consisting of iron; - from 16% to 20% of chromium, - from 8% to 14% of nickel, - from 0.001% to 0.030% of carbon, - from 0.001% to 0.050% of oxygen, - from 0% to 2% of manganese, - from 0% to 3% of molybdenum, - from 0% to 1% of silicon, - from 0% to 0.11% of nitrogen, - from 0% to 0.045% of phosphorus, - from 0% to 0.05% of sulfur, - from 0% to 0.0300% of aluminium, - from 0% to 2% of manganese, - from 0% to 3% of molybdenum, - from 0% to 0.003% of vanadium, - from 0% to 0.02% of cobalt, - from 0% to 0.02% of titanium, - from 0% to 0.02% of copper, - the balance of these elements consisting of iron; ii) the precipitates comprise at least one metal element chosen from a metal element M, a metal element M', a metal element M" or their mixtures; the metal elements being chosen, independently of one another, from yttrium, titanium, iron, chromium, tungsten, silicon, zirconium, thorium, magnesium, manganese, aluminium, hafnium, molybdenum or their mixtures; the mean density with which the precipitates are distributed in the matrix being of between 2 precipitates/μm 3 and 100 precipitates/μm 3, said mean density being determined by counting via imaging by Scanning Electron Microscopy or by Transmission Electron Microscopy, the microstructure of the steel being such that the grains are equiaxial and the mean size of the grains, measured according to Standard ASTM E112-10, being such that the mean of their greatest dimension "Dmax" and/or the mean of their smallest dimension "Dmin" is of between 10 μm and 50 pm.