Part comprising an optimized steel material and its manufacturing process

A part, comprising:

• a steel material comprising grains comprising a matrix into which precipitates are incorporated,
• wherein the steel material comprises, in weight percentage
• 16% to 20% chrome,
• 8% to 14% nickel,
• 0.001% to 0.030% carbon,
• 0.001% to 0.050% oxygen,
• 0% to 2% manganese,
• 0% to 3% molybdenum,
• 0% to 1% silicon, and
• iron;
• and
• wherein the precipitates comprise a metallic element comprising yttrium, titanium, iron, chromium, tungsten, silicon, zirconium, thorium, magnesium, manganese, aluminum, hafnium, and/or molybdenum,
• wherein the steel material has a microstructure of equiaxed grains having an average grain size average size in a range of from 10 μm to 50 μm in the largest dimension Dmax and/or a smallest dimension D,
• wherein the grains of the steel material are equiaxed in a plane which is parallel to superimposed layers resulting from an additive manufacturing process,
• wherein the grains of the steel material are equiaxed in a plane which is perpendicular to the superimposed layers resulting from the additive manufacturing process,
• wherein an average density with which the precipitates are distributed in the matrix of the steel material is in a range of from 2 to 100 precipitates/μm3, and
• wherein the part has a cellular structure or a honeycomb structure.