Stainless steel powders for additive manufacturing
Exemplary alloys may be particularly suited for additive manufacturing applications, and may comprise iron and one or more of: chromium (Cr), nickel (Ni), carbon (C), and copper (Cu). Exemplary alloys may have a majority microstructure that is martensite.
1. An as-built alloy consisting of, by weight percentage:
15.0% to 15.75% chromium;
2.90% to 5.0% nickel;
0.05% to 0.08% carbon;
2.90% to 4.50% copper;
no more than 0.01% niobium;
no more than 0.02% nitrogen;
no more than 0.04% oxygen;
no more than 0.01% tantalum,
no more than 0.1% silicon,
no more than 0.5% manganese;
no more than 0.31% titanium;
the balance of weight percent comprising iron and incidental elements and impurities; and
the as-built alloy having a hardness from 36 HRC to 40 HRC and a total elongation of no less than 10% and no greater than 16% in response to additive manufacturing using a laser power of 195 W, a scan speed of 750 mm/s, a hatch spacing of 0.1 mm, and a layer thickness of 40 μm, and without aging or solution heat treating.
2. The as-built alloy according to claim 1 , wherein a ratio of nickel to copper is no less than 1.
3. The as-built alloy according to claim 1 , consisting of, by weight percentage, 15.0% to 15.5% chromium, 2.9% to 3.9% nickel; 0.06% to 0.07% carbon, 2.9% to 3.9% copper; 0.05% to 0.25% titanium; about 0.01% nitrogen and about 0.03% oxygen.
4. The as-built alloy according to claim 1 , consisting of, by weight percentage, 15.0% to 15.5% chromium, 4.0% to 5.0% nickel; 3.5% to 4.5% copper; and less than 0.01% titanium.
5. The as-built alloy according to claim 1 , wherein the as-built alloy has been subjected to an additive manufacturing process and without aging, has a fatigue strength of 475 MPa to 525 MPa.
6. An as-built alloy consisting of, by weight percentage:
15.0% to 15.75% chromium;
2.90% to 5.0% nickel;
0.05% to 0.08% carbon;
2.90% to 4.50% copper;
no more than 0.01% niobium;
no more than 0.02% nitrogen;
no more than 0.04% oxygen;
no more than 0.01% tantalum;
no more than 0.01% silicon;
no more than 0.25% titanium;
no more than 0.1% manganese;
the balance of weight percent comprising iron and incidental elements and impurities; and
the as-built alloy, when additively manufactured using a laser power of 195 W, a scan speed of 750 mm/s, a hatch spacing of 0.1 mm, and a layer thickness of 40 μm, and without aging or solution heat treating, having a hardness from 36 HRC to 40 HRC and a total elongation of no less than 10% and no greater than 16%.