Effect of powder oxygen content on microstructure and mechanical properties of a laser additively-manufactured 12CrNi2 alloy steel

Two 12CrNi2 alloy steel powders, one with high-O content (5300 ppm) and the other with lower O content (280 ppm), have been used for laser melting deposition (LMD) additive manufacturing. The lower O content powder fed into the laser molten pool forms an alloy steel without porosity but with higher austenite volume fraction, which leads to significant increases in both tensile strength and ductility. The findings are discussed and interpreted. (C) 2018 Elsevier B.V. All rights reserved.