Microstructure and mechanical properties of ASTM A131 EH36 steel fabricated by laser aided additive manufacturing.

In this paper, a direct laser deposition (DLD) process was used to print ASTM A131 EH36 high strength low alloy steel samples in four different orientations, namely, horizontal 0° (XY_0°) & 45° (XY_45°) and vertical 90° (XZ_90°) & 45° (XZ_45°), with an EH36 steel powder. The microstructures, mechanical properties and fracture behavior of the printed materials, were evaluated in detail. Tensile, charpy impact and fatigue tests were conducted to measure the mechanical properties of the materials. The results showed that all the EH36 steel samples printed in the four orientations satisfied the ASTM standards for the tensile and charpy impact properties of EH36 steel. The microstructures of the EH36 steel samples and the thermal cycles encountered in the different build orientations could be tuned by controlling the printing process parameters and scanning method. The microstructure was closely correlated with the mechanical properties of the built samples. The fatigue fracture mechanism of the printed EH36 steel samples was also proposed. Additive manufacturing of near net shape coupons along 4 orientations using EH36 steel powder. [Display omitted] • A131 EH36 steel samples were printed in different orientations through LAAM process. • The tensile, charpy impact and fatigue properties of the samples were evaluated. • The microstructure and mechanical properties of the samples were closely correlated to in-process scanning methods. • The fatigue failure mechanism of the LAAMed EH36 steel was reported for the first time. [ABSTRACT FROM AUTHOR]