Fatigue characterization of wire arc additive manufactured AWS ER100S-G steel: fully reversed condition

Abstract

To overcome the limitations associated with the conventional fabrication (e.g., casting, forging, assembly) of large-sized complex structures, in this study, we assess large format additive manufacturing (wire arc additive manufacturing) as a potential replacement using high-strength low alloy wire feedstock (AWS ER100S-G). The process/microstructure/property/fatigue correlations of AWS ER100S-G (a low carbon high strength electrode filler utilized in gas metal arc welding) fabricated by wire arc additive manufacturing (WAAM) are presented in detail. Characterization tools such as the optical microscope, scanning electron microscope with electron backscattered diffraction, μ-CT scan, and mechanical testing (tensile, hardness, fully reversed fatigue tests) were utilized to quantify the property correlation of the WAAM’d AWS ER100S-G. To identify the controlling mechanism of fatigue crack initiation and fatigue crack growth pattern, scanning electron microscopy-based fractography assessments were conducted on the fracture surface of the broken specimens. Our findings were then compared against WAAM’d chemically closed steel (e.g., AWS ER100S-1 and AWS ER70S-6) reported in the literature. Regarding fatigue performance, the AWS ER100S-1 outperformed the studied AWS ER100S-G, and the AWS ER100S-G outperformed the AWS ER70S-6.