Effect of multi-walled structure on microstructure and mechanical properties of 1.25Cr-1.0Mo steel fabricated by GMAW-based WAAM using metal-cored wire

Wire-arc additive manufacturing (WAAM) offers multiple benefits, such as high metal deposition, low capital cost, suitable mechanical properties, and reasonable costs. In the present work, Gas metal arc welding (GMAW) based WAAM was employed to manufacture a multi-walled component of 1.25Cr-0.5Mo at optimized parameters using metal-cored wire. The fabricated multi-walled structure was observed with seamless fusion and free from disbonding. The fabricated multi-walled component was studied through microstructure investigations, mechanical properties such as microhardness (MH), tensile test, and impact test at various positions (top side, middle side, and bottom side) of the built structure. Microstructure results have shown a tempered martensite structure in the bottom zone with coarse grains and finer microstructures in the middle and top zones. MH values throughout the component were uniform and thus indicated a similar nature to the multi-walled component. A comparison of tensile properties was carried out among the results of metal-cored wires and multi-walled structures to check the internal eminence of the obtained component. For all sides of the multi-walled structure, all the tensile properties were found to be in the range values of 1.25Cr-0.5Mo metal-cored wire. The results of all three conditions for impact toughness showed far better strength than the requirement. Fracture surface morphologies of tensile and impact test parts showed the presence of large dimples with the homogenous distribution. Thus, all the obtained results have suggested the suitability of the GMAWAM process for the fabrication of a multiwalled structure of 1.25Cr-0.5Mo metal-cored wire for various industrial applications.(c) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

Wire-arc additive manufacturing (WAAM) is a promising technology for the fabrication of multi-walled components. This study employed Gas metal arc welding (GMAW) based WAAM to manufacture a 1.25Cr-0.5Mo multi-walled component. The fabricated structure showed seamless fusion and no disbonding. Microstructure investigations revealed different grain structures in different zones of the component. Mechanical property tests, including microhardness, tensile, and impact tests, demonstrated that the fabricated component had suitable mechanical properties. Comparisons with the results of metal-cored wires confirmed the high quality of the obtained component. The findings suggest that GMAWAM is suitable for the fabrication of multi-walled structures for various industrial applications.