A hybrid electroslag additive manufacturing method is provided. This hybrid method combines the benefits of wire-arc additive manufacturing with the benefits of electroslag welding and casting. As discussed herein, the hybrid method employs an interleaved wall-and-infill strategy, wherein the wall is manufacturing via wire-arc additive manufacturing or other directed energy deposition, and the infill is provided by electroslag welding/casting techniques or similar processes, such as submerged arc welding. The hybrid method can produce large, complex components at higher rates with lower lead times than either of the techniques individually.

A flux for electroslag welding used for electroslag welding may include a basic oxide, an amphoteric oxide, an acidic oxide, and a fluoride. With respect to a total mass of the flux, the basic oxide may include 5.1 mass % or more and 30.0 mass % or less of CaO, the acidic oxide includes 17 mass % or less of SiO.sub.2, and the fluoride includes 35 mass % or more and 73 mass % or less of CaF2. A content of the CaO is 30 mass % or more with respect to a total mass of the basic oxide, a content of the SiO.sub.2 is 80 mass % or more with respect to a total mass of the acidic oxide, a content of the CaF.sub.2 is 80 mass % or more with respect to a total mass of the fluoride, and a value of (2[CaF.sub.2]+[CaO])/[SiO.sub.2] is 5 or more and 56 or less.

A flux for electroslag welding used for electroslag welding may include a basic oxide, an amphoteric oxide, an acidic oxide, and a fluoride. With respect to a total mass of the flux, the basic oxide may include 5.1 mass % or more and 30.0 mass % or less of CaO, the acidic oxide includes 17 mass % or less of SiO.sub.2, and the fluoride includes 35 mass % or more and 73 mass % or less of CaF2. A content of the CaO is 30 mass % or more with respect to a total mass of the basic oxide, a content of the SiO.sub.2 is 80 mass % or more with respect to a total mass of the acidic oxide, a content of the CaF.sub.2 is 80 mass % or more with respect to a total mass of the fluoride, and a value of (2[CaF.sub.2]+[CaO])/[SiO.sub.2] is 5 or more and 56 or less.