Improve the manufacturing efficiency of steel bars by using hot-wire pulse arc additive manufacturing

With the advantages of high material utilization and freedom of structural form, wire and arc additive manufacturing (WAAM) is a feasible solution to achieve fully automated construction of buildings. However, the current manufacturing efficiency of steel bars manufacture using WAAM is not sufficient for construction industry applications. This paper uses hot-wire pulse arc additive manufacturing (HWPAAM) to improve the manufacturing efficiency of 316L stainless steel (316L SS) bars. The efficient manufacturing principle of HWPAAM 316L SS bars was analyzed in this article. The effect of different manufacturing efficiency on heat input, macrostructure, microstructure, and mechanical properties of 316L SS bars was studied. The results show that the manufacturing efficiency of the 316L SS bar manufactured by HWPAAM can reach 31 mm/min. The connection rate of hot-wire power supply can be improved to 96.7 % and the heat input of the arc can be reduced by 65 % at 31 mm/min manufacturing efficiency. With the decrease of arc heat input, the grain size decreases. The improvement of manufacturing efficiency has little effect on the macrostructure of the 316L SS bar. Under uniaxial tension, the mechanical properties of the 316L SS bar standard specimen with different manufacturing efficiencies are basically the same. By using this manufacturing process, the manufacturing efficiency of the 316L SS bar is greatly improved while the performance is not significantly reduced.