Research on the Low-Pressure Casting Process of a Double Suction Impeller in 304 Austenitic Stainless Steel with High Performance and Thin-Wall Complex Structure

Abstract The manufacturing of thin-wall complex castings using pressure-assisted casting is one of the most significant challenges for structural applications requiring excellent mechanical properties and fuel. In this paper, efforts have been made to manufacture thin-wall complex structure casting using high-temperature alloys with high strength. Low pressure casting forming process was used to manufacture a double suction impeller in 304 austenitic stainless steel with a thin-wall complex structure. By combining 3D printed sand mold with an optimized low-pressure casting process, a double suction impeller with a thin-wall thickness of 3mm was successfully prepared. The prepared double suction impeller showed structural integrity, smooth surface, and compact structure. The filling and solidification process of the 304 austenitic stainless-steel melts were analyzed using casting simulation software. The casting had an excellent mechanical property with a tensile strength of 595 MPa, yield strength of 265 MPa, and elongation of 48%. Results show that the improved low-pressure casting processes could be applied to the production of thin-wall complex structure parts during high-temperature casting processes. The results are of great significance to the casting of high-temperature alloys.