Research on the behaviour and mechanism of void welding based on multiple scales

Abstract As the core foundation of major national equipment, large forgings have a great influence on economic construction, development defence equipment and modern cutting-edge science technology. In production forgings, welding internal void is technical problem that directly affects quality forgings. view phenomenon in behaviour mechanism were deeply studied based stretching test molecular dynamics simulation, combined with lot theoretical analysis. The results show multi-pass deformation kind plastic process which can eliminate defects. When forging ratio reaches 2.2, be welded completely tensile strength restored to level matrix. With increase compression deformation, stress will sharply, especially at grain boundary. addition, main 30Cr 2 Ni 4 MoV steel recrystallization growth mechanism. Recrystallization are significance for promoting reduction volume realizing metallurgical bonding interface.