Research on Life Span of Non-alloyed Piercing Diefor Shell

The research involves the feasibility of enhancing the life span of the piercing die for shell by replacing the die material of the ferrite-pearlite rare earth Mg-Mo nodular iron with the non-alloyed austenite-bainite nodular iron.The result shows that the smelting process of nodulizing plus secondary inoculation has improved the as-cast properties of the piercing die,and that the austenite-bainite structure is formed in the working layer of the die owing to the heat treatment processes,including 3-hour long austenization at 900℃,3-hour long isothermal treatment at 400℃and two-liquid quick-cooling with water and oil.Thanks to the said smelting and heat treatment processes,the mechanical properties of the austenite-bainite nodular iron-made piercing die have been improved,and its service life prolonged.