Study of mechanical behaviours and degassing of a high toughness steel during a double melting process

Maraging Steels are a group of steels having high strength and toughness. Presence of inclusions in these steels are harmful for their strength and toughness. Also، there are some active elements within these steels. Therefore، application of advanced melting، refining and casting processes such as vacuum processes are used greatly in production of maraging steels. In this research two C300 maraging steel with 0. 65 and 1 wt% Ti were casted firstly in VIM furnace. Then samples subjected to VAR process in order to study the effects of this process on mechanical properties، inclusions content and gas atoms within the steel. The results show that during VAR process of the bars casted in VIM furnace، the total N and O gases reduced to 14%، ductility and resistane to impact increased up to 30% and 47%، respectively. Comparison of these two steels that produced by VIM+VAR showed that increasing of titanium from 0. 65 to 1 wt% causes marginal increasing in strength and hardness and marginal decreasing in ductility and resistance to impact of steel.