Improvement in mechanical properties of C300 maraging steel by application of VAR process

The prime objective of this research was to improve the mechanical properties of C300 maraging steels originally cast in the vaccum induction melting (VIM) and AIM furnaces by application of vaccum arc remelting (VAR) process. For this purpose two sets of C300 maraging steel with different amounts of Ti were cast in two different types of furnaces. Three bars with 1, 1.5 and 2 wt% of Ti were produced in the argon induction melting (AIM) furnace and two bars with 0.65 and 1 wt% Ti in the VIM furnace. Then all of the bars were subjected to VAR process in order to study the effects of this process on the reduction of N and O gases and inclusions, hence improvement in the mechanical properties. The results show that the total reduction of N and O gases in the bars cast in the AIM furnace was up to 40%, the amounts of inclusions irrespective of their kind reduced up to 30% while ductility and impact energy increased up to 40%. However, these parameters in the bars cast in the VIM furnace changed as follows: total gas reduction decreased by 12%, ductility and impact energy increased by 30% and 47%, respectively. So this research provides a very informative data base for those who are interested in studying the effect of VAR process on the mechanical properties of this kind of cast steel.