Effect of Inoculant Containing Si and Ba on Microstructure and Mechanical ‎Properties of Ferritic Ductile Iron Castings ‎

The effect of chemical composition and amount of inoculant on microstructure specially ferrite phase and graphite nodule count and mechanical properties containing ultimate tensile strength (UTS) and hardness of ferritic ductile iron were considered. In this project, three conditions were evaluated. They were without inoculant, barium and silicon base inoculants were used. Inoculant percentages were 0.1, 0.15 and 0.2 percent. The results show that inoculation encourages the ferrite formation from 75 percent to 90 percent in matrix, increasing the nodule count from 125 to 175, decreasing the hardness from around 200 HB to close 160 HB and decreasing the UTS from more than 500 MPa to close the 400 MPa. In comparison between barium and silicon base inoculants, it was seen that effect of inoculants on the microstructure was same but on the mechanical properties was different and barium base inoculant had more appropriate effect in comparison with silicon base inoculant.