Effect of V-Mn-Cr inoculant on microstructure and mechanical properties of grey cast iron

ABSTRACT

In this study, the effects of different composition V-Mn-Cr inoculants on the microstructure and mechanical properties of GCI were investigated through Optical microscope (OM), Scanning electron microscope (SEM), Energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), etc. The results showed that the optimum quantity of inoculant was 7% V, 1% Mn and 6% Cr, and compared with the commercial inoculant samples, the tensile strength, Brinell hardness, and elastic modulus of the V-Mn-Cr inoculant samples increased by 16.7%, 14.2%, and 12.8%, respectively. V-Mn-Cr inoculants were found to refine austenite, graphite, pearlite and eutectic cells size, reduce pearlite lamellar spacing, and increase pearlite and eutectic cells number, thus improving mechanical properties. In addition, graphite nucleation substance may consist of oxides (SiO₂, FeO, Cr₂O₃), carbides (SiC, TiC), sulfides (MnS, FeS), and XO·SiO₂ silicates (X: Mn, Fe, Ca).

KEYWORDS:

• Grey cast iron
• graphite nucleation
• inoculant
• mechanical properties
• thermodynamics
• microstructure
• orthogonal experiment
• heterogeneous nucleation

Acknowledgements

The authors acknowledge and thank the Zhengzhou University Analytical and Testing support.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.