Microstructure and mechanical properties of S30432 steel modified by trace TiC/TiB2 nano-particles.

In this work, S30432 steel containing trace TiC/TiB 2 nano-particles was manufactured, and the effects of TiC/TiB 2 nano-particles on the microstructure and room and high-temperature mechanical properties of the S30432 steel were investigated. The addition of trace TiC/TiB 2 nano-particles can reduce the grain size from 19 ± 2.3 μm to 13 ± 4.5 μm. This is because the nano-particles provide efficient nucleation sites and constrain dendrite growth. Trace nano-particles can simultaneously enhance the strength and plasticity of the S30432 steel at room temperature. At high temperature of 600 °C, the S30432 steel with trace TiC/TiB 2 nano-particles can still maintain high strength and plasticity. However, as the ambient temperature increases, the strength increment of the S30432 steel with trace TiC/TiB 2 nano-particles decreases gradually, while the elongation increment significantly increases. The dynamic recrystallization process is promoted by the addition of nano-particles, causing an increased softening degree. Trace TiC/TiB 2 nano-particles exhibit good plasticizing effect. [ABSTRACT FROM AUTHOR]