Improvement of tensile properties by controlling the microstructure and crystallographic data in commercial pearlitic carbon-silicon steel via quenching and partitioning (Q&P) process

In the current research, a complex microstructure and crystallographic data were developed through quenching partitioning (Q&P) process to improve tensile properties of commercial pearlitic carbon-silicon steel. Two-stage Q&P process, including full austenitization, at 220 °C, followed by two different temperatures, was applied as-received specimen generate composed tempered martensite, bainite, ultrafine carbides/martensite-austenite/retained austenite particles. Microstructure investigated scanning electron microscopy, backscattered diffraction (EBSD), X-ray techniques. Then, hardness evaluated confirm improvement mechanical properties. Dilatation-temperature curves exhibited kinetics martensitic bainitic transformation during isothermal stages. The presence nano-carbide particles inside athermal martensite confirmed microscopy due pre-formed carbon depletion stage coupled with transformation. formation preferential atomic-compact <111> direction in BCC (martensite/bainite) plates characterized EBSD, could enhance ductility providing adequate slip systems. Point-to-point misorientation analyses demonstrated slight dominance low angle boundaries proportion structure Q&P-220-375 specimen, which be used phase characterization. Results revealed that development nanoscale carbide dispersed refined bainite/martensite matrix boosted yield ultimate strength over 100% 110% compared initial microstructure. However, reduced half value Q&P-220-325 specimens.