An Assessment of the Microstructure and Mechanical Propertiesudof 0.26 Low Carbon Steel under Different Cooling Media:udAnalysis by one-way ANOVA

摘要

This study reports the effect of heat treatment on the microstructure and mechanical properties of 0.26% lowudcarbon steel at 850oC using different cooling media. Annealing, normalizing and age-hardening heat-treatmentsudwere used for the experimental work. Hardness tests, fatigue tests, compression tests and metallography wereudcarried out on the heat-treated and control samples. The results were further analyzed using the one-way ANOVAudtest. The results obtained showed significant differences in the microstructure and mechanical properties of theuddifferent heat-treated samples. The hardness profile determined using a Brinell ball indenter showed decrease inudhardness of the heat-treated samples when compared with the control. Normalizing heat-treatment yielded audmicrostructure of better quality than annealing and age-hardening. A higher compressive strength of 155.97MPaudand 151.52MPa was obtained with normalizing and annealing heat treatments respectively in comparison to agehardeningud(149.93MPa), and the control test (150.56MPa). Improved fatigue strength was also obtained withudannealing heat treatment. ANOVA test confirmed the results at 90% confidence and further showed that thereudwas significant difference between the four test conditions