Rotavator blades are prone to significant wear because of the abrasive nature of sand particles. The aim of this research work is to investigate the effect of cryogenic treatment and post tempering on abrasive wear behavior, in the presence of angular quartz sand (grain size of 212–425 μm), of rotavator blade material of boron steel (30MnCrB4). Cryogenic treatment has caused an improvement in the abrasive wear resistance and microhardness of 30MnCrB4 by 60% and 260.73%, respectively, compared to untreated material due to enhancement in hardness, the conversion of retained austenite into martensite, and the precipitation of secondary carbides in boron steel after exposure to cryogenic temperature. Economic analysis justifies the additional cost of cryogenic treatment.
20 September 2019 in Journal of Materials Engineering and Performance
The poor fatigue strength of Ti-6Al-4V ELI is a main cause of failure in structural implants. In this work, Ti-6Al-4V ELI was subjected to β-solution treatment to obtain martensite microstructure and further subjected to −196 °C for 24 h. Significant improvement in high cycle fatigue performance of martensite Ti-6Al-4V ELI was observed on exposure to cryogenic cycle. Resistance to fatigue crack growth of alloy was augmented in martensite structure as compared with mill annealed sample and the same was retained even after exposure to cryogenic treatment. The variation observed in fatigue behavior due to cryogenic treatment was correlated with fractography and metallurgical investigations. Improvement in high cycle fatigue performance can be attributed to a combined effect of a decrease in the size of prior β grain, formation of massive α patch and its subsequent transformation into ultra-fine α and β during the soaking period at −196 °C.