Effects of Heat Treatment on the Properties of Mild Steel Using Different Quenchants

This study was conducted in order to improve the mechanical properties of mild steel materials used as bolts and studs in coupling agricultural machinery following their frequent failure in service. Heat treatment at 9000C for four hours was done and six specimens of each were then quenched with different media used as the major source of strength enhancement. The universal testing machine (UTM) was utilized for the various mechanical tests. The results of the tests showed positive changes in the strength properties of the mild steel material, in terms of high tensile strength, toughness, ductility and hardness. Water quenched specimen has the highest tensile strength (497.76N/mm2), hardness value (138.27), toughness (168.38) and bending at yield (749.49N/mm2). It also recorded the lowest ductility of 28.36% when compared with ductility values for other quenchants. These desirable qualities are needed for durability in service, especially for rugged agricultural operations like tillage. Water proved to be the best quenchant for achieving these desirable qualities among the quenching media used.