ABSTRACT
Heat treatment is one of the most important industrial finishing operations which helps in the improvement of mechanical properties such as hardness, tensile strength and impact strength of components being used in our day-to-day activities. A common method of achieving this is through quenching (agitated and static). An agitated quenching bath with capacity of 0.1m3 and four different speeds of agitation was developed and its performance evaluated. Medium carbon steel and ductile cast iron alloy samples were used for the performance evaluation of the quenching bath. Water at room temperature was used as quenchant. Hardness, impact strength and microstructural analysis tests were carried out on the quenched samples, results obtained and graphs plotted. Quenching in the agitated bath resulted to an increase in hardness and tensile strength, whereby hardness of medium carbon steel increased from 231HBN to 621HBN and that of ductile cast iron from 263HBN to 662HBN. It was discovered that at Speed III (250rpm) the optimum speed to produce maximum increase in hardness.