Quench severity of AISI 1045 steel utilizing intensive spray quenching

An intensive spray quench tank was designed and built at Missouri S&T to improve the mechanical properties of quenched and tempered steels. Intensive spray quenching offers high heat extraction, higher quench severities, and less water consumption than typical immersion quenching baths. The creation of compressive residual stresses during intensive quenching can also result in less distortion and cracking as well as improvement in fatigue properties.

In this study, the development of the intensive quenching system is described and the quench severity as a function of spray nozzle pressure was evaluated using AISI 1045 steel and determined using the Kern method. Two-inch diameter and eight-inch long test bars were quenched using three different pressures in the spray unit. Jominy bars from the same steel grade were also tested for hardenability. Test bars and Jominy samples were heat-treated at 850ºC per 1.5hr before quenching. From the Jominy, hardness quench profile was measured, and from the test bars diametral and radial hardness were obtained and related to the Jominy distance obtained in the Jominy test to determine the quench severity. These results were compared to previous results for a immersion quench tank with forced convection.