Toughness variation of carbon steels using heat treatment

Toughness is the important mechanical properties of material that is a measure of the ability of a material to absorb energy up to fracture in dynamic loading and high strain rate conditions. For a material to be tough it must display both strength and ductility; and often, ductile materials are tougher than brittle ones. Impact tests are an almost direct measurement of toughness that charpy test is a popular test for this purpose. In this paper this type of test was used to predict the toughness of carbon steel. The influence of microstructural properties consists of type of phase structures and grain size resulted of heat treatment on toughness has been investigated using this study. Indeed effects of heat treatment parameters such as cooling rate and annealing condition (temperature and time) on toughness studied. Results obtained from impact tests show that the cooling rate from austenite temperature is the most important parameter on toughness, as the material toughness decreases with increasing the cooling rate. Toughness of this material decreases with increasing the holding time and temperature of annealing process.

کلیدواژه ها:

Heat treatment ، Impact test ، Microstructure ، Toughness