The variation of storage and heat energy in AISI 304 under plastic deformation

The results of the analysis of heat and stored energy variation in stainless steel AISI 304 under tension are presented in this work. The distributions of temperature and strain on the surface of specimens have been obtained by using infrared thermography and the digital image correlation of laser speckle patterns techniques. It has been found that the plastic flow diagram consists of two linear stages. The first one is characterized by the monotonic growth in evolved heat. At the second linear stage the portion of stored energy rises, that is connected with the growth in the rate of martensitic transformations. A temperature fluctuation in the center of a specimen at the true strain over 0.4 appears due to the motion of localized strain bands, which are also the sources of heat. nema