Strength differential effect in four commercial steels

The difference between compressive and tensile flow stress of a material at a given strain termed as strength differential (S-D) effect, has been eval uated in case of four commercial steels via a series of heat treated condit ions. The results have unequivocally established that the magnitude of S-D was maximum in the as quenched condition and tempering of the quenched stru cture led to a decrease in S-D. Spheroidised and/or annealed structures exh ibited the lowest value of S-D. A linear relationship of S-D value with har dness and mean stress for each case has been established. Attempts have bee n made to explain the observed S-D effect in terms of models based on atomi c mechanism and of continuum mechanics. (C) 2000 Kluwer Academic Publishers .