Origins and Resulting Effects of Internal Stresses in Martensite

This paper aims to present new observations and relate these to other recent findings concerning the influence of local micro-stresses (Type II residual stresses) on the behaviour of martensitic steels. A major source of these stresses is the shearing that accompanies phase transformation in individual austenite grains and which is blocked by constraint from the surrounding matrix. Residual stresses are the principal reason for early plasticity and gradual yielding during tensile testing of martensite.