Phase transformations and an elastic springback in deformed stable and metastable sheet steels

Martensitic transformation and stress relaxation in cold-deformed metastable steels

“…Measurements of the residual stresses in the internal and external surfaces of vertical parts of samples ( Table 2) have showed that if transformation has been completed in martensitic state (Cr15Ni5Cu2 oNb i, Cr18Ni6Cu2 o i and Cr18Ni2Mn2VN steels) tensile residual stress act in internal surface of the sample (TC zone) while the compressive residual stress in external surface. In the case of the martensitic transformation was incomplete and deformation finished in martensitic-austenitic state (Cr15Ni5Cu2 oV iN and Cr16Ni5Cu2 oV iN steels) an opposite effect was observed, compressive residual stress in internal surface, ESOMAT 2009 04009-p. 3 while tensile in external surface. Residual stress was close to zero in internal surface for deformed stable austenitic steel while in external surface, a low tensile stress acted for deformed stable austenitic steels.…”

“…Particularly, this is an alternating bending with tension, and this state determines the residual shape of a certain section (Fig. 1) [3]. The elastic aftereffect can be evaluated using several shape deviation parameters of d and the radius of residual curvature R provided the radius of residual curvature R aftereffect after unloading of the article.…”