ASSESSMENT OF THE INFLUENCE OF STRESSES ON THE COURSE OF THE PHASE TRANSFORMATION PROCESS IN VT 22 ALLOY

摘要

INFLUENCE OF STRESSES ON THE PHASE TRANSFORMATION PROCESSES IN VT 22 ALLOY WITH PRIOR BETA-METASTABLE STRUCTURE. The results of the alloy phase composition assessment by the method of transmission electron microscopy of x-ray phase analysis and the durometric method were used to build a diagram of phase transformations on the basis of which the time and temperature ageing parameters under stress and under no stress were selected ( fig. 1). Ageing at 250 deg c during 20 min, 1 hour and at 300 deg C during 20 minutes does not lead to a disintegration of beta- field accompanied by the formation of isolated particles, however under the influence of the elastic stress of 490 MPa the phase composition changes to beta + omega and beta + omega + alpha respectively (fig. 2).