EVALUATING METHOD FOR DETERIORATION DEGREE OF HEAT RESISTING LOW ALLOY STEEL

摘要

PURPOSE:To quickly evaluate the degree of deterioration of the heat resisting low alloy steel which is used at a high temperature and with high accuracy from the variation of eduction density of a fine carbide V4C3 of the heat resisting low alloy steel containing V and the degree of recovery of the dislocated formation of a matrix. CONSTITUTION:A relative formula phiC=f(D) between the creep deterioration degree phiC and the eduction density D of a fine carbide V4C3 is obtained along with a relative formula phiC=g(W) with the recovery degree W of the dislocated formation of a matrix respectively from a sample material. Then the creep deterioration degree after the aging of the real material to be evaluated is obtained in the first half period of the creep deterioration from a formula phiC= f(D) and based on the density D of V4C3 and in the latter half period from a formula phiC=g(W) and from the recovery degree W respectively.