Prediction of the Warm Prestressing Effect on an Increase in the Brittle Strength of Crack-Containing Heat-Resistant Structural Steels. Part 1. Model and Procedure of Calculating the Warm Prestressing Effect

The physicomechanical model of warm prestressing and the procedure of calculating this effect for heat-resistant steels are proposed. The procedure is based on the analysis of stress-strain state variations in the elementary volume of the material near the crack tip during warm prestressing and further loading. This procedure takes account of such factors as crack tip blunting, residual stresses, and strain hardening of the material near the crack tip, which determine the effect of warm prestressing on the brittle strength of heat-resistant steels.