A dilatometric study of the continuous heating transformations in maraging 300 steel

Abstract

Dilatometric study in maraging 300 steel was carried out to study the effect of heating rate on precipitation of intermetallic phases and martensite to austenite transformation. Solution annealed material were subjected to controlled heating-holding-cooling cycles. The martensite to austenite transformation splits into two steps at lower heating rates. The first step enhanced by slow heating rate, occurs through a diffusion process, while the second step, enhanced by a fast heating rate, occurs though a shear process. The extent of precipitation decreases with heating rate, suggesting that precipitation occurs primarily by a diffusional process.