Influence of heating rate on the alpha?gamma-transformation critical temperatures in 40Kh steel

Abstract

1. In heating at rates of vh≅0.7–36 deg/sec 40Kh steel with an original ferritic-pearlitic structure has higher critical α→γ-transformation temperatures than with a martensitic structure. 2. With heating rates up to ∼3 deg/sec the critical transformation temperatures of 40Kh steel with original ferritic-pearlitic and martensitic structures do not change. 3. With an increase in heating rate aproximately from 9 to ∼100 deg/sec for specimens with a ferritic-pearlitic structure with a practically unchanged Ac1 tee Ac3 temperature increases significantly. For specimens with a martensitic structure with an increase in vh from 9 to 36 deg/sec both temperatures drop simultaneously.