HYDROGEN BEHAVIOR IN 38KHN3MFA STEEL UNDER VARIOUS CONDITIONS OF ANTIFLAKE TREATMENT

Kinetic regularities of the hydrogen evolution from 38KhN3MFA steel du ring antiflake treatment (AFT) under various conditions were studied b y way of the estimation of change in vacuum due to desorption of hydro gen from previously hydrogenated specimens. For conventional AFT condi tions, the supercooling of the steel into the intermediate range of au stenite decomposition is established to fourfold increase the rate of hydrogen desorption during isothermal holding at temperature of about Ac-1. The cyclic heat treatment (CHT) provides higher dehydrogenation for shorter (by 30 - 40%) time. A thermokinetic analysis of the hydrog en state in the steel before and after CHT showed that the increased e fficiency of CHT is associated with its strong effect on energy stares of hydrogen.