GROWTH OF ALLOY CARBIDE PARTICLES IN AUSTENITE.

Abstract

The growth of Cr//7C//3, Mo//6C, VC and NbC carbides in austenite was examined in ranges of temperature from 1173 to 1473 K and time from 10 to 200 h. Growth of carbides occurs initially by taking the solute from the matrix until an equilibrium is attained, and later by Ostwald ripening. For the carbides with lower growth rates, higher heating temperatures and/or longer times were required to reach equilibrium. The rate equation in the stage of Ostwald ripening was derived for the case in which lattice diffusion of M atoms controlled the growth rate.