Cu precipitated in feirite of 0.06C-0.40Cu bainite steel is kept with matrix in semi-coherent Kurdjumov-sachs relation

according to the theory of mismatch dislocation

with increasing temperature the calculated specific interfacial energy between ε-Cu and ferrite matrix increases

the coefficient of diffusion of Cu at 823 K is 1 000 times more than that at 723 K

and the ripening rate of

ε

-Cu increases approximately by 10 times. As ε-Cu precipitated size is 4.5 nm

ripening rate at 520 °C is 0.3127 nm-1/3

the ε-Cu particle size is 9.92 nm

yield strength of steel increases by 142.8 MPa.