Calculated alloying effects on irradiation hardening of ferritic steels

Both copper precipitates and depleted zones contribute to calculated irradiation hardening of ferritic steels. In addition, predicted magnitudes of radiation induced solute segregation indicate that segregation can be significant and may influence the irradiation sensitivity of steel at low fluence. Radiation enhanced diffusion accelerates the predicted growth of precipitates but the magnitude of acceleration was less than expected from measured hardening kinetics. The discrepancy between predicted and measured kinetics may be attributed to limitations in the precipitate nucleation and hardening assumptions. The dependencies of precipitate growth and hardening on copper content, precipitate number density and copper diffusion kinetics were predicted. Assumed depleted zone formation resulted in predicted rates of hardening that were consistent with experimental measurements. Simultaneously, growth of precipitates and formation of depleted zones were evaluated. Significant influences of radiation on solute segregation were also calculated. The hardening and segregation influences occurred at low fluence and were insensitive to temperature