J. Phys. IV France 120 (2004) 563-570
Precipitation kinetics of NbC in ferrite of a Nb microalloyed steelY.-H. Choi1, H.-C. Shin2, C.-S. Choi3 and Y.-K. Lee1
1 Department of Metallurgical Engineering, Yonsei University, Shinchon-dong 134, Seodaemun-ku, Seoul 120-749, Korea
2 POSCO Technical Research Laboratories Sheet Product & Process Research Group, Pohang, PO box 36, 1 Goedong-dong, Nam-gu, Pohang, Gyeongbuk 790-785, Korea
3 Research Institute of Iron and Steel Technology, Yonsei University, Shinchon-dong 134, Seodaemun-ku, Seoul 120-749, Korea
The precipitation kinetics of NbC in ferrite matrix of a Nb microalloyed steel was investigated experimentally and numerically. The change in electrical resistivity due to NbC precipitation was measured at different constant temperatures as a function of holding time and was converted to the precipitation kinetics of NbC using a lever rule. The precipitation kinetics was compared with a classical nucleation and growth model and with the hardness. There is a good match among the calculated and measured precipitation kinetics of NbC and the hardness. The numerical and experimental results have been used to construct a precipitation-temperature-time diagram of NbC in ferrite matrix of the Nb microalloyed steel.
© EDP Sciences 2004