Nano-scaled precipitates in medium carbon V-Ti-N microalloyed steel and its conditioning effect on austenite decomposition
The precipitates composition, mass percent and particle size distribution in medium carbon V-Ti-N microalloyed steel during different sub-processes of N80 grade hot rolling seamless oil well tubes have been investigated by chemical phase analysis, small-angle x-ray scattering,. The results show that there are mainly nano-scaled MC and iron carbon precipitates in the above steel. The type, mass percent and particle size distribution of the precipitates vary with the steel hot working history, especially the controlled cooling temperature. The vanadium precipitation characteristic during the sub-procedures after rolling has notable influence on the metastable iron carbon precipitates which can reflect the homogeneity of austenite composition. The particles containing vanadium are further formed in the reheating procedure when the controlled cooling temperature is 600 ℃, which is beyond the expectation of production line designers. Controlled cooling to 600 ℃ and air cooling after stretch-reduction-diameter deformation promote the formation of C-rich V(C,N) and iron carbon particles with size less than 36 nm, leading to the reduction the carbon and alloy elements in austenite, which promote the intergranular ferrite formation. The contribution of nano-scaled iron carbon precipitate and the interaction with MC particles in medium carbon microallyed steel should be further studied.
LIU Sheng-xin MIAO Jin-Qi LIU Guo-quan YAN Xin-qi ZHANG Yong-gang Ｈuang Jian-kai
School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002, P R China Henan School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002, P R China School of Materials Science and Engineering, University of Science and Technology Beijing, 100083, P Wuxi Seamless Steel Tube Company, Ltd., Wuxi 214026, P R China
国际会议
桂林
英文
1-8
2010-11-16（万方平台首次上网日期，不代表论文的发表时间）