Nano-Scaled Fe3C Precipitates and Precipitation Strengthening in Hot Rolled Low Carbon High Strength Titanium Microalloyed Steel
Hot rolled Ti microalloyed steel with polygonal ferrite and granular bainite microstructure and 640 MPa yield strength has been developed in BOF-CSP process. By chemical phase analysis, XRD, EDS and high resolution TEM, the particle size distribution, morphology, composition, crystal structure of precipitates were identified. Results revealed the steel containing Ti exhibits fine and uniformly distributed Fe3C-type carbides, the amount of M3C particles less than 18 nm in size was 0.2565 mass %. The high strength of steel is attributed to the precipitation strengthening effect of Fe3C, the yield strength increment from precipitation strengthening of Fe3C calculated according to the formula by Olson and Ashby-Orowan attained 234.4 MPa.
Sihai Jiao, Zhengyi Jiang and Jinglong Bu
J. F. Wang et al., "Nano-Scaled Fe3C Precipitates and Precipitation Strengthening in Hot Rolled Low Carbon High Strength Titanium Microalloyed Steel", Advanced Materials Research, Vols. 146-147, pp. 838-843, 2011