Quantification of Vanadium Precipitates after Reheating Slab Steel by Synchrotron X-Ray Absorption Spectroscopy (XAS)
High Strength Low Alloy (HSLA) steels or microalloyed steels are developed in order toimprove the strength and toughness compared with conventional carbon steels. During the reheatingprocess at 1250-1300 °C for a few hours, the furnace consumes large amount of energy, and the slabsuffers from thick oxide scale. This results in significant mass loss. The long reheating time ensuresmaximum dissolution of the microalloying elements, which must be kept to precipitate duringcooling at the end of the hot rolling process. To minimise the reheating time and save the energyconsumption, this research studied the dissolution kinetics of vanadium in HSLA steel. Vanadium isa main microalloying element added to provide higher strength mainly by precipitation hardening. Itis supposed to be dissolved readily according to the solubility limit. The samples were reheated to1200 °C and 1250 °C for 0, 10, 30, and 60 s. After that the fraction of vanadium dissolved in the solidsolution and the remaining undissolved phases of VC, CN, and V(C,N) were measured bysynchrotron XAS. As soon as the sample reaches as low temperature as 1200 °C, a large atomicfraction of 0.878 of vanadium can be dissolved in the solid solution.
Somrerk Chandra-ambhorn, Dr. Wanlop Harnnarongchai, Chantaraporn Phalakornkule, Prof. Piti Sukontasukkul and Mitsutoshi Ueda
A. Worabut et al., "Quantification of Vanadium Precipitates after Reheating Slab Steel by Synchrotron X-Ray Absorption Spectroscopy (XAS)", Key Engineering Materials, Vol. 728, pp. 20-25, 2017