ABSTRACT
The effects of Al addition on austenite grain growth and particle characterization in heat-affected zone during high-heat-input welding for Mg- deoxidized steel plates without Al (0Al) and with 0.02wt-% Al (200Al) were studied. Austenite grains grow intensively in 1300–1400 °C and TiN particles play the role on inhibiting grain growth. The number density and average size of submicron and nanometer particles decreases and increases, respectively with Al addition. There are critical dissolved particle sizes of 1.84, 3.18 and 11.64 nm at 1300, 1350 and 1400 °C, respectively. The dissolution of nanoparticles in 0Al larger than that in 200Al causes the faster reduction rate of pinning force and greater increase of grain growth rate in 0Al. The effect of submicron particle coarsening on austenite grain growth is non-obvious because the amount of submicron particles is less than that of nanoparticles and the submicron particle coarsening is a comparatively slow process.
Disclosure statement
No potential conflict of interest was reported by the author(s).