The effect of addition rare-earth metal(REM),Ca and Mg elements on the microstructure,toughness of and the formation of intragranular acicular ferrite(IAF) in hot affect zone of large heat-input welded low alloy non quenched-tempered steel plate was investigated.

Thermodynamic analysis on intermediate transformation mechanism of acicular ferrite in welds;

Effects of nonmetallic inclusions on acicular ferrite nucleation in deposited metals of microalloyed steel;

Thermodynamic analysis of pre-eutectoid transition of acicular ferrite in carbon-depleted regions of austenite in Fe-C-X alloys;

The sizes and distribution of the inclusions in HAZ which promote intra-granular ferrite nucleation were measured using the automatic image analyzer, and the figures of the intra-granular ferrite which has self refining grain behavior were observed using transmission electron microscopes with energy dispersiv.

The results show that Ti-containing complex inclusions act as the nuclei for intra-granular ferrites and refine austenite grains, and with Ti added, the area proportion of ductile fracture is increased.

Development of Microalloyed Intragranular Ferrite Steel With High Strength and Toughness;

Effect of secondary thermal cycle on intragranular ferrite;

Influence of carbon content on the formation of intragranular ferrite in isothermally treated medium-carbon vanadium-microalloyed steels;