Using a new valence electron structure(VES) calculation model of high temperature austenite,the VES of Fe-0.4%C austenite at 900 ℃ was investigated. The results show that the influence of temperature on VES is remarkable.
The effects of nitrogen content on austenite grain size at high temperature and impact toughness of simulated welding HAZ and actions of second phase particles(Ti,Nb)N in series low carbon Ti-Nb microalloyed weldable steels were studied.
The amounts of rare-earthelements added in the steel varied from 0 to 0.038% (or the ratio of RE to sulphur from 0 to 1.5)It was found that three brittle phases Ti_2SC, Ti(CN) and M_(23)(CB)_u, rather than MnS-phase occurredat the facets of overheated fracture surfaces.
This paper has developed two BP network models relating austenite grain size and softening fraction with hot working parameters in microalloyed steel on the basis of experimental data in gleeble-1500 system.
Intergranular fracture susceptibility, as determined by scanning electron microscopy, was increased by reduced rates of cooling during quenching, high austenitizing temperature, and high P content.
The dissolution of iron-borocarbides in austenite is complete at 1100 °C and precipitation along γ grain boundaries of this boron-bearing phase was observed after water-quenching from high austenitizing temperature.
Effects of high austenitizing temperature and austenite deformation on formation of martensite in Fe-Ni-C alloys
A high austenitizing temperature and subsequent rolling favor retention of the effect of HTTMT.
If a high austenitizing temperature is used, much less nitrogen segregrates so fewer nitrides precipitate during the quench.