FE-SEM examination of Microalloyed Hypereutectoid Steels

Equilibrium Model of Precipitation in Microalloyed Steels

The formation of precipitates during thermal processing of microalloyed steels greatly influences their mechanical properties. Precipitation behavior varies with steel composition and temperature history and can lead to beneficial grain refinement or detrimental transverse surface cracks. This work presents an efficient computational model of equilibrium precipitation of oxides, sulfides, nitri...

Dilatometric analysis of cementite dissolution in hypereutectoid steels containing Cr

Cementite dissolution in hypereutectoid steels containing Cr is analyzed using dilatometry combined with the consideration of the carbon content in the austenite. The results suggest that the austenite transformed from the mixture of ferrite and cementite can be approximated to have a carbon content corresponding to equilibrium with ferrite. The overall dissolution behavior of cementite is desc...

Particle-Size-Grouping Model of Precipitation Kinetics in Microalloyed Steels

The formation, growth, and size distribution of precipitates greatly affects the microstructure and properties of microalloyed steels. The computational Particle-Size-Grouping (PSG) kinetic models were developed to simulate precipitate particle growth due to collision and diffusion mechanisms. Firstly, the standard PSG method for collision is clearly explained and verified. Then a new PSG metho...

Mechanism of Abnormal Grain Boundary Ferrite Formation in Hypereutectoid Pearlitic Steels

Effects of tungsten on the hydrogen embrittlement behaviour of microalloyed steels

The effects of tungsten (W) additions (0, 0.1, 0.5 and 1 wt.%) on the hydrogen embrittlement behaviour of microalloyed steels were systematically investigated by means of slow strain rate tests on circumferentially notched cylindrical specimens, and the mechanism of hydrogen-induced embrittlement was discussed. W addition is found to increase the activation energy of hydrogen desorption. Micros...