Microalloyed 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...

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...

Comments About the Strengthening Mechanisms in Commercial Microalloyed Steels and Reaction Kinetics on Tempering in Low-Alloy 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...

Heat affected zone microstructures and their influence on toughness in two microalloyed HSLA steels

Microstructures and Charpy impact properties have been examined in two microalloyed steels following heat treatments to simulate weld heat affected zone (HAZ) structures over a range of heat input conditions, characterised by the cooling time from 800 to 500 !C (Dt8/5). The base materials were low carbon structural steel plates microalloyed with vanadium and nitrogen (V–N) and niobium (Nb), res...