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S. Zamberger, T. Wojcik, G. Klösch, E. Kozeschnik:
"The influence of nitrogen on the precipitation kinetics in microalloyed medium carbon steel";
Talk: THERMEC´2016, Graz (invited); 2016-05-29 - 2016-06-03.

Three melts with different N contents, 35 to 85 ppm wt%, are produced via vacuum induction melting and casting. Target of the present work is to investigate the influence of traces of N on the precipitation kinetics of Nb-Ti microalloyed, medium carbon steel during processing. The material is investigated experimentally by means of light optical microscopy, scanning electron microscopy, electron microprobe analysis and for the fine scaled particles transmission electron microscopy is applied. Numerically, the precipitation kinetics is calculated with the thermokinetic software package MatCalc based on the time-temperature profile of the solidification and rolling process of the material and the final quench and tempering heat treatment. The inhomogeneous chemical composition and microstructure of the as-cast condition is considered via a Scheil-Gulliver Simulation to estimate the chemical composition of the steel after casting. This information is the starting condition for the diffusion simulation where the change of the microsegregation and the precipitation kinetics during further processing is investigated. The experimental findings and simulation results are in good agreement.