Modelling the hardenability and tempering of high strength steels
Johan Eliasson1, Tadeusz Siwecki1, Björn Rodell2
1Corrosion and Metals Research Institute, KIMAB Drottning Kristinas väg 48, S-114 28 Stockholm, Sweden. 2SSAB Oxelösund AB, Sweden.
DOI:
https://doi.org/10.7494/cmms.2007.1.0120
Abstract:
The aim of the present work was to develop hardenability and tempering models for various quenching and tempering treatments of high strength /martensitic steels. The hardenability model developed at KIMAB is divided in three sub-models: (i) Dissolution of particles during reheating, (ii) Calculation of hardenability distance kinetically depending on the dissolution of particles and (iii) Grain growth (includes the Zener pinning effect of size and volume fraction of the particles). The hardenability model calculates the Ideal Diameter, Jominy distance to 50% martensite and surface hardness of steel after quenching. Examples of the predictions on a steel from SSAB Oxelösund are presented here in the paper in comparison to the experimental data. The tempering model was also developed at KIMAB as an empirical model, which has been based on experimental data from the literature. Hardness and ultimate tensile strength of a quenched steel, originated from Ovako Bar, after tempering in the temperature range 150°-700°C were calculated and the results were compared with the experimental data. The tempering model generally functioned well and good agreement of predictions with experimental data has been obtained. However, the thermal history before quenching is important to take into consideration because this affects the level of hardness and strength. By applying the hardenability model together with the tempering model the effect of undissolved particles on the properties of tempered steels could be studied.
Cite as:
Eliasson, J., Siwecki, T., & Rodell, B. (2007). Modelling the hardenability and tempering of high strength steels. Computer Methods in Materials Science, 7(1), 54 – 60. https://doi.org/10.7494/cmms.2007.1.0120
Article (PDF):
Keywords:
Hardenability, Carbide dissolution, Modelling, Tempering, Grain growth, Microalloyed steels
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