Computational design of a novel medium-carbon, low-alloy steel microalloyed with niobium
|Author:||Javaheri, Vahid1; Nyyssönen, Tuomo2; Grande, Bjørnar3;|
1Department of Material Engineering and Production Technology, University of Oulu, P.O. Box 4200, Oulu, Finland
2Materials Science Research Group, University of Tampere, Tampere, Finland
3R&D Engineer, EFD Induction a.s, Skien, Norway
|Online Access:||PDF Full Text (PDF, 2.8 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2018050721981
|Publish Date:|| 2019-04-24
The design of a new steel with specific properties is always challenging owing to the complex interactions of many variables. In this work, this challenge is dealt with by combining metallurgical principles with computational thermodynamics and kinetics to design a novel steel composition suitable for thermomechanical processing and induction heat treatment to achieve a hardness level in excess of 600 HV with the potential for good fracture toughness. CALPHAD-based packages for the thermodynamics and kinetics of phase transformations and diffusion, namely Thermo-Calc® and JMatPro®, have been combined with an interdendritic segregation tool (IDS) to optimize the contents of chromium, molybdenum and niobium in a proposed medium-carbon low-manganese steel composition. Important factors taken into account in the modeling and optimization were hardenability and as-quenched hardness, grain refinement and alloying cost. For further investigations and verification, the designed composition, i.e., in wt.% 0.40C, 0.20Si, 0.25Mn, 0.90Cr, 0.50Mo, was cast with two nominal levels of Nb: 0 and 0.012 wt.%. The results showed that an addition of Nb decreases the austenite grain size during casting and after slab reheating prior to hot rolling. Validation experiments showed that the predicted properties, i.e., hardness, hardenability and level of segregation, for the designed composition were realistic. It is also demonstrated that the applied procedure could be useful in reducing the number of experiments required for developing compositions for other new steels.
Journal of materials engineering and performance
|Pages:||2978 - 2992|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
216 Materials engineering
The authors are grateful for financial support from the European Commission under Grant Number 675715—MIMESIS—H2020-MSCA-ITN-2015, which is a part of the Marie Sklodowska-Curie Innovative Training Networks European Industrial Doctorate programme.
|EU Grant Number:||
(675715) MIMESIS - Mathematics and Materials Science for Steel Production and Manufacturing
© ASM International 2018. This is a post-peer-review, pre-copyedit version of an article published in Journal of Materials Engineering and Performance. The final authenticated version is available online at: http://dx.doi.org/10.1007/s11665-018-3376-9.