TY - JOUR

T1 - Ab initio study of alloying Impact on the stability of cementite in transformation-Induced plasticity-assisted advanced steels

AU - Sakic, Amin

AU - Hofer, Christina

AU - Schnitzer, Ronald

AU - Holec, David

N1 - Publisher Copyright: © 2022 The Authors. Advanced Engineering Materials published by Wiley-VCH GmbH.

PY - 2022/9/18

Y1 - 2022/9/18

N2 - Transformation-induced plasticity (TRIP) steels from the third generation of advanced high-strength steels (AHSS) contain Si additions to prevent the formation of carbides. Cementite (Fe3C) is a prototype among the carbides, and despite the importance of the influence of alloying elements on its stability, mechanisms by which the elements act have not been clarified so far. Herein, ab initio calculations are employed to study the impact of several alloying elements, including Al, Cr, Mg, Mn, and Si, on the stability of cementite. Partitioning energies are calculated to determine the segregation tendency of alloying elements between the phases such as ferrite, austenite, and cementite. The change in formation energy between the alloyed cementite and the pure cementite is then used to quantify the phase (de)stabilization. Therefore, both the partitioning energy and the change in formation energy must be considered together in a multiphase alloy system to make statements about the effect of alloying elements on the cementite stability are proposed. In addition, the effects of the technically most important elements Al and Si on the mechanical properties of cementite are calculated using the stress–strain method. Both the elements are found to increase the elastic stability of cementite.

AB - Transformation-induced plasticity (TRIP) steels from the third generation of advanced high-strength steels (AHSS) contain Si additions to prevent the formation of carbides. Cementite (Fe3C) is a prototype among the carbides, and despite the importance of the influence of alloying elements on its stability, mechanisms by which the elements act have not been clarified so far. Herein, ab initio calculations are employed to study the impact of several alloying elements, including Al, Cr, Mg, Mn, and Si, on the stability of cementite. Partitioning energies are calculated to determine the segregation tendency of alloying elements between the phases such as ferrite, austenite, and cementite. The change in formation energy between the alloyed cementite and the pure cementite is then used to quantify the phase (de)stabilization. Therefore, both the partitioning energy and the change in formation energy must be considered together in a multiphase alloy system to make statements about the effect of alloying elements on the cementite stability are proposed. In addition, the effects of the technically most important elements Al and Si on the mechanical properties of cementite are calculated using the stress–strain method. Both the elements are found to increase the elastic stability of cementite.

KW - Ab initio

KW - cementite stability

KW - TRIP-assisted steels

UR - https://pure.unileoben.ac.at/portal/en/publications/ab-initio-study-of-alloying-impact-on-the-stability-of-cementite-in-transformationinduced-plasticityassisted-advanced-steels(1855d612-a3fe-4b6a-828c-3f6e493f79c0).html

U2 - 10.1002/adem.202200532

DO - 10.1002/adem.202200532

M3 - Article

VL - 24.2022

JO - Advanced engineering materials

JF - Advanced engineering materials

SN - 1438-1656

IS - 11

M1 - 2200532

ER -