On the plasticity of MnS at elevated temperatures and its influence on damage prevalence

Acta Materialia, vol. 291, pp. 120987

Abstract

Forming-induced damage strongly influences the service life and mechanical properties of components made from 16MnCrS5 steel. This damage is initiated in the vicinity of MnS inclusions, which fracture or delaminate at their interfaces due to the mechanical contrast to the steel matrix. Forming processes are often conducted at elevated temperatures; however, the plasticity of MnS at these temperatures in correlation with crystallographic orientation have not been fully explored. In this study, we aim to uncover the high-temperature properties of MnS using micropillar compression and TEM analysis . We then relate them to damage prevalence observed in steel at elevated temperatures with high resolution SEM imaging in combination with AI-assisted damage analysis. We demonstrate that the mechanical contrast of MnS and steel influences the damage prevalence significantly showing a minimum at 400 °C. We additionally determine the CRSS for the primary { 1 1 0 } 〈 1 1 ¯ 0 〉 slip system in the temperature range from 20 °C to 600 °C and the CRSS for the secondary { 1 1 1 } 〈 1 1 ¯ 0 〉 slip system at temperatures of 400 °C and 600 °C. We show that MnS exhibits a yield strength anomaly at 400 °C in specific orientations and at slow loading rates that is accompanied by a change of the active slip system. We relate this yield strength anomaly to thermally activated cross-slip and increased impurity mobility at elevated temperatures.

Authors 8

1. Maximilian A. Wollenweber corresponding Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, 52074 Aachen, Germany

2. Jonas Werner Aachen Central Facility for Electron Microscopy

   RWTH Aachen University

   Affiliation as printed

   Central Facility for Electron Microscopy, RWTH Aachen University, 52074 Aachen, Germany

3. Carl F. Kusche Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, 52074 Aachen, Germany

4. Chunhua Tian Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, 52074 Aachen, Germany

5. Pei‐Ling Sun Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, 52074 Aachen, Germany

6. Jannik Gerlach Aachen Institute of Metal Forming

   RWTH Aachen University

   Affiliation as printed

   Institute of Metal Forming, RWTH Aachen University, 52074 Aachen, Germany

7. Talal Al‐Samman Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, 52074 Aachen, Germany

8. Sandra Korte‐Kerzel Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, 52074 Aachen, Germany