Qualitative Investigation of Damage Initiation at Meso-Scale in Spheroidized C45EC Steels by Using Crystal Plasticity-Based Numerical Simulations

Muhammad Umar,Ulrich Prahl,Faisal Qayyum,Muhammad Umer Farooq,Sergey Guk

doi:10.3390/jcs5080222

Abstract

This research uses EBSD data of two thermo-mechanically processed medium carbon (C45EC) steel samples to simulate micromechanical deformation and damage behavior. Two samples with 83% and 97% spheroidization degrees are subjected to virtual monotonic quasi-static tensile loading. The ferrite phase is assigned already reported elastic and plastic parameters, while the cementite particles are assigned elastic properties. A phenomenological constitutive material model with critical plastic strain-based ductile damage criterion is implemented in the DAMASK framework for the ferrite matrix. At the global level, the calibrated material model response matches well with experimental results, with up to ~97% accuracy. The simulation results provide essential insight into damage initiation and propagation based on the stress and strain localization due to cementite particle size, distribution, and ferrite grain orientations. In general, it is observed that the ferrite–cementite interface is prone to damage initiation at earlier stages triggered by the cementite particle clustering. Furthermore, it is observed that the crystallographic orientation strongly affects the stress and stress localization and consequently nucleating initial damage.

Highlights

The critical factor in the exponential growth of the mobility, mechanization, and infrastructure sectors in the last six to seven decades is the improvement in the existing and development of novel steel materials [1]
The influence of cementite particle size, distribution, and clustering in the ductile ferrite matrix has a decisive effect on the overall mechanical behavior of the material
The local stress points in cementite are observed as high as ~10GPa, while the average local stress shown for ferrite in the RVE for the S-83 sample is ~500 MPa

Summary

Introduction

The critical factor in the exponential growth of the mobility, mechanization, and infrastructure sectors in the last six to seven decades is the improvement in the existing and development of novel steel materials [1]. About 1.8 billion tons of raw carbon steel is produced annually around the world. 5%) of steel are used by the automobile industry as a raw material in the form of different grades [1]. Better steels can improve fuel consumption, minimize the detrimental carbon footprint, and assist in making aesthetically lucrative vehicle body shapes, and increase collision safety. This motivates researchers and manufacturers to explore and use lightweight, highly deformable, and extended energy-absorbing steels in the front and rear sections of the vehicle body [3]

Results

Discussion

Conclusion