Abstract
We evaluated the availability of an optical-microscopy-based damage quantification method in a ferrite/ martensite dual-phase steel, and interpreted the obtained results toward screening damage evolution behavior under various test conditions. In this study, we employed this method for tensile deformation at 20, −100, and −180°C to analyze the temperature dependence of damage evolution in cryogenic regime as a case study. The damage evolution behavior was classified into regimes of damage nucleation, damage arrest, and damage growth to fracture, irrespective of the deformation temperature in a cryogenic temperature range. Coupled with some high-resolution observations, the damage nucleation and damage arrest sites were identified to be martensite and ferrite, which are common regardless of the deformation temperatures. This indicates that ferrite acted as a damage arrest site even at −180°C. However, a critical strain for damage growth to fracture decreased drastically by decreasing the temperature to −180°C. The distinct reduction in the critical strain is attributed to the transition of ferrite cracking mode from ductile to brittle mechanisms.
Original language | English |
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Pages (from-to) | 179-185 |
Number of pages | 7 |
Journal | Isij International |
Volume | 58 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2018 |
Keywords
- Damage arrest
- Damage quantification
- Dual-phase steel
- Ferrite
- Low temperature
- Martensite cracking
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry