Fracture Mechanisms in Dual-Phase Steel: Influence of Martensite Volume Fraction and Ferrite Grain Size

Abstract The effect of the morphology and the martensite volume fraction on the microhardness, the tensile, the friction and the wear behavior of API X52 dual phase (DP) steel has been investigated. Three different heat treatments were used to develop dual phase steel with different morphologies and with different amounts of martensite: Intermediate Quenching Treatment/Water (IQ); Step Quenching Treatment (SQ) and direct quenching (DQ). Tribological tests are conducted on DP steels using a ball-on-disc configuration under normal load of 5 N and at a sliding speed of 4 cm/s were used to study the friction and wear behavior of treated samples. Results show that the ferrite–martensite morphology has a great influence on the mechanical properties of dual phase steel. The steel subjected to (IQ) treatment attain superior mechanical properties compared to the SQ and the DQ treatments. On the other hand, it is also found that the friction coefficient and the wear rate (volume loss) decrease when the hardness and the martensite volume fraction increase. The steel with fine fibrous martensite provide good wear resistance.

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Effect of Laminar Cooling Parameters on Martensite Volume Fraction and Mechanical Properties of Hot Rolled Dual Phase Steel

EPD Congress 2015 ◽

10.1002/9781119093503.ch15 ◽

2015 ◽

pp. 125-131

Author(s):

Sibel Daglılar ◽

Isıl Kerti ◽

Sinem Yıldırım

Keyword(s):

Mechanical Properties ◽

Dual Phase Steel ◽

Volume Fraction ◽

Dual Phase ◽

Laminar Cooling ◽

Martensite Volume Fraction ◽

Hot Rolled

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Micromechanical Simulation Approach of Dual Phase Steel Artificial Microstructure Using Random Field Model

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1016.534 ◽

2021 ◽

Vol 1016 ◽

pp. 534-540

Author(s):

Mohamed Imad Eddine Heddar ◽

Nadjoua Matougui ◽

Brahim Mehdi

Keyword(s):

Grain Size ◽

Random Field ◽

Dual Phase Steel ◽

Field Model ◽

Volume Fraction ◽

Gaussian Kernel ◽

Dual Phase ◽

Strain Behavior ◽

Proportional Relationship ◽

Dp Steels

In this study, a random field (RF) model with a Gaussian kernel was applied to generate an artificial microstructure of dual phase (DP) steels. Micrographs obtained from Scanning Electron Microscopy (SEM) were analyzed using image processing software to extract the grain size and the volume fraction of each phase. Based on watershed (Ws) segmentation and quantitative analysis, the real and artificial microstructures were compared by analyzing grain features related the solidity, grain size and aspect ratio (the proportional relationship between its width and its height). Consequently, this approach allows to simulate the overall stress-strain behavior of the analyzed microstructures. As a result, it was shown that the strain localization starts to develop at the ferrite/martensite interface and that the RF model could replicate the micromechanical behavior of DP steels.

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