scholarly journals Geometrically Necessary Dislocations on Plastic Deformation of Polycrystalline TRIP Steel

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 289 ◽  
Author(s):  
Joan Josep Roa ◽  
Sebastián Suárez ◽  
Agustina Guitar ◽  
Gemma Fargas ◽  
Antonio Mateo
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Deformation Mechanism ◽  
Trip Steel ◽  
Deformation Behavior ◽  
Local Level ◽  
Length Scale ◽  
Transformation Induced Plasticity ◽  
Sharp Indentation ◽  
Main Deformation

In this study, the main deformation behavior in terms of geometrically necessary dislocations (GND) was investigated on a transformation induced plasticity (TRIP) stainless steel by using sharp indentation at nanometric length scale. Results evidence that austenitic grains display an isotropic behavior on terms of GND, the main deformation mechanism being the Frank–Read source activated at local level.

scholarly journals Molecular Dynamics as a Means to Investigate Grain Size and Strain Rate Effect on Plastic Deformation of 316 L Nanocrystalline Stainless-Steel

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3223 ◽  
Author(s):  
Abdelrahim Husain ◽  
Peiqing La ◽  
Yue Hongzheng ◽  
Sheng Jie
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Stainless Steel ◽  
Grain Boundary ◽  
Strain Rate ◽  
Deformation Mechanism ◽  
Grain Boundary Sliding ◽  
Plastic Deformation Mechanism ◽  
Grain Sizes ◽  
Critical Grain Size

In the present study, molecular dynamics simulations were employed to investigate the effect of strain rate on the plastic deformation mechanism of nanocrystalline 316 L stainless-steel, wherein there was an average grain of 2.5–11.5 nm at room temperature. The results showed that the critical grain size was 7.7 nm. Below critical grain size, grain boundary activation was dominant (i.e., grain boundary sliding and grain rotation). Above critical grain size, dislocation activities were dominant. There was a slight effect that occurred during the plastic deformation mechanism transition from dislocation-based plasticity to grain boundaries, as a result of the stress rate on larger grain sizes. There was also a greater sensitive on the strain rate for smaller grain sizes than the larger grain sizes. We chose samples of 316 L nanocrystalline stainless-steel with mean grain sizes of 2.5, 4.1, and 9.9 nm. The values of strain rate sensitivity were 0.19, 0.22, and 0.14, respectively. These values indicated that small grain sizes in the plastic deformation mechanism, such as grain boundary sliding and grain boundary rotation, were sensitive to strain rates bigger than those of the larger grain sizes. We found that the stacking fault was formed by partial dislocation in all samples. These stacking faults were obstacles to partial dislocation emission in more sensitive stress rates. Additionally, the results showed that mechanical properties such as yield stress and flow stress increased by increasing the strain rate.

Analysis of Rheological Behavior on Transformation Induced Plasticity Steel

2016 ◽  
Vol 850 ◽  
pp. 120-127
Author(s):  
Ji Quan Sun ◽  
Sheng Yang Teng ◽  
Yan Jun Yin ◽  
Chuang Niu
Keyword(s):  
Plastic Deformation ◽  
Trip Steel ◽  
Test Machine ◽  
Transformation Induced Plasticity ◽  
Shaping Time ◽  
Plastic Forming ◽  
Plastic Shaping ◽  
Simulated Test ◽  
Plastic Deformation Rate ◽  
Gleeble 3500

The cupping tests under different rate demonstrated that there was a correlation between the plastic deformation and shaping time of transformation induced plasticity (TRIP) steel, illustrating that there was also the rheology in the process of plastic forming for solid metal materials. The creep experiments were carried out by Gleeble 3500 thermal simulated test machine, and Mises yield rule was used to verify the creep experiments satisfying the visco-plastic conditions when the load was greater than yield strength. The visco-plastic deformation rate of creep experiments was obtained based on Bingham model. The viscous correlation coefficient (γ) was deduced, reaching that the viscosity of TRIP steel shows deformation resistance in the process of plastic shaping. These results provide the theoretical basis for increasing the plate yield and controlling the forming rate.

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