Effects of Sample Geometry and Loading Rate onTensile Ductility of TRIP800 Steel

Journal Article · Sun Apr 15 00:00:00 EDT 2012 · Materials Science and Engineering. A. Structural Materials: Properties, Microstructure and Processing

DOI:https://doi.org/10.1016/j.msea.2011.12.115· OSTI ID:1042540

Sun, Xin; Soulami, Ayoub; Choi, Kyoo Sil; Guzman, O; Chen, Weinong W

The effects of sample geometry and loading rate on the tensile ductility of a commercial grade Transformation Induced Plasticity (TRIP) steel are examined in this paper. Quasistatic tensile tests were performed for the 1.2mm gauge TRIP800 steel sheets with two geometries: sub-sized ASTM E-8 and a custom designed miniature tensile sample. Sample geometry effects on post-uniform elongation are discussed together with other experimental data reported in the open literature. Further discussions on the effects of sample geometry are cast in the context of mesh-size dependent ductility in finite element-based engineering simulations. The quasi-static tensile curve for the miniature sample is then compared with the split Hopkinson bar results at the loading rates of 1700-S-1 and 2650-S-1 with the same sample design. In contrary to the typical strain rate sensitivity results for mild steel where the dynamic strength increase at high strain rate usually occurs at the price of ductility reduction, our results show that the TRIP800 under examination has positive strain rate sensitivity on both strength and ductility. Images of the deformation process captured by high speed camera together with scanning electron microscopy (SEM) near the fracture zone are also used to elucidate the different deformation modes at different loading rates.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1042540
• Report Number(s): PNNL-SA-85308; VT0505000; TRN: US201212%%825
• Journal Information: Materials Science and Engineering. A. Structural Materials: Properties, Microstructure and Processing, Vol. 541
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CAMERAS
DEFORMATION
DESIGN
DUCTILITY
ELONGATION
FRACTURES
GEOMETRY
LOADING RATE
PLASTICITY
PRICES
SCANNING ELECTRON MICROSCOPY
SENSITIVITY
STEELS
STRAIN RATE
TRANSFORMATIONS
VELOCITY
TRIP steels
strength
ductility
necking
localization
quasi-static tensile test
Dynamic tensile test