Quantitative Estimation of the Second Order Plastic Incompatibility Stresses in Textured Duplex Steel

A new method for determining the parameters characterising elastoplastic deformation of two-phase material is proposed. The method is based on the results of neutron diffraction, which are analysed using the self-consistent rate-independent model of elastoplastic deformation. The neutron diffraction method (time-of-flight technique) was applied and the self-consistent model was used to predict the second order stresses in austeno-ferritic duplex steel. Calculations based on the model were successfully compared with experimental results for both phases of the duplex steel.

Download Full-text

Quantitative estimation of incompatibility stresses and elastic energy stored in ferritic steel

Journal of Applied Crystallography ◽

10.1107/s0021889808023911 ◽

2008 ◽

Vol 41 (5) ◽

pp. 854-867 ◽

Cited By ~ 37

Author(s):

A. Baczmanski ◽

P. Lipinski ◽

A. Tidu ◽

K. Wierzbanowski ◽

B. Pathiraj

Keyword(s):

Elastic Energy ◽

Ferritic Steel ◽

Quantitative Estimation ◽

Second Order ◽

The Self ◽

X Ray Diffraction ◽

Near Surface ◽

Consistent Model ◽

Self Consistent ◽

Euler Space

Plastic incompatibility second-order stresses were determined for different orientations of a polycrystalline grain, using X-ray diffraction data and results of the self-consistent elasto-plastic model. The stresses in cold rolled ferritic steel were determined both in as-received and under tensile loaded conditions. It has been shown that the Reuss model and the self-consistent model applied to near surface volume provide the best approaches to determine diffraction elastic constants. For the first time, the elastic energy in an anisotropic material (arising from plastic incompatibilities between grains having various lattice orientations) has been determined. The second-order incompatibility stresses and stored elastic energy are presented in Euler space.

Download Full-text

Localization of Stresses in Polycrystalline Grains Measured by Neutron Diffraction and Predicted by Self-Consistent Model

Materials Science Forum ◽

10.4028/www.scientific.net/msf.681.103 ◽

2011 ◽

Vol 681 ◽

pp. 103-108

Author(s):

Anita Gaj ◽

Lea le Joncour ◽

Andrzej Baczmanski ◽

Sebastian Wroński ◽

Benoit Panicaud ◽

...

Keyword(s):

Neutron Diffraction ◽

Load Transfer ◽

Diffraction Method ◽

Lattice Strains ◽

Consistent Model ◽

Self Consistent ◽

Main Component ◽

Critical Resolved Shear Stress ◽

Elastic Lattice

Time of flight neutron diffraction method was applied to measure elastic lattice strains in austenitic steel during "in situ" tensile test. Comparing experimental data with self-consistent model, the critical resolved shear stress and hardening parameters were determined for polycrystalline grains. The result allowed us to determine the main component of the stress localization tensor, relating the rate of grain stress with the applied macrostress rate. The evolution of concentration tensor in function of the applied macrostress was analyzed. Finally, the load transfer between grains during yielding of the sample was studied.

Download Full-text

Neutron Diffraction Study of Duplex Stainless Steel during Loading at 200°C

Materials Science Forum ◽

10.4028/www.scientific.net/msf.571-572.175 ◽

2008 ◽

Vol 571-572 ◽

pp. 175-180

Author(s):

Rim Dakhlaoui ◽

Andrzej Baczmanski ◽

Chedly Braham ◽

Sebastian Wroński ◽

Krzysztof Wierzbanowski ◽

...

Keyword(s):

Neutron Diffraction ◽

Room Temperature ◽

Compressive Loading ◽

Diffraction Method ◽

Neutron Diffraction Study ◽

Shear Stresses ◽

Duplex Steel ◽

Consistent Model ◽

Influence Of Temperature On ◽

Tension And Compression

In this work, the influence of temperature on the mechanical properties of duplex steel is studied by performing monotonic “in situ” tension and compression at 200oC. The lattice strains in both phases were measured using the time-of-flight neutron diffraction method (at the ISIS spallation neutron source, STFC Rutherford Appleton Laboratory, UK). A thermal-elastic selfconsistent model was used to predict the expansion of the interplanar spacings during heating to 200°C. Subsequently, the variation of phase stresses during tensile and compressive loading at room temperature (20°C) and at 200°C were theoretically calculated by the elastoplastic self-consistent model. Comparing the model data with experimental results the critical resolved shear stresses and work hardening parameters were determined individually in each phase of the DSS. Finally, the yield stresses in each phase of the studied steel have been estimated. It was found that both yield points (of austenite and ferrite) are lower at 200°C than those at room temperature.

Download Full-text