Stress evolution in plastically deformed austenitic and ferritic steels determined using angle- and energy-dispersive diffraction

In the presented research, the intergranular elastic interaction and the second-order plastic incompatibility stress in textured ferritic and austenitic steels were investigated by means of diffraction. The lattice strains were measured inside the samples by the multiple reflection method using high energy X-rays diffraction during uniaxial in situ tensile tests. Comparing experiment with various models of intergranular interaction, it was found that the Eshelby-Kr\"oner model correctly approximates the X-ray stress factors (XSFs) for different reflections hkl and scattering vector orientations. The verified XSFs were used to investigate the evolution of the first and second-order stresses in both austenitic and ferritic steels. It was shown that considering only the elastic anisotropy, the non-linearity of $\sin^2{\psi}$ plots cannot be explained by crystallographic texture. Therefore, a more advanced method based on elastic-plastic self-consistent modeling (EPSC) is required for the analysis. Using such methodology the non-linearities of $\cos^2{\phi}$ plots were explained, and the evolutions of the first and second-order stresses were determined. It was found that plastic deformation of about 1- 2% can completely exchange the state of second-order plastic incompatibility stresses

Stress evolution in plastically deformed austenitic and ferritic steels determined using angle- and energy-dispersive diffraction

In the presented research, the intergranular elastic interaction and the second-order plastic incompatibility stress in textured ferritic and austenitic steels were investigated by means of diffraction. The lattice strains were measured inside the samples by the multiple reflection method using high energy X-rays diffraction during uniaxial in situ tensile tests. Comparing experiment with various models of intergranular interaction, it was found that the Eshelby-Kr¨oner model correctly approximates the X-ray stress factors (XSFs) for different reflections hkl and scattering vector orientations. The verified XSFs were used to investigate the evolution of the first and second-order stresses in both austenitic and ferritic steels. It was shown that considering only the elastic anisotropy, the non-linearity of sin2ψ plots cannot be explained by crystallographic texture. Therefore, a more advanced method based on elastic-plastic self-consistent modeling (EPSC) is required for the analysis. Using such methodology the non-linearities of cos2φ plots were explained, and the evolutions of the first and second-order stresses were determined. It was found that plastic deformation of about 1–2% can completely exchange the state of second-order plastic incompatibility stresses

Attempt to identify factors impacting preferences of young women for traditionally produced dark beer

Celem pracy było zidentyfikowanie czynników wpływających na preferencje młodych kobiet wobec piw ciemnych produkowanych metoda tradycyjną. Ocenie sensorycznej poddano tradycyjne piwa ciemne produkowane w polskich browarach. W badaniu zastosowano nieustrukturowaną skalę liniową, odmianę skali Likerta. Badania wykazały, że podstawowym czynnikiem wyboru piw ciemnych przez młode kobiety był smak słodki. W testach konsumenckich większość młodych kobiet nie akceptowała piwa o gorzkim smaku. Na wybór piwa nie miał wpływu zapach. Badania nie wykazały również wpływu opakowania na wybór piwa. Przeprowadzone badania wykazały, że ciemne piwa tradycyjne mogą stać się atrakcyjnym napojem niskoalkoholowym dla młodych kobiet z uwagi na wyjątkową smakowitość, determinowaną słodkim smakiem.The objective of the research was to identify factors impacting the preferences of young women for traditionally produced dark beer. Traditional dark beers produced in Polish breweries were sensory assessed. A non-structured linear scale (a variant of Likert scale) was used to perform the assessment. The research results showed that the sweet taste was the most important factor deciding that young women selected dark beers. The consumer tests proved that the majority of young women did not accept bitter- tasting beers. The beer's aroma did not affect the choice of beer. The research results did not show any impact of beer packaging on the choice either. The research performed proved that traditional dark beer could become an attractive low-alcohol beverage for young women owing to its exceptional tastiness attributed to its sweet taste

Neutron time-of-flight diffraction used to study aged duplex stainless steel at small and large deformation until sample fracture

Owing to its selectivity, diffraction is a powerful tool for analysing the mechanical behaviour of polycrystalline materials at the mesoscale (phase and/or grain scale). In situ neutron diffraction during tensile tests and elastoplastic self-consistent modelling were used to study slip phenomena occurring on crystallographic planes at small and large deformation. The critical resolved shear stresses in both phases of duplex stainless steel were found for samples subjected to different thermal treatments. The evolution of grain loading was also determined by showing the large differences between stress concentration for grains in ferritic and austenitic phases. It was found that, for small loads applied to the sample, linear elastic deformation occurs in both phases. When the load increases, austenite starts to deform plastically, while ferrite remains in the elastic range. Finally, both phases undergo plastic deformation until sample fracture. By using an original calibration of diffraction data, the range of the study was extended to large sample deformation. As a result, mechanical effects that can be attributed to damage processes initiated in ferrite were observed. © 2011, Wiley-Blackwell