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The morphology of Ni4Ti3 precipitates is important in tuning the martensitic transformation (MT) behavior and mechanical properties of nitinol. Constrained ageing is effective in engineering the morphology of Ni4Ti3 precipitates due to the variant selection effect of external load which is still lacking. In this work, maps of variant selection effect of external load applied along all crystallographic directions are obtained by using a combination of theoretical analyses and phase field simulations. It is found that maps produced by uniaxial tension and uniaxial compression are quite different. The number and types of Ni4Ti3 variants preferred by external load vary as the loading direction changes. Moreover, factors influencing the strength of variant selection effect are discovered. This work provides insights on understanding the Ni4Ti3 precipitation process and sheds light on the engineering of morphology of Ni4Ti3 precipitates for desired mechanical and functional properties. (Figure presented.) © The Chinese Society of Theoretical and Applied Mechanics and Springer-Verlag GmbH Germany, part of Springer Nature 2024.

Heterogeneous systems, consisting of CPUs and GPUs, offer the capability to address the demands of compute- and data-intensive applications. However, programming such systems is challenging, requiring knowledge of various parallel programming frameworks. This paper introduces COMPAR, a component-based parallel programming framework that enables the exposure and selection of multiple implementation variants of components at runtime. The framework leverages compiler directive-based language extensions to annotate the source code and generate the necessary glue code for the StarPU runtime system. COMPAR provides a unified view of implementation variants and allows for intelligent selection based on runtime context. Our evaluation demonstrates the effectiveness of COMPAR through benchmark applications. The proposed approach simplifies heterogeneous parallel programming and promotes code reuse while achieving optimal performance. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

For polycrystalline materials, key material properties, such as mechanical anisotropy or transformation behavior, and magnetic properties strongly depend on the crystallographic texture of the crystalline material. Assessment of texture is generally destructive and highly local. Only high energy X-ray diffraction at synchrotron sources and neutrons enable to study, non-destructively, the microstructure in the bulk of materials. Here, we report how progress in Laue three-dimensional neutron diffraction tomography enables to index the crystallographic orientation of several hundred grains and, thus, enables grain-resolved characterization of texture in the volume of centimeter-sized coarse-grained samples with statistical significance. To demonstrate the neutron technique for characterizing the crystallographic microstructure, we investigate a Fe-Ni-Mn austenitic alloy. A total number of 481 grains within a 1 cm(3) of material is indexed and the results in assessing the crystallographic texture are compared with electron backscatter diffraction measurements. The short exposure times and non-destructive nature of the Laue three-dimensional neutron diffraction render it a novel promising method for corresponding characterization. (C) 2022 The Author(s). Published by Elsevier Ltd.

Periprosthetic joint infection (PJI) is a difficult complication requiring a comprehensive eradication protocol. Cure rates have essentially stalled in the last two decades, using methods of antimicrobial cement joint spacers and parenteral antimicrobial agents. Functional spacers with higher-dose antimicrobial-loaded cement and antimicrobial-loaded calcium sulphate beads have emphasized local antimicrobial delivery on the premise that high-dose local antimicrobial delivery will enhance eradication. However, with increasing antimicrobial pressures, microbiota have responded with adaptive mechanisms beyond traditional antimicrobial resistance genes. In this review we describe adaptive resistance mechanisms that are relevant to the treatment of PJI. Some mechanisms are well known, but others are new. The objective of this review is to inform clinicians of the known adaptive resistance mechanisms of microbes relevant to PJI. We also discuss the implications of these adaptive mechanisms in the future treatment of PJI. Cite this article: Bone Joint J 2022;104-B(5):575-580.

For polycrystalline materials, key material properties, such as mechanical anisotropy or transformation behavior, and magnetic properties strongly depend on the crystallographic texture of the crystalline material. Assessment of texture is generally destructive and highly local. Only high energy X-ray diffraction at synchrotron sources and neutrons enable to study, non-destructively, the microstructure in the bulk of materials. Here, we report how progress in Laue three-dimensional neutron diffraction tomography enables to index the crystallographic orientation of several hundred grains and, thus, enables grain-resolved characterization of texture in the volume of centimeter-sized coarse-grained samples with statistical significance. To demonstrate the neutron technique for characterizing the crystallographic microstructure, we investigate a Fe-Ni-Mn austenitic alloy. A total number of 481 grains within a 1 cm(3) of material is indexed and the results in assessing the crystallographic texture are compared with electron backscatter diffraction measurements. The short exposure times and non-destructive nature of the Laue three-dimensional neutron diffraction render it a novel promising method for corresponding characterization. (C) 2022 The Author(s). Published by Elsevier Ltd.

The mechanisms driving variant selection phenomena in ausformed bainitic microstructures are not fully controlled yet. Previous results are not congruent among them, as they cannot be explained by the same rule. In this work, we aimed to understand the mechanisms governing variant selection in a medium carbon-high silicon steel subjected to ausforming treatments. To do so, the microstructural characterization in different regions of barreled samples has been combined with the simulation of the stress and strain state at the macro and micro level, by finite elements simulations and crystal plasticity simulations, respectively. The main conclusion is that the variant selection shown in these microstructures can be explained by understanding the distribution of the plastic strains at the macro and micro level. The selection of crystallographic variants is more pronounced in the regions which have been more deformed. Also, the deformation distributes along deformation microbands, where the most promoted variants seem to grow, in good agreement with previous results in ausformed lath martensite., Team Jilt Sietsma

The wear resistance of the biomedical low-carbon Co-28Cr-6Mo (wt.-%) alloy is primarily determined by the onset and magnitude of the face-centered cubic to hexagonal close-packed deformation-induced martensitic phase transformation. In metal-on-metal joint bearings, local plastic deformation occurs on the surface and in the subsurface regions. This can cause deformation-assisted structural changes in the material, such as mechanical twinning and/or martensitic transformation. In the present work, we report the structural transition on the surface and bulk of a laser powder bed fusion additively manufactured Co-28Cr-6Mo alloy in response to an externally imposed load. This study was possible using in-situ synchrotron X-ray diffraction at two different energy levels. Our results revealed that from tensile deformation to fracture, the phase transformation kinetics and magnitude were marginally higher on the surface. During transformation, {200}FCC peak broadening was observed in the bulk and this was attributed to stacking fault accumulation., Peer Reviewed, Postprint (author's final draft)

The mechanisms driving variant selection phenomena in ausformed bainitic microstructures are not fully controlled yet. Previous results are not congruent among them, as they cannot be explained by the same rule. In this work, we aimed to understand the mechanisms governing variant selection in a medium carbon-high silicon steel subjected to ausforming treatments. To do so, the microstructural characterization in different regions of barreled samples has been combined with the simulation of the stress and strain state at the macro and micro level, by finite elements simulations and crystal plasticity simulations, respectively. The main conclusion is that the variant selection shown in these microstructures can be explained by understanding the distribution of the plastic strains at the macro and micro level. The selection of crystallographic variants is more pronounced in the regions which have been more deformed. Also, the deformation distributes along deformation microbands, where the most promoted variants seem to grow, in good agreement with previous results in ausformed lath martensite., Team Kevin Rossi

The selection of crystallographic variants in bainitic microstructures is a deeply studied topic which can be attributed to several reasons. In the cases where the prior austenite is textured, stressed or plastically deformed, the final ferrite texture and the dilatometry signal may change, being anisotropic. Although the causality between variant selection and the variation of the dilatometric signal has been previously assumed, it has not been thoroughly proved. In this work, the phenomenological theory of martensite was combined with a continuum mechanics analysis to calculate the relative length changes associated to the bainitic transformation during different bainitic transformations in order to prove the connection between the selection of crystallographic variants and the distortion of the dilatometry signal. To do so, four different bainitic microstructures were analyzed: one of them obtained by a pure isothermal treatment and the rest of them obtained by ausforming treatments. Some of the mentioned microstructures had shown to lead to negative longitudinal dilatometry signals and to present a strong variant selection. Results showed that the experimental trends could be explained by theoretical means, which enables to further understand the bainitic transformation.

Twining is an important deformation mode in magnesium. In a deformed magnesium sample, an extension twin crystal, i.e., {101¯2} twin, can form inside a {101¯2} primary twin, which is named {101¯2}–{101¯2} secondary twin. These secondary twins often appear at the intersection of two primary twins, and form primary–secondary twin pairs. Experimental observations show that the most frequently observed primary–secondary twin pairs have a unique misorientation, i.e., twin variant selection exists. Such variant selection of the primary–secondary twin pairs is studied in this work. The crystallographic analysis reveals that the twin planes of the primary and secondary twins that form a twin pair have coincident intersection lines with the boundary where the twin pair adjoins. An analytical calculation method based on Eshelby's inclusion theory is developed, and the calculation results show that only for this unique misorientation, the stress fields concentrated at the rims of the primary and the secondary twins are mutually favoured. The analysis is further extended to the incoming–outgoing twin pairs across ordinary grain boundaries, and compared with the commonly used geometrical compatibility factor m′. It is found that m′ only gives good prediction for twin transmission when the shear stress component on the twin plane along the twin shear direction of the incoming twin is the major contributor to the resolved shear stress of the outgoing twin. When other stress components play a dominant role, m′ becomes ineffective in prediction, which is the case for the primary–secondary twin pairs.

The mechanisms driving variant selection phenomena in ausformed bainitic microstructures are not fully controlled yet. Previous results are not congruent among them, as they cannot be explained by the same rule. In this work, we aimed to understand the mechanisms governing variant selection in a medium carbon-high silicon steel subjected to ausforming treatments. To do so, the microstructural characterization in different regions of barreled samples has been combined with the simulation of the stress and strain state at the macro and micro level, by finite elements simulations and crystal plasticity simulations, respectively. The main conclusion is that the variant selection shown in these microstructures can be explained by understanding the distribution of the plastic strains at the macro and micro level. The selection of crystallographic variants is more pronounced in the regions which have been more deformed. Also, the deformation distributes along deformation microbands, where the most promoted variants seem to grow, in good agreement with previous results in ausformed lath martensite.

Molecular dynamics simulations are used to study the effects of tensile loading on nucleation and subsequent growth of bcc phase in pure fcc iron. The results show that orientation variant selection occurs during the stress-induced fcc-to-bcc transformation, which leads to the coalescence of neighbouring bcc platelets with identical orientation. The bcc phase nucleates mainly following Nishiyama–Wassermann and Kurdjumov–Sachs orientation relationships with the parent fcc phase. The present simulations contribute to a better understanding of mechanisms controlling mechanically induced martensitic transformation as well as coalescence of bcc platelets in steels., Materials Science and Engineering, (OLD) MSE-3

Molecular dynamics simulations are used to study the effects of tensile loading on nucleation and subsequent growth of bcc phase in pure fcc iron. The results show that orientation variant selection occurs during the stress-induced fcc-to-bcc transformation, which leads to the coalescence of neighbouring bcc platelets with identical orientation. The bcc phase nucleates mainly following Nishiyama–Wassermann and Kurdjumov–Sachs orientation relationships with the parent fcc phase. The present simulations contribute to a better understanding of mechanisms controlling mechanically induced martensitic transformation as well as coalescence of bcc platelets in steels., Materials Science and Engineering, (OLD) MSE-3

The microstructure of martensite formed athermally or via deformation in Fe-Cr-Ni alloys with different austenite (gamma) stability has been investigated using microscopy. Two different types of microstructures, viz. blocky and banded structure, are observed after athermal and deformation-induced martensitic transformation (AMT and DIMT, respectively). The blocky structure form during AMT or DIMT if the stability of gamma is low. In both cases, there is a significant chemical driving force for the transformation from gamma to alpha'-martensite (alpha'), and if it is not hindered by e.g. planar defects it can grow uninhibited into a blocky morphology without the necessity to nucleate new crystallographic variants to accommodate the transformation strains. On the other hand, the banded structure is due to the formation of epsilon-martensite (epsilon) during AMT, or the wider concept shear bands in the case of DIMT. The shear bands, and in particular epsilon, lower the nucleation barrier for alpha' that forms within individual shear bands if the stability of gamma is low. Neighbouring alpha' units predominantly have a twin-related orientation relationship to accommodate the transformation strains. With increasing y stability during DIMT, variant selection becomes pronounced with preferred formation of variants favorable oriented with respect to the applied stress/strain field. The formation of alpha' at individual shear bands is also rare, since nos is present and instead alpha' forms at the intersection of shear bands for more stable gamma. In conclusion, AMT and DIMT for low gamma stability lead to similar microstructures, whereas the DIMT microstructure for high y stability is distinct., QC 20181002

In this study, digital image correlation was used for two widely different cases to assess the potential and the limitations of the technique for applications at high temperatures. Specifically, digital image correlation was employed in high-temperature low-cycle fatigue experiments in a nickel-based superalloy and in phase transformation experiments conducted on bainitic steel in order to shed light on the microstructural processes. Depending on the type of experiments, the microstructure was characterized prior to the experiments (fatigue) or after the experiments (phase transformation). In the fatigue experiments, it was found that the features dominating damage evolution were the dendrites resulting from the solidification of the cast material. In the phase transformation experiments, variant selection is active when stresses are superimposed during the phase transformation process, which resulted in the evolution of transformation plasticity strains. Thereby, mainly the bainite variants oriented along the [101], [201] and [121] directions were observed to grow parallel to the loading axis, which in turn led to transformation plasticity strains. For validation of the digital image correlation data, average strains were calculated for the surface area probed and compared to strain values obtained by conventional extensometry. In all cases studied, the correlation was satisfactory, indicating that digital image correlation can provide for additional insight into processes active at the micro level. © 2013 IMechE.

In this study, digital image correlation was used for two widely different cases to assess the potential and the limitations of the technique for applications at high temperatures. Specifically, digital image correlation was employed in high-temperature low-cycle fatigue experiments in a nickel-based superalloy and in phase transformation experiments conducted on bainitic steel in order to shed light on the microstructural processes. Depending on the type of experiments, the microstructure was characterized prior to the experiments (fatigue) or after the experiments (phase transformation). In the fatigue experiments, it was found that the features dominating damage evolution were the dendrites resulting from the solidification of the cast material. In the phase transformation experiments, variant selection is active when stresses are superimposed during the phase transformation process, which resulted in the evolution of transformation plasticity strains. Thereby, mainly the bainite variants oriented along the [101], [201] and [121] directions were observed to grow parallel to the loading axis, which in turn led to transformation plasticity strains. For validation of the digital image correlation data, average strains were calculated for the surface area probed and compared to strain values obtained by conventional extensometry. In all cases studied, the correlation was satisfactory, indicating that digital image correlation can provide for additional insight into processes active at the micro level. © 2013 IMechE.

There has recently been significant interest in the problem of variant selection in the strain-induced transformation of austenite to α'-martensite in metastable austenitic stainless steels. Previous work has highlighted our poor understanding of the mechanisms leading to this transformation, in particular the role that the macroscopic stress plays in the transformation. In this work, we have sought to perform detailed experiments aimed at developing a statistical grain level view of variant selection in one particular grade of austenitic stainless steel. EBSD measurements made over a large number of grains as well as macroscopic texture measurements made at different levels of imposed plastic strain allow for comparison against various approaches for predicting variant selection based on the Patel-Cohen interaction energy. © (2012) Trans Tech Publications, Switzerland., SCOPUS: cp.k, info:eu-repo/semantics/published

Samples of the magnesium alloy AZ31 have been deformed by compression to strains of 5% and 10% and microstructural observations made to investigate the activation of specific {1 0 1¯ 2} extension twin variants. The twinning has been analyzed on a grain-by-grain basis for more than 260 grains to determine both the number of extension twin variants in each grain, and the volume fraction of each. At 5% strain approx. 30% of the grains contain twins corresponding to variants with the third or lower ranked Schmid factor, with the fraction increasing to 40% after 10% compression. A grain size effect is also observed in that smaller grains are less likely to contain lower ranked twin variants. For both 5% and 10% compression no clear relationship exists between the volume fraction of each twin variant in a given grain population and the Schmid factor for the twin variant. A positive linear relationship can be defined, however, between the maximum twinning fraction that a twin variant can reach and its Schmid factor.

Samples of the magnesium alloy AZ31 have been deformed by compression to strains of 5% and 10% and microstructural observations made to investigate the activation of specific {1 0 1¯ 2} extension twin variants. The twinning has been analyzed on a grain-by-grain basis for more than 260 grains to determine both the number of extension twin variants in each grain, and the volume fraction of each. At 5% strain approx. 30% of the grains contain twins corresponding to variants with the third or lower ranked Schmid factor, with the fraction increasing to 40% after 10% compression. A grain size effect is also observed in that smaller grains are less likely to contain lower ranked twin variants. For both 5% and 10% compression no clear relationship exists between the volume fraction of each twin variant in a given grain population and the Schmid factor for the twin variant. A positive linear relationship can be defined, however, between the maximum twinning fraction that a twin variant can reach and its Schmid factor.

Austenitic steels can exhibit a complex transformation sequence during deformation. Indeed, the austenitic phase transforms first into bands of ε (HCP) martensite. This transformation is then followed by the formation of α' (BCC) martensite. In this study, the crystallography of the transformation together with the occurrence of variant selection is studied at the scale of individual austenite grains. About ten prior austenite grains deformed at different strain levels in uniaxial tension were analysed by means of EBSD techniques. One of the classical approaches to predict the variant selection phenomenon is based on the calculation of the interaction energy between the macroscopic stress and the shape deformation associated with the formation of the product phase. The formation of the α' variants was observed to lead to a very strong variant selection that cannot be fully explained by energetic criterion. It is suggested that the crystallography of the transformation sequence can account for the unexpected variants. © (2011) Trans Tech Publications., SCOPUS: cp.k, info:eu-repo/semantics/published

The variant selection phenomenon during the austenite to bainite phase transformation in hot-rolled TRIP-aided steels was quantitatively characterized at the level of individual austenite grains. The reconstruction of the electron backscatter diffraction maps provided evidence that bainite grows by packets of laths sharing a common {1 1 1}γ plane in the austenite. The affect of hot deformation is to reduce the number of packets that form. It is suggested that slip activity is important in understanding this effect. © 2009 Acta Materialia Inc., SCOPUS: ar.j, info:eu-repo/semantics/published

The variant selection phenomenon during the austenite to bainite phase transformation in hot-rolled TRIP-aided steels was quantitatively characterized at the level of individual austenite grains. The reconstruction of the electron backscatter diffraction maps provided evidence that bainite grows by packets of laths sharing a common {1 1 1}(gamma) plane in the austenite. The affect of hot deformation is to reduce the number of packets that form. It is suggested that slip activity is important in understanding this effect. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

The potential for decreasing the texture intensity generated during the bulk deformation of Mg alloys was investigated using a combination of contraction twinning, double (secondary) twinning and static recrystallization. A large number of twins was induced by tensile deformation at room temperature. Their volume fraction and the variants selected during straining were found to be largely responsible for the changes evident in the deformation texture. Recrystallization of the twins generated a fine-grained microstruc-ture, although no growth into the matrix grains was observed. In this way, annealing of the deformed samples did not lead to significant further texture changes. © Carl Hanser Verlag GmbH & Co. KG., SCOPUS: ar.j, info:eu-repo/semantics/published

A 0.79C-1.5Si-1.98Mn-0.98Cr-0.24Mo-1.06Al-1.58Co (wt%) steel was isothermally heat treated at 200 and 350°C bainitic transformation temperatures. The microstructure was consisted of bainitic ferrite lath and retained austenite for both heat treatment conditions. The crystallographic analysis revealed that the bainitic ferrite laths are close to the Nishiyama-Wassermann orientation relationship with their parent austenite. The isothermal bainite transformation temperature has a significant effect on the retained austenite characteristics and the variant selection of the bainitic ferrite laths. In general, a decrease in the isothennal bainite transformation temperature refined the bainitic structure and weakened the variant selection.

Texture development during the subtransus hot forging of alpha/beta titanium alloys with an equiaxed-alpha microstructure was modeled using the Los Alamos Polycrystalline Plasticity (LApp) code and <111> pencil-glide polycrystalline plasticity code coupled with the finite-element-method (FEM) program DEFORM. The methodology treated the partitioning of the imposed strain between the alpha and beta phases, and thus enabled the prediction of the distinct deformation textures developed in the primary alpha and beta matrix during hot working. Two variant selection rules in conjunction with the beta deformation texture were also examined to establish a method for predicting the transformation texture of secondary alpha developed as a result of beta decomposition during cool-down following forging or heat treatment. The approach was validated via an industrial-scale trail comprising hot pancake forging of Ti-6Al-4V., Work unit no. M02R2000 Prepared in collaboration with Rolls-Royce Corporation, Indianpolis, IN., General Electric Aviation, Cincinnati, OH., Air Force Reseach Laboratory, Wright-Patterson AFB, OH.

The microstructures of TRIP steels finish-rolled above and below the recrystallization-stop temperature (T-nr) are compared. Here, the retained austenite grains are equiaxed or elongated, respectively, according to whether final rolling was carried out above or below the Tnr. The recrystallized austenite did not contain a sharp texture, the best defined component of which was the cube. The bainite that formed in this case was characterized by weak concentrations of the Goss and rotated Goss and a fairly strong concentration of the rotated cube. It also displayed the transformation products of a retained rolling fibre in the prior austenite. The deformed austenite contained the typical fcc rolling texture, where the copper is considerably more intense than the brass under these conditions. After transformation to bainite, the presence of a strong transformed copper component is evident, together with somewhat less intense contributions from the three transformed brass components. The data indicate that strong variant selection took place in the deformed austenite and that it was also present in the recrystallized material, but to a lesser extent. The latter displayed evidence of incomplete recrystallization in that the transformation texture included components obtained from both "recrystallized" and "deformed" austenite., FLWNA, SCOPUS: ar.j, info:eu-repo/semantics/published

The microstructures of TRIP steels finish-rolled above and below the recrystallization-stop temperature (T-nr) are compared. Here, the retained austenite grains are equiaxed or elongated, respectively, according to whether final rolling was carried out above or below the Tnr. The recrystallized austenite did not contain a sharp texture, the best defined component of which was the cube. The bainite that formed in this case was characterized by weak concentrations of the Goss and rotated Goss and a fairly strong concentration of the rotated cube. It also displayed the transformation products of a retained rolling fibre in the prior austenite. The deformed austenite contained the typical fcc rolling texture, where the copper is considerably more intense than the brass under these conditions. After transformation to bainite, the presence of a strong transformed copper component is evident, together with somewhat less intense contributions from the three transformed brass components. The data indicate that strong variant selection took place in the deformed austenite and that it was also present in the recrystallized material, but to a lesser extent. The latter displayed evidence of incomplete recrystallization in that the transformation texture included components obtained from both "recrystallized" and "deformed" austenite., FLWNA, SCOPUS: ar.j, info:eu-repo/semantics/published

The mechanisms governing the formation of transformation textures during the austenite-to-ferrite transformation are the subject of major debate. In this study, two extreme cases were examined: those of undeformed and deformed austenite. The first involves the transformation of austenite into Widmanstatten ferrite under "equilibrium" conditions in the Gibeon iron-nickel meteorite. This meteorite passed through the transformation at the rate of a few degrees per million years. Such cooling rates cannot of course be reached under laboratory conditions. The second concerns the transformation of hot rolled austenite after a quench into the bainite temperature range. These two behaviors were investigated by means of optical microscopy and electron backscatter diffraction (EBSD) techniques. The orientations of both the parent and product phases were measured and the orientation relationships are represented in Rodrigues-Frank (R-F) space. From the orientation of a particular FCC crystal, the crystallographic orientations of the product BCC crystals can be predicted according to the Bain, Kurdjumov-Sachs (K-S) and Nishiyama-Wassermann (N-W) correspondence relationships. Comparison of the predicted and measured orientations reveals that the Bain rotation is never observed; the K-S and N-W relationships are both observed and there is a continuous distribution of orientations between the exact K-S and N-W positions. The formation of preferred orientations under non-equilibrium conditions is scrutinized. These results are compared to recent models accounting for variant selection.

The crystallographic relationship between the gamma and alpha phases in samples of the Gibeon meteorite and a TRIP steel was investigated by means of EBSD techniques. The orientations of the two phases were measured and are represented in pole figures. The results are compared to predictions made on the basis of the Bain, Kurdjumov-Sachs (K-S), Nishiyama-Wassermann (NW), Greninger-Troiano (G-T) and Pitsch orientation relationships. The local misorientation between individual fcc and bcc crystals along their common interface was measured to demonstrate the way in which the exact orientation relationship varies along the boundary. The local orientations within lamellae and laths of kamacite and bainite are compared to that in recrystallised ferrite polygons. The occurrence of variant selection during the transformation of deformed austenite is analyzed using a recent dislocation-based model.

The transformation behavior of a 0.22wt%C-1.50wt%Mn-1.56wt%Si-0.045wt%Nb steel was studied after controlled rolling. Deformation below the no-recrystallisation temperature was employed to deform the prior austenite. During bainitic holding, some of the austenite was retained due to the enrichment of carbon in this phase. Using automated EBSD techniques, both the retained austenite and bainite orientations were measured and the orientation relationships between these phases are represented in Rodrigues-Frank space. The specific orientations predicted by the Bain, Kurdjumov-Sachs and Nishiyama-Wassermann relationships are compared with the measurements and the occurrence of variant selection is discussed.