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The grain scale dynamic interaction of dislocations with the deformation induced martensites and twins, improving the strength, ductility and formability, in 304 LN austenitic stainless steel was examined at 28 and 350 °C through microstructure mapping using electron back scatter diffraction (EBSD) and electron channeling contrast imaging (ECCI) during interrupted tensile tests. Greater deformation induced martensites and twins form at 28 than 350 °C in the grains having higher Schmid factors. The larger geometrically necessary dislocation (GND) density, measured by EBSD, validates the excellent balance of strength and ductility at 28 than 350 °C. The rate of increase of GND density with strains and temperatures is not singular and can be explained by higher strain hardening, low dislocation cross-slip and dynamic recovery. The heterogeneity in GND distribution is greater at 28 °C due to presence of martensite, twins, refinement of the co-planar slip band spacings and formation of shear bands, fragmenting the grains with strains improving the work hardening. Finer austenite grains sustain larger GND density with temperatures and strains. Thus, GNDs are responsible for forest hardening (dissipative strain gradient strengthening) and generation of back stress (energetic strengthening) more at 28 than at 350 °C. [ABSTRACT FROM AUTHOR]

Surface mechanical treatments are known to introduce deformation heterogeneity, thus entailing a combination of excellent strength and ductility in metallic metals. Accumulative skin pass rolling (ASPR) was employed to introduce heterogeneous structure in pure copper, which significantly improved yield strength and maintained high ductility. The experimental observations of the ASPR processed copper showed that surface grains possessed a much larger magnitude of misorientations and geometrically necessary dislocations (GNDs) than the centre grains. Crystal plasticity finite element modelling was utilised to provide an in-depth understanding of microstructure evolution during ASPR. It was found that the surface grains accommodated higher shear strain and had higher slip resistance than the centre grains. The multiple active slip systems in the surface grains induce the lattice rotations and then the formation of intragranular misorientations accompanied by a high density of GNDs, while the single active slip system in the centre grains can accommodate the applied material rotation without the lattice rotation.

The defect of mixed-grain structure with millimeter-grade coarse grains (MCGs) is frequently found in heavy forgings, such as nuclear main pipes manufactured from 316LN steel. Renovation of such kind forgings can only be conducted through recrystallization. However, the allowed deformation is limited because the geometric size of forgings should be maintained during the renovation. For this purpose, the deformation heterogeneity of 316LN steel with mixed-grain structures were studied experimentally, which demonstrated that the MCGs were more inclined to deform than fine grains even if MCGs are with hard orientations. Therefore, a two-stage method was studied to refine MCGs, which takes the advantage of this deformation heterogeneity. The first stage was to impose a limited deformation to the steel at room temperature, suppressing the dynamic recovery and leading the preferentially deformed MCGs to accumulate enough deformation energy storage. The second stage was rapidly heating the deformed materials to realize static recrystallization (SRX). The results showed that the MCGs were completely refined by SRX even if the reduction rate is only 8%. The SRX mechanisms and refining assessments of MCGs under different deformation conditions were discussed. This work, thus, provides an effective method to salvage the heavy structures in engineering.

This study investigates heterogeneity in the deformation of an annealed sheet of commercially pure titanium (cp-Ti), its variation with loading direction and its influence on dwell fatigue response. Cp-Ti sheet with a typical cold rolling texture was deformed, along its rolling direction (RD) and transverse direction (TD), to the same strain level in tension. Higher level of grain boundary sliding in TD led to increased surface roughness (30% higher) in TD when compared to RD. Whereas, the higher extent of grain boundary-affected zones in TD resulted in a higher level of strain gradient, as evident from higher Kernal Average Misorientation values observed in TD. The reason for the higher extent of grain boundary sliding and formation of grain boundary-affected zones in TD samples was higher compatibility issues in TD. This work proposes a criterion defining the compatibility of a boundary. This criterion, which is based on the c-axis deviation of constituent grains with respect to the loading axis and the geometric compatibility of slip systems, is demonstrated to define the compatibility of a boundary completely. Using this criterion, a higher fraction of incompatible boundaries is identified in TD. Moreover, the markedly superior dwell fatigue response of RD samples when compared to TD is partly attributed to the lower heterogeneity in the nature of deformation in the former. Furthermore, textures with less damage prone grain boundaries and hence better dwell fatigue resistance is also proposed. Taken together, the present work underlines the principal role of crystallographic texture on the mechanical behaviour in general and dwell fatigue in particular. [ABSTRACT FROM AUTHOR]

Dynamic (up to 5500 s−1) and quasi-static compression tests are conducted on a 15 wt% B 4 C particle-reinforced Al (B 4 C/Al) composite. In situ , high-speed synchrotron X-ray phase contrast imaging and digital image correlation are employed to map mesoscale deformation fields at μm and μs scales. The bulk stress–strain curves show significant strain and strain-rate hardening under dynamic compression. The strain-rate sensitivity exponent is an order of magnitude higher at high strain rates (> 10 3 s−1) than that at low strain rates (< 10 − 2 s−1). Strain field mapping demonstrates distinct compressive strain localizations for both quasi-static and dynamic loading. Nevertheless, compressive strain localizations appear denser in spacing under dynamic loading, owing to spontaneous dislocation nucleation in both weak and strong zones. This results in a higher density of geometrically necessary dislocations, which contributes to the higher strain and strain-rate hardening of B 4 C/Al under dynamic loading. The ratio of the maximum local strain to the bulk average is ~ 1.5, and the local strain-rate enhancement cannot explain the increased rate sensitivity of B 4 C/Al under dynamic loading. Therefore, the rate-dependent deformation heterogeneity dominates the strain-rate hardening of B 4 C/Al. Postmortem analyses help correlate deformation features to particle- and grain-scale microstructures, yielding consistent results with mesoscale strain fields. [ABSTRACT FROM AUTHOR]

• One-layer RVE generated directly using EBSD increases simulation efficacy. • Geometrical deployment of martensite hinders ferrite stretch and localize strain. • Mobile dislocation density evolution causes stress and strain heterogeneity in ferrite. • Misorientation of ferrite grains are highly loading dependent. • Martensite vicinity intensifies dislocation interactions and evolution in ferrite. In this study, we employ a physics-based crystal plasticity finite element method (CPFEM) approach to study the microstructural response of DP600 steel to various loading types. With the pursued approach, it is possible link microstructural changes in the dual phase (DP) steel to its macroscopic response in a convenient and efficient manner. Microstructural data were acquired first from experimental work via the electron backscattered diffraction (EBSD) method. DP crystallographic features were then fed to a numerical hybrid calculation subroutine combining a comprehensive physics-based crystal plasticity scheme for ferrite along with an isotropic plasticity scheme for martensite defined on a single-layer representative volume element (RVE). The developed single-layer 3D mode, while allowing for high computational efficiency, can capture the stress/strain distribution, revealing the microscopic features of the deformation process including the physical evolution of the dislocation density, retexturing, and morphology. The single-layer RVE physics-based method employed herein establishes the strong correlation between morphology, dislocation density and deformation response of the material under various loading types. Specifically, findings reveal that the tendency of the ferrite phase neighboring the martensite regions in the DP steel to retexture is much more profound than pure ferrite when subjected to the same loading conditions, pointing out to the steep strain gradients in the former component. Martensite phase facilitates considerable heterogeneity in the stress and strain distribution, increases the misorientation polarization as well as leading to local strain hardening in the neighboring ferrite volume that stem from profound increase in spatial dislocation density. Stress-strain curves under various loading schemes are simulated and discussed in the light of the experimental findings in literature, revealing the dependence of the microstructural evolution on the loading type. [Display omitted] [ABSTRACT FROM AUTHOR]

The influence of pre-strain on the formation of bimodal grain structures and tensile properties of a Co–20Cr–15W–10Ni alloy was investigated. The bimodal grain structures consist of fine grains (FGs; 2–3 μm in diameter) and coarse grains (CGs; 8–16 μm in diameter), which can be manipulated by changing the pre-strain (ɛ = 0.3–0.7) and annealing temperatures (1000–1100 °C). High pre-strain applied in the samples can intensify the plasticity heterogeneity through increasing the total dislocation density and the local volumes of high-density dislocations. This can essentially result in finer FGs, a higher FG volume fraction, and overall grain refinement in the samples after annealing. High-temperature essentially increases both the size and volume fraction of CGs, leading to an increase in the average grain size. The tensile test suggests that the bimodal grain structured samples exhibited both high strength and ductility, yield strengths of 621–877 MPa and ultimate tensile strengths of 1187–1367 MPa with uniform elongations of 55.0%–71.4%. The superior strength-ductility combination of the samples arises from the specific deformation mechanisms of the bimodal grain structures. The tensile properties strongly depend on the size ratio and volume fraction of FGs/CGs in addition to the average grain size in the bimodal grain structures. The grain structures can be modified via changing the pre-strain and annealing temperature. [ABSTRACT FROM AUTHOR]

The effect of grain size on micro-void evolution and further macroscopic fracture in an austenite steel 316LN was studied through a series of experiments together with the full-field crystal plasticity finite element method (CPFEM) simulations. To probe the grain size effect on void behaviors, macroscopic tensile tests and microscopic fractography characterizations were conducted for samples with different grain sizes. A hierarchy modeling approach based on CPFEM was adopted to quantify the gran size effect accordingly. Authentic boundary conditions were enforced on the high-resolved representative volume elements (RVEs) with realistic grain structures and voids. The simulation results demonstrate that the deformation heterogeneity and the scatter of void growth increase with grain size. Via the quantitative analysis of the void dimension, an extended void growth model involving the effect of grain size was proposed on the basis of the Rice and Tracey model. The extended model adopts the Gaussian distribution to describe the non-uniform void growth induced by the grain-scale deformation heterogeneity and manifests the increase of void size deviation with grain size. The variation of void growth with grain size further leads to a transition of fracture modes. For the fine grain sample, coalescence of densely distributed voids dominates the fracture initiation, and the total void volume fraction thus plays a key role; For the coarse grain sample, however, the growth and coalescence of individual large void are critical for fracture occurrence. With the grain size affected void behavior, the ductility of the material is also shown to be grain size dependent. This study thus advances the comprehensive understanding of the micro-mechanics of ductile fracture and the relationship between microstructure and the macroscopic fracture behavior. • Identify the grain size effect on void behavior via experiments and full-field CP modeling. • Deformation and void size distribution become more uneven as grain size is increased. • An extended void growth model involving the effect of grain size was proposed. • Explain different ductile fracture mechanisms related to grain size. • Identify the relationship between ductility and grain size. [ABSTRACT FROM AUTHOR]

The quasi-static and dynamic deformation behaviours of high-pressure die-casting (HPDC) Al7Si0.2 Mg alloy were studied in this work. Competing effects among porosities, α-Al(Fe/Mn)Si phase, eutectic phase and α-Al dendrites on strain concentration and crack propagation at different strain rates were investigated using X-ray computed tomography (CT), scanning electron microscopy (SEM), in-situ electron backscattering diffraction (EBSD), and high-resolution digital image correlation (HR-DIC). The results indicate that yield strength and ductility of Al7Si0.2 Mg alloy were improved at high strain rates compare to quasi-static loading. Weak zones, including porosities and particle interfaces, primarily contributed to deformation heterogeneity under quasi-static tension, whereas both weak zones and Al matrix played a role under dynamic loading. Moreover, crack propagation was hardly observed on porosities during dynamic deformation, thereby reducing the sensitivity of ductility to porosity. The slip and rotation of α-Al dendrites became more pronounced during dynamic deformation. As a result, the area fraction of fractured eutectic phase increased dramatically and surpassed the area fraction of α-Al(Fe/Mn)Si phase, which became the dominant factor of crack propagation during dynamic deformation. [ABSTRACT FROM AUTHOR]

Microstructure-based numerical modeling of ferrite recrystallization in a cold-rolled dual-phase (DP) steel during continuous annealing has been performed by considering the deformation heterogeneity with a coupled simulation method. The plastic deformation inside the two-phase structures is firstly simulated using the crystal plasticity finite element method (CPFEM) at the grain scale with the initial grain structures and crystallographic orientations inputted from EBSD maps based on a digital material representation algorithm. The predicted local stored deformation energy is then incorporated into the cellular automaton model as the driving force for subsequent ferrite recrystallization nucleation and growth. The simulations demonstrate inhomogeneous microstructural behaviors of ferrite recrystallization owing to the microstructural deformation heterogeneity inherited from the deformed multi-phase structures. Reliable predictions regarding the recrystallization kinetics, grain size distribution and microstructure morphology can be made compared with the experimental results. The influence of annealing temperatures and heating rates is also obtained by the simulation approach. [ABSTRACT FROM AUTHOR]

The coexistence of equiaxed α, lamellar α and β phase in a duplex-structure α/β titanium alloy not only benefits the balance between strength and ductility, but also arouses a complicated microstructure evolution during hot deformation. The research objective herein is first to investigate the dynamic restoration mechanism, including dynamic recovery (DRC) and dynamic recrystallization (DRX), of both α and β phases during hot deformation of a duplex-structure TC21 titanium alloy. The results show that, after deformation, the geometric morphologies of lamellar α and β phase change more apparently than equiaxed α. Based on the analysis on the distribution and frequency of misorientation angle, it reveals that DRC and continuous DRX (CDRX) occur in all of equiaxed α, lamellar α and β phase, and the increasing deformation temperature restrains the occurrence of CDRX. Synthetically, the correlation between geometric morphology and dynamic restoration is well established. Meanwhile, the heterogeneous degree of DRX indicates a morphology dependent deformation heterogeneity between equiaxed and lamellar α, and between different local regions in β phase which is closely related to the distribution of equiaxed and lamellar α. The further discussion reveals that the morphology dependent deformation heterogeneity is fundamentally attributed to the different orientation relationship (OR) between β phase and equiaxed/lamellar α. This new find enriches the understanding on the deformation heterogeneity of titanium alloy, which was mainly attributed to the difference in crystallographic orientations in past decades. [ABSTRACT FROM AUTHOR]

A phenomenological crystal plasticity finite element (CPFE) model based on Voronoi grains was applied to reproduce basic deformation features of a hot-extruded magnesium alloy sheet under various strain paths. Corresponding experimental investigations, including mechanical tests, electron back scattered diffraction (EBSD) measurements and optical observation, were also carried out as either a validation or a supplement of the numerical results. Predicted average stress-strain responses and texture evolution are in good accordance with measured ones. Furthermore, deformation heterogeneity at the mesoscopic and intergranular scale were investigated based on the proposed model. At the mesoscale, the heterogeneity in the slip-dominated cases tends to develop continuously, whereas the heterogeneity is retarded in twin-favored deformation. At the intergranular scale, it is concluded from the slip-dominated case that a high slip-transfer parameter and high Schmid factors (SFs) of principal slip systems in adjacent grains could accommodate higher local strain. [ABSTRACT FROM AUTHOR]

The cold-rolled TRIP-assisted lean duplex stainless steel (TLDX) showed the directional distribution of constituent-fiber structure. The effect of phase distribution of constituent-fiber structure on the deformation heterogeneity during tensile tests and deep drawing of cylindrical cup was investigated through crystal plasticity finite element model (CPFEM) involved in the martensitic transformation. The results showed that the strain for the plastic instability was lower in the transverse direction (TD)-loaded case (true strain ε T ∼0.408) compared with the rolling direction (RD)-loaded case (ε T ∼0.485). Also, the strain localization bands formed at a lower strain (engineering strain ε E ∼40%) in the TD-loaded case than that in the RD-loaded case (ε E ∼55%). At the same strain, the volume fraction of transformed martensite of the TD-loaded case was relatively less than that of the RD-loaded case. For the transformed martensite, it only accommodated a low proportion (<5%) of global strain in the two cases. The proportion of partitioned strain into austenite (P ε γ ) in the RD-loaded case was always higher than that in the TD-loaded case, while the partitioned strain into ferrite (P ε α ) showed a converse law, which indicated that the deformation heterogeneity in the TD-loaded case is more pronounced. Similarly, the high risk of cracking of deep-drawn cylindrical cups with different sizes also always formed at the specific zones corresponding to the TD-loaded case. • The martensitic nucleation model based on CPFEM is effectively realized. • The proportion of partitioned strain is analyzed to quantify the role of elongated phase fibers. • The sum and distribution of martensite caused by elongated phase fibers are analyzed. • The crack failure behaviors of cylindrical cups are revealed by partitioned strain. [ABSTRACT FROM AUTHOR]

[Display omitted] • Slip transmission at grain boundaries is characterised by SEM and EBSD at early stage of deformation. • A strain gradient crystal plasticity finite element model is developed. • Criterion for slip transmission is determined from experiment and compared against CPFEM simulations. • Effect of slip transmission on flow strength and deformation localisation are evaluated using CPFEM model. This study explores the phenomenon of slip transmission across grain boundaries in coarse-grained copper. The associated effects on the deformation gradient are also investigated, using both experiment and simulation. An in-situ tensile test of a fully annealed copper specimen was conducted first using a scanning electron microscope (SEM). The deformation gradient and geometrically necessary dislocation (GND) maps at selected tensile strain values were obtained and characterized by electron backscatter diffraction (EBSD). In addition, a physically based strain gradient crystal plasticity finite element method model has been developed to simulate the early stage of tensile deformation behaviour of copper. In this model, slip transmission across the grain boundary is either allowed or blocked, depending on the alignment of adjacent grains. Slip transmission is allowed at grain boundaries between suitably aligned grains according to the Luster-Morris factor, residual Burgers vector is applied to consider the slip misalignment at GB region, and dislocation accumulation at grain boundaries is included following the Kocks-Mecking law. It was found that dislocation pile-up, lattice rotation and stress concentration were much higher near the impenetrable grain boundaries than at the penetrable ones. Due to the slip transmissions across grain boundaries, the stress and strain concentrations can be partially relaxed, and the slip transmission induced relaxation is associated with the number of active slip systems and shear strain on the best aligned slip systems. This study provides an effective strategy to investigate the early stage of plastic deformation, and a good agreement between experimental observations and simulation results has been achieved. [ABSTRACT FROM AUTHOR]

This paper focuses on the development of an appropriate Digital Image Correlation (DIC) methodology based on Image Registration and dedicated for characterizing the plastic deformation in single crystals. A pure nickel single crystal specimen is plastically deformed in tension and investigated by DIC technique. Based on the measured kinematic fields, the proposed method enables to identify the slip activity on the crystal surface and to locate precisely the slip band interfaces at microscale which behave as kinematic discontinuities. The computed displacement data are projected on a well-defined physical basis containing slip details, then the strain fields can be derived directly from a set of analytical functions. The possible errors in displacement induced by this projection approach are evaluated. Finally, some results of the evaluated strain fields are presented. It demonstrates that the developed DIC methodology allows quantitative characterization of a heterogeneous deformation process and promotes further relationships to be established between slip activity and strain field evolution in single crystals. [ABSTRACT FROM AUTHOR]

Understanding the mechanism of high temperature deformation is important for controlling the forming quality of the titanium alloy forgings. In the present work, the flow softening mechanism in subtransus deformation of titanium alloys with equiaxed structure was investigated by interrupted isothermal compression tests. The results show that limited strain hardening followed by continuous flow softening occurs in high temperature deformation of a two-phase TA15 titanium alloy. The flow softening can not be rationalized by dynamic recrystallization. Instead, the increase of mobile dislocations during deformation is an important reason for flow softening. The grain boundaries (including the α-β interfaces) act as an important source for the generation of mobile dislocations. The continuous flow softening results from the significant deformation heterogeneity in subtransus working. [ABSTRACT FROM AUTHOR]

Abstract: Cyclic deformation response of Ti-5553 alloy with β–α bimodal structure is systematically studied through total strain controlled fatigue tests. Results on the relationship between mechanical response and microstructure evolution are presented in this report. It was found that cyclic hardening/softening behavior of the alloy depended strongly on the applied strain amplitude. At low strain levels, the material showed moderate hardening behavior at the early stage of cycling and then behaved elastically; whereas at high strain amplitudes, the alloy showed softening behavior from the beginning to the end of cycling. In the intermediate strain range, moderate hardening at the beginning followed by softening was detected. Transmission electron microscopy investigation revealed that such special macroscopic responses were due to the microstructure heterogeneity in the material. The activation and participation in the cyclic deformation of different constituents, namely the soft primary αp phase, the higher strength transformed β phase and the fine embedded αs precipitates in the β matrix played different roles at different strain levels and at different stages of cycling. Thus, the aforementioned specific cyclic hardening/softening behavior was introduced. Specifically, dislocation activities including activation of multiple slip systems and annihilation of pre-existing dislocations in the primary αp phase were found to play a very important role in the overall cyclic deformation behavior. [Copyright &y& Elsevier]

Abstract: The mechanical properties and microstructure of commercial purity copper subjected to various pressure values in a compression stage of high-pressure torsion (HPT) were investigated here by analyzing microhardness, deformed geometry, and electron back scattering diffraction images along the radial direction of the compressed disks. Compression before torsion significantly increases the hardness and low angle grain boundary in the center as well as in the intermediate and edge regions. It is found that the compressive strain is the reason for the increased strength and refined grain size in the center region during HPT. This result sheds light on the strategy for achieving microstructure and property homogeneity in HPT. [Copyright &y& Elsevier]

The aim of the present study is to explain the role of chemical composition and heterogeneity within the microstructure of nodular cast iron on the micromechanisms of fracture. The heterogeneity in chemical composition is revealed by a thorough study of the microstructure using scanning electron microscopy, Auger electron spectroscopy and colour etching. The ferritic phase surrounding the graphite globules is enriched by silicon and depleted of manganese in the range of micrometres. Maximum manganese concentration is found in regions distant from these particles and in pearlitic regions. Simultaneously, ferritic grain boundaries in the vicinity of the graphite particles are enriched in phosphorus in the nanometer range. This interfacial segregation, reaching nearly 15 at.-%P, is most probably responsible for an embrittlement of these regions and the appearance of intercrystalline decohesion. An elastic-plastic finite element analysis of the ferritic/pearlitic microstructure demonstrates that a heterogeneous microstructure is locally subjected to heterogeneous stresses and strains, which are also expected to affect fracture mechanisms. [ABSTRACT FROM AUTHOR]

“Lazy ACF Tiles”, a macro written for the public domain program “NIH Image”, is presented. The macro permits the user to calculate local and bulk autocorrelation functions (ACFs) of halftone images such as photomicrographs of geological thin sections. Single ACFs, rows, or tessellations of ACFs can be calculated. ACF analysis is especially useful for the detection of subtle microstructures (weak anisotropies), and for the evaluation of large data sets. Segmentation of images (grain boundary contouring) is not necessary. Images do not have to be square. The macro is in the public domain, and a powerpoint manual is provided with it. As an example, the application of “Lazy ACF Tiles” to an experimentally deformed sample of quartzite is demonstrated. The ACF analysis reveals a periodic flattening intensity along the compressional axis of the sample, which cannot be detected with the unaided eye. [Copyright &y& Elsevier]

[Display omitted] • MCG grain size plays a significant role in strain partitioning. • MCGs can be refined by limited cold deformation followed by rapidly heating process. • Distinct dislocation piles up in MCG GBs under small deformation and initiates SRX. • SRX occurs at both GBs and interior of the MCG when deformation is relatively large. The defect of mixed-grain structure with millimeter-grade coarse grains (MCGs) is frequently found in heavy forgings, such as nuclear main pipes manufactured from 316LN steel. Renovation of such kind forgings can only be conducted through recrystallization. However, the allowed deformation is limited because the geometric size of forgings should be maintained during the renovation. For this purpose, the deformation heterogeneity of 316LN steel with mixed-grain structures were studied experimentally, which demonstrated that the MCGs were more inclined to deform than fine grains even if MCGs are with hard orientations. Therefore, a two-stage method was studied to refine MCGs, which takes the advantage of this deformation heterogeneity. The first stage was to impose a limited deformation to the steel at room temperature, suppressing the dynamic recovery and leading the preferentially deformed MCGs to accumulate enough deformation energy storage. The second stage was rapidly heating the deformed materials to realize static recrystallization (SRX). The results showed that the MCGs were completely refined by SRX even if the reduction rate is only 8%. The SRX mechanisms and refining assessments of MCGs under different deformation conditions were discussed. This work, thus, provides an effective method to salvage the heavy structures in engineering. [ABSTRACT FROM AUTHOR]

Deformation of single phase and two phase materials can be heterogeneous depending on the grain size distribution, orientation of the grains, amount and arrangement of the second phase and phase transformation during plastic deformation and twins. The deformation heterogeneity requires generation of geometrically necessary dislocations (GND) to maintain contact of the deforming grains and phases. Depending on the amount and character of deformation at the microscopic length scale, the evolution of the GND density changes. The present paper discusses the buildup of the GND density in different microstructural configurations using, single phase ferritic interstitial free (IF) steel, dual phase (DP) steel containing ferrite and martensite and austenitic stainless steel prone to deformation induced martensitic transformation and twining and whether GND density can be used as a descriptor of the deformation characteristics of the materials. The estimation of GND content using electron backscatter diffraction (EBSD) is recognized. The application potential of the present study is in understanding the in-grain deformation behavior of single phase IF steel, two phase DP steel, transformation induced plasticity assisted austenitic stainless steel to assess the forming of the steels for automobile applications. It should also facilitate the validation of strain gradient plasticity dependent damage model. • Microscale deformation mechanism is probed in IF, DP and austenitic stainless steels. • Evolution of geometrically necessary dislocation density is quantified with strains. • Microstructural heterogeneities effect geometrically necessary dislocation evolution. • Impact of geometrically necessary dislocation density on work hardening is assessed. [ABSTRACT FROM AUTHOR]