Cold Rolling Texture Research Articles

Evolution of Through-Thickness Texture in Ultra Purified 17% Cr Ferritic Stainless Steels

Texture inhomogeneity usually takes place in ferritic stainless steels due to the lack of phase transformation and recrystallization during hot strip rolling, which can deteriorate the formability of final sheets. In order to work out the way of weakening texture inhomogeneity, conventional hot rolling and warm rolling processes have been carried out with an ultra purified ferritic stainless steel. The results showed that the evolution of through-thickness texture is closely dependent on rolling process, especially for the texture in the center layer. For both conventional and warm rolling processes, shear texture components were formed in the surface layers after hot rolling and annealing; sharp a-fiber and weak γ-fiber with the major component at {111}<110> were developed in both cold rolled sheet surfaces, leading to the formation of inhomogeneous γ-fiber dominated by {111}<112> after recrystallization annealing. In the center layer of conventional rolled and annealed bands, strong a-fiber and weak γ-fiber textures were formed; the cold rolled textures were comprised of sharp a-fiber and weak γ-fiber with the major component at {111}<110>, and inhomogeneous γ-fiber dominated by {111}<112> was formed after recrystallization annealing. By contrast, in the centre layer of warm rolled bands, the texture was comprised of weak a-fiber and sharp γ-fiber, and γ-fiber became the only component after annealing. The cold rolled texture displayed a sharp γ-fiber with the major component at {111}<112> and the intensity of γ-fiber close to that of a-fiber, resulting in the formation of a nearly homogeneous γ-fiber recrystallization texture in the center layer of the final sheet.

Microstructure and Properties of Ultrafast Annealed High Strength Steel

The grain size, recrystallization, phase transformation and mechanical properties of a cold-rolled high-strength steel (HSS) are studied after annealing with high (~140°C/s) and ultra-high (~1500°C/s) reheating rate, followed by subsequent water quenching without isothermal soaking. By monitoring the hardness and microstructure, it was shown that the increase of the reheating rate from 140°C/s to 1500°C/s causes grain refinement from 5 µm to 1 µm in diameter and the final ferrite grain size depends significantly on the reheating temperature and reheating rate. It was observed that after an extreme reheating rate of ~1500°C/s the α-γ phase transformation starts before the completion of recrystallization in the recovered matrix. The crystallographic texture of the ultrafast reheated and water-quenched high-strength steel inherits the cold-rolled deformation texture with well pronounced RD and ND texture fibres, even after the α-γ-α′ phase transformations. It was found that the ultrafast reheating results in a very fine non-equilibrium ferrite-martensite structure with an excellent ultimate tensile strength of ~1400 MPa and an acceptable elongation at fracture. The observed data are very promising from industrial application point of view and open up possibilities for further structural refinement and alternative texture control.

Texture evolution of commercial pure Ti during cold rolling and recrystallization annealing

X-ray diffraction (XRD) was employed to analyze the texture evolution of commercial pure (CP) Ti during cold rolling and recrystallization annealing. The texture components were measured by electron backscattered diffraction (EBSD) after recrystallization annealing. The CP Ti tends to form a texture with the basal pole tilted 30°–40° away from the normal direction toward the transverse direction. The texture of the initial hot-rolled plate can be classified into three kinds, i.e., the pyramid texture \(\left( {\bar 1013} \right)\left[ {5\bar 2\bar 30} \right]\) and \(\left( {\bar 2021} \right)\left[ {10\bar 15} \right]\), the basal plane texture \(\left( {0001} \right)\left[ {2\bar 1\bar 10} \right]\), and the stronger prism texture \(\left( {11\bar 20} \right)\left[ {0001} \right]\). After cold rolling and annealing (700°C, 60 min), the main texture components are the cold-rolled texture \(\left( {11\bar 25} \right)\left[ {11\bar 23} \right]\) and the recrystallized texture \(\left( {\bar 1013} \right)\left[ {5\bar 2\bar 30} \right]\). The texture \(\left( {\bar 2021} \right)\left[ {10\bar 15} \right]\) is inherited from the texture of the initial hot-rolled plate with the decrease of orientation density gradually. The volume contents of the cold-rolled texture \(\left\{ {\bar 2115} \right\}\left\langle {01\bar 10} \right\rangle\) and the recrystallized texture \(\left\{ {10\bar 13} \right\}\left\langle {1\bar 210} \right\rangle\) are calculated by EBSD. After recrystallization annealing, the specimen is rich in the recrystallized texture and inherits some of texture components from the cold-rolled texture. When the annealing time is prolonged, the anisotropic value decreases.

Recrystallisation Behaviour of an Fe-Mn-C-Si-Al TWIP

The static recrystallisation behaviour of cold rolled and annealed TWinning Induced Plasticity (TWIP) steels is important for its industrial production. The recrystallisation kinetics have been determined for an Fe-Mn-C-Si-Al TWIP steel using hardness measurements and microstructure analysis: it has been shown that recrystallisation progresses rapidly with increased annealing temperature. Recrystallisation was faster at higher cold reductions, and a smaller final grain size was observed at lower annealing temperatures. This indicates that the mechanism is nucleation dominated at lower temperatures; grain growth at higher temperatures appears similar for all reductions. The recrystallisation results in a crystallographic texture where the main components of the cold rolling texture are preserved in the final texture after annealing, although some randomisation was observed.

Determination of hot and cold rolling textures of steels: combined Bayesian neural network model

The work reported in the present paper outlines the use of a combined artificial neural network model capable of fast online prediction of textures in low and extralow carbon steels. We approach the problem by a Bayesian framework neural network model that takes into account as input to the model the influence of 23 parameters describing the chemical composition and the thermomechanical processes, such as austenite and ferrite rolling, coiling, cold working and subsequent annealing, involved in the production route of low and extralow carbon steels. The output of the model is in the form of fibre texture data. The predictions of the network provide an excellent match to the experimentally measured data. The results presented in the present paper demonstrate that this model can help in optimising the normal anisotropy rm of steel products.

Effects of Two-Step Cold Rolling on Recrystallization Behaviors in ODS Ferritic Steel

The recrystallization behaviors of Fe–15Cr ODS ferritic steels underwent two different processing routes were compared; (a) 1st 70% cold rolling + intermediate annealing, (b) 1st 70% cold rolling + intermediate annealing at 1100°C to make a recrystallization structure +2nd 70% cold rolling + final annealing. Hardness and texture changes during rolling and isochronal annealing were investigated. Results show that the recrystallization temperature of 70% cold rolled specimen is 950°C and the recrystallization texture is {111} . On the contrary, in the case of specimen which was cold rolled for two times, the recrystallization temperature increases to 1100°C, and the recrystallization texture changes to {111} . These changes are ascribed to the different routes of crystalline rotation during 1st and 2nd cold rolling, which produce different cold rolling texture. Higher {100} content induced by 2nd cold rolling after intermediate recrystallization which has low stored energy increases the recrystallization temperature. And the difference in texture intensity along γ fibre after 1st and 2nd cold rolling results in different recrystallization texture.

Through-Thickness Shear Strain in Silicon Steel under Asymmetric Rolling

Through-thickness shear strain variation with speed/radius/friction ratio in cold rolled silicon steel under different asymmetric rolling modes was analyzed by finite element method (FEM). Cold rolling textures were also investigated quantitatively to correlate with the calculated shear strain. With increasing speed/radius/friction ratio, shear strain distribution under differential-speed and differential-radius rolling exhibits similar characteristic in contrast to differential-friction rolling. Unidirectional shear strain develops through sheet thickness when asymmetric speed and radius ratio exceeds 1.125, whereas it does not appear even at friction ratio of 1.5. Shear strain distribution dependent on asymmetric rolling modes can be well understood by forward and backward slip zones as well as roll pressure as a function of speed/radius/friction ratio.

Study on Sensitization Susceptibility and Texture of Cold Rolled AISI 304LN Stainless Steel

Attempt has been made to correlate the cold rolling (CR) texture with the degree of sensitization (DOS) in rolled 304LN after ageing at 500-600oC for various durations. The susceptibility of sensitization is observed to increase with %CR cold rolling from 5-25% and aged at 500-600oC. No one to one correlation between texture and DOS is observed. Brass component, overall, seems better for lower DOS while Goss component led to relatively higher DOS values. It is observed that the ratio of Brass to Copper may have a critical value for lower DOS.

Texture Formation in High Strength Low Alloy Steel Reheated with Ultrafast Heating Rates

Texture formation during annealing of a 95% cold rolled HSLA steel with 10°C/s and ~3000°C/s was studied with the purpose to investigate the interaction between the recrystallization and the austenite formation as well as the possibility of grain refinement. The recrystallization and austenite formation were monitored by means of optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). It was found that at extreme reheating rates of 1000°C/s and higher, the α-γ phase transformation starts before the completion of recrystallization and the deformation texture is partially retained in the samples after annealing. The crystallographic texture observed in the martensitic phase which is the product of intercritical austenite transformation in as-quenched samples, i.e. after the double α-γ-α’ transformation, is the same as the initial cold rolling texture, which is an indication for the texture memory effect. After ultra fast reheating with average reheating rates of 1000°C/s and higher a significant grain refinement was observed with an average ferrite grain size of ~1µm. The obtained final ferrite grain size depends significantly on both the reheating temperature and the reheating rate.

Texture evolution of 440 MPa grade Nb-bearing high strength IF steel during rolling and annealing process

The texture evolution from rolling process to annealing process of 440 MPa grade Nb-bearing high strength IF steel (IF-HSS) was studied. Moreover, the texture of different section in thickness direction of steel sheet after annealing was investigated. Macro-texture measurements using XRD shows that hot rolling texture in Nb-bearing IF-HSS includes a weak γ-fiber and α-fiber, of which main texture components are {001}〈110〉,{111}〈110〉 and {111}〈112〉. It is worthy of note that the γ-fiber skeleton line formed after hot rolling. During cold rolling, the absolute maximum shifts to {111}〈112〉 along the γ-fiber and the maximum along the α-fiber shifts to {112} 〈110〉. During recrystallization annealing process, the weaker α-fiber and stronger γ-fiber cold rolling texture transformed to a very strong γ-fiber annealing texture. After annealing the main components from surface to mid-section along thickness display the same character for both α-fiber and γ-fiber, while textures intensity at 1/4 section is higher than that of surface and mid-section.

Texture Evolution during the Cold Rolled Low Carbon Steel Sheet under CSP Technology

In this item, the low carbon steel hot sheets by compact strip production (CSP) technology were cold rolled and annealed in laboratory. texture evolution during the production process of CSP-cold rolled strip were investigated by means of the XRD. The results were as follows: After hot deformation of thin slab formed a strong γ- fibre orientation texture, the density of texture increase with the cold rolled reduction increased, especially for the negative texture {100}, in γ-fibre orientation cold rolling texture density has no significant change. Compared to the traditional process, hot rolled steel sheet has higher texture, cold-rolled steel sheet has the same texture, and after-annealing sheet has further higher texture in the CSP-cold rolling process. This study enables better understanding and control on the evolution of textures the cold-rolled steel sheet processed by CSP technique and provides theory support for exploiting the CSP the cold-rolling deep drawing steel sheet

Texture and Ductility of Ni&lt;sub&gt;3&lt;/sub&gt;Al Foils

This article presents the texture evolution and the ductility improvement of the cold-rolled foils of boron-free Ni3Al during the recrystallization and the subsequent grain growth. The cold-rolled foils had sharp {110} textures. After the recrystallization at 873K/0.5h, the texture was disintegrated with several texture components. Interestingly, most of them had a single rotation relationship. i.e. 40˚ around &lt;111&gt;. With the progress of the grain growth, however, the texture returned to the sharp, cold-rolled textures. This two-stage texture evolution, called as “Texture memory effect”, was explained assuming a high mobility of the grain boundary with the 40˚&lt;111&gt; rotation relationship. The texture returning was highly effective to improve the ductility of the foils.

Effect of Finishing Temperature on Texture Evolution and Magnetic Properties in Heavy Cold Rolled High Silicon Steel Thin Sheets

0.2mm-thick high silicon steel thin sheet under 94% cold rolling reductions has been successfully produced by conventional rolling method. Texture evolution during hot rolling, cold rolling and final annealing as well as magnetic properties has been investigated with emphasis on the effect of finishing temperature. It is found that a favorable strong {001}&lt;210&gt; recrystallization texture and evidently improved magnetic properties can be obtained at the finishing temperature of 900°C, which is in contrast with relatively strong detrimental {111}&lt;112&gt; and weak {001}&lt;210&gt; recrystallization texture at the finishing temperature of 700°C. Effects of finishing temperature can be explained in terms of the cold rolling texture due to different texture morphology in hot bands.

Microtexture analysis of cold-rolled and annealed twinning-induced plasticity steel

The microtexture evolution of cold-rolled and isochronally annealed Fe–24Mn–3Al–2Si–1Ni–0.06C twinning-induced plasticity steel is investigated by electron back-scattering diffraction. Novel deconstruction techniques are applied to cold-rolled and partially recrystallized maps. The formation of cold-rolling texture via composite slip/twin deformation pattern is corroborated by the relatively random spatial distribution of twinned and untwinned grains. Whereas the orientations of the newly nucleated grains are similar to the deformation texture, orientation-dependent, stored energy and second-order twinning contribute to the end-recrystallization texture.

Microstructure and texture evolution of strip casting 3 wt% Si non-oriented silicon steel with columnar structure

An Fe-3 wt%Si strip with columnar structure and pronounced {0 0 1}〈0 v w〉 texture was produced using a twin-roll strip caster. Then the as-cast strip was cold-rolled and annealed. The microstructure and texture evolution along the processing steps was investigated. It is found that inhomogeneous microstructure is produced in both cold-rolled and final annealed samples due to the large initial grains. The cold rolling texture is dominated by pronounced a-fiber texture and relatively strong γ-fiber texture. The final recrystallization texture is characterized by {0 0 1}〈0 1 0〉, {0 0 1}〈2 1 0〉, {1 1 0}〈0 0 1〉 texture and a slightly shifted {1 1 1}〈1 1 2〉 component. The microstructural inhomogeneity plays an important role in the texture evolution.

Modeling of large plastic deformation behavior and anisotropy evolution in cold rolled bcc steels using the viscoplastic ϕ-model-based grain-interaction

In this paper, a micromechanical approach is used to predict the mechanical response and anisotropy evolution in BCC metals. Particularly, cold rolling textures and the corresponding yield surfaces are simulated using the newly developed viscoplastic intermediate ϕ-model. This model takes into account the grain interactions but without the Eshelby theory. In this work, we compare our results to those predicted by the upper and lower bounds (Taylor and Static) as well as those of the viscoplastic self-consistent (VPSC) model. The results are compared in terms of predicted slip activity, texture evolution and yield loci. For the simulations, we considered two cases: the restricted slip, {1 1 0}〈1 1 1〉, and the pencil glide, {1 1 0}〈1 1 1〉 + {1 1 2}〈1 1 1〉 + {1 2 3}〈1 1 1〉. In addition, we present a qualitative comparison with experimental cold rolling textures taken from the literature for several BCC metals: electrical, ferritic, Interstitial-Free (IF) and low carbon steels. Our results show that the pencil glide assumption is adequate for low carbon and IF-steels and that the restricted slip assumption is well suited for ferritic and electrical steels.

Texture of Cold Rolled Strip of Fe-3Si Steel Produced by Thin Slab Casting and Rolling

Abstract The hot rolled strip of Fe-3Si steel was experimentally produced by thin slab casting and rolling (TSCR) process in the laboratory. The texture evolution rule was investigated during hot rolling and cold rolling. The texture distribution of cold rolled strips with four kinds of cold rolling reduction schedules was observed through X-ray diffraction method, and the orientation density variation of 1/16 layer, 1/8 layer, 1/4 layer, and 1/2 layer in thickness was analyzed. The cold rolled texture of steel A with four kinds of cold rolling reduction schedules was mainly composed of α and γ fibers. Cold rolling reduction ratio of 70% was more beneficial for obtaining more γ fibers. The γ fiber texture orientation density of {111} ▪ and {111} ▪ was the largest on the 1/8 layer and 1/4 layer and the least on the 1/16 layer and 1/2 layer for steel B. The texture orientation density of {001} — {223} ▪ in the α fibers for steel C was increased, but the texture orientation density of {332} — {110} ▪ was low.

Effects of cold rolling on crystallographic texture of oriented silicon steel produced by TSCR

The cold rolling textures of oriented silicon steel produced by thin slab casting and rolling (TSCR) were studied in the laboratory. Based on φ2 = 45° sections of the X‐ray orientation distribution functions (ODFs) analysis, the subsurface texture of hot‐rolled sheet consists of ϵ(TD//〈110〉) fibres. The texture of cold‐rolled sheet mainly consists of α. (〈110〉//RD) and γ (〈111〉//ND) fibres, and Goss texture ({110}〈001〉) disappears. The γ‐fibre texture is clear for total reductions between 58% and 85%. The highest {111}〈112〉 orientation density of 6·6 can be obtained in one‐stage cold rolling by a two‐roller mill with Φ160 mm roller. When cold rolled to 1·0 mm by a two‐roller mill with Φ160 mm roller, then to 0·35 mm by a four‐roller mill with Φ90 mm working roller, this value decreases to as low as 2·8.

Effect of Texture on r-value of Ferritic Stainless Steel Sheets

The effects of cold rolling texture on the formation of recrystallization texture and the relationship between recrystallization texture and r-value were investigated for sheets of titanium-stabilized extra-high purity Type 436L and Type 409L ferritic stainless steels. The recrystallization texture and average r-value were affected by the cold rolling texture. Annealed sheets with a sharp γ-fiber texture and very high average r-values were obtained from cold-rolled sheets with a strong γ-fiber texture (Type A). On the other hand, the {h,1,1} fiber texture developed from cold-rolled sheets with a strong α-fiber texture (Type C). In terms of the relationship between {111} intensity and the average r-value, chromium content had less effect than the cold rolling texture. The planar anisotropies of r-values and the average r-values of Type 436L and 409L sheets with Type A cold rolling textures agreed well with those calculated from the textures in the center layers by using the relaxed-constraints model and the CRSS ratio τc{211}/τc{110} of 1.1. On the other hand, for the sheets with Type C cold rolling textures and a marked texture gradient, it was necessary to consider the texture gradient in the thickness direction. The texture inhomogeneity by the orientations other than {111} texture affected the relationship between {111} intensity and average r-value.

The Effect of Nb-Ti on Cold Rolling Texture and Recrystallization Texture of B4003M

In this study, the effect of different compositions of the stabilized elements of Nb-Ti for cold rollling textures and the recrytalization textures of B4003M has been investigated. Cold rolling texture at 80% reduction displayed by the Nb-Ti added specimen is the weakest of all. When annealing at 900°C for 10 min, the recrystalli -zation textures displayed by the Nb-added, Ti-added, Nb-Ti-added and Nb-Ti-free alloys are compared. Results show that: {111} recrystallization texture in Nb-added alloy is the strongest, whereas it in the Nb-Ti-free alloy is the lowest. The mutual effect of Nd and Ti on refining the grain size is more obvious than the single element effect, while Nd is more effective than Ti.