On the development of the goss texture in iron-3% silicon

A simple laboratory technique was developed to produce Goss-oriented specimens starting with commercial hot band of Fe-3.3%Si. The evolution of microstructure and texture including its throughthickness variation was followed through the subsequent stages of processing until final secondary recrystallization; the underlying mechanisms are discussed. In addition to pole figure determination the more quantitative and sensitive Orientation Distribution Function (ODF) analysis was applied. The results indicate that the structure of the hot band itself, consisting of large recrystallized grains of Goss orientation in the surface layers, exerts a strong influence on the eventual development of a sharp {011}〈100〉 Goss texture. Shear bands were observed after the first stage of cold rolling, and after the subsequent intermediate anneal, second cold rolling and primary recrystallization, strong 〈111〉∥ND fibres were observed. Through ODF analysis, a small number of {011}〈 100〉 oriented grains were revealed in the texture after primary recrystallization, again predominantly near the surface so that by chemical etching many of them could be removed. During the subsequent secondary recrystallization, these “Goss-nuclei” grew at the expense of all other matrix grains.     

Texture distribution through-the-thickness after cold-rolling of 3% silicon steel

A simple laboratory technique was used to produce cold-rolled specimens with various reductions from 40 to 80% at a 10% interval starting with commercial hot band of 3% silicon steel. The quantitative and sensitive Orientation Distribution Function (ODF) method was applied to analyze the evolution of texture from hot-rolled to cold-rolled through-thickness. The results indicated that there are two different types of texture in hot sheet which are called recrystallization type texture and deformation type texture. The developed texture at each level of cold sheet specimens was inherited from the texture at respective level of hot sheet. The Goss texture memory effect at subsurface level was discussed. The conclusions indicated that it is important to get suitable hot band which has strong recrystallization type texture at its surface level and use appropriate cold rolling reduction for producing cold band which has a texture distribution of strong {111}〈112〉, weak {001}〈110ång; and some {110}〈001〉 components at its subsurface level and is beneficial to forming sharp Goss texture during recrystallization. The appropriate reduction is about 70%.     

Analysis of primary recrystallization texture and grain boundary character distributions of low temperature grain- oriented silicon steel

In surface, sub- surface and center layer of low temperature grain- oriented silicon steel, the primary recrystallization texture and GBCD(Grain Boundary Character Distributions) based on HE (High Energy) and CSL (Coincidence Site Lattice) grain boundary theories were studied by EBSD(Electron Backscattered Diffraction). The results show that the primary recrystallization textures are mainly ?? fiber and {114}??418?? texture. Goss grains are mainly distributed on the surface and subsurface layer and the average grain size decreases gradually from the surface to the central layer. The misorientation distribution between the matrix and the Goss grains is mainly concentrated in the 20??-45?? which can form the high energy grain boundary, and the Goss grains in the sub- surface layer has the highest proportion of misorientation in 20??-45??. The type of CSL grain boundary is mainly ??3 and a little ??5, ??7, ??9 boundaries could be found in matrix.     

低温加热取向硅钢组织与织构演变研究

采用OM、EBSD、XRD分析研究了含Cu低温加热取向硅钢组织、织构的演变特征,研究结果表明：热轧板中存在铁素体层和珠光体层彼此交替的带状组织,且显微组织在厚度方向上分布不均匀,热轧板中{001}〈110〉、{112}〈110〉织构以及{110}〈001〉织构在板厚方向上分布不均匀;经过冷轧后,铁素体晶粒被严重拉长,形成了沿轧向伸长的纤维状组织,冷轧板织构类型主要是α织构和γ织构;脱碳时基体发生回复再结晶,显微组织为单一的铁素体等轴晶粒,织构主要为γ织构;二次冷轧板经渗氮后织构仅从强度上有所降低,其织构类型变化不明显。成品二次再结晶组织发展比较完善,晶粒尺寸约为10~20 mm。织构类型为锋锐的Goss织构。成品磁感B800达到了1.926 T,铁损P1.7/50为1.047 W/kg。     

Formation of Cube and Goss Texture After Primary Recrystallization in Electrical Steels

Recrystallization texture evolution in 2.1 pct Si electrical steel sheets was investigated with X-ray diffraction and electron backscattered diffraction (EBSD) analysis. The beneficial Cube ({100} 〈001〉 ) and Goss ({110} 〈001〉 ) components dominate primary recrystallization texture after final annealing at 1123 K (850 °C). It is found that Cube grains nucleate within {114} 〈481〉  deformed grains, and the nucleation of Cube grains is later than that of Goss grains during recrystallization. The formation of strong Cube and Goss texture is explained in terms of both the oriented nucleation and selective growth mechanisms.     

冷轧压下率对无抑制剂取向硅钢初次再结晶退火的影响

对无抑制剂取向硅钢不同压下率下初次再结晶退火后的显微组织、宏观织构和微观织构进行了研究.结果表明,冷轧板织构主要为α取向线{001}＜110＞、{112}＜110＞和{111}＜110＞织构以及γ取向线{111}＜110＞织构.初次再结晶退火后,α取向线织构减弱,织构主要为γ取向线{111}＜112＞织构.随冷轧压下率的增加,冷轧和初次再结晶织构强度增加.当压下率为88％时,初次再结晶退火后 Goss 织构和{111}＜112＞织构强度最高,最有利于发生二次再结晶.EBSD 分析显示,Goss 取向晶粒大多与{111}＜112＞取向晶粒相邻.提高冷轧压下率,Goss取向晶粒和{111}＜112＞取向晶粒都增加,Goss 取向晶粒偏离理想取向角度减少.     

0.20 mm薄规格取向硅钢的开发及关键工艺探讨

为开发磁性能优良的0.20 mm薄规格取向硅钢,对该取向硅钢的组织特征,不同冷轧压下率和高温退火气氛对磁性能的影响进行了研究。结果表明：所获得的0.20 mm薄规格取向硅钢成品组织二次再结晶完全,铁损（P1.7/50）为0.89 W/kg,磁感（J800）为1.906 T;热轧和常化1/8层的主要织构组分为Goss织构,冷轧织构为较强的{001}〈110〉,退火织构主要为{411}〈148〉,脱碳晶粒尺寸约为21.17 μm,Goss晶粒极少;0.20 mm薄规格取向硅钢合适的冷轧压下率为91.3 %;高温退火升温段合适的气氛为75% N2。     

二次冷轧压下率对镀锡板组织和性能的影响

 为了开发二次冷轧镀锡板,采用硬度计、拉伸试验机、光学显微镜、透射电镜和X射线衍射仪研究了二次冷轧压下率对镀锡板组织和性能的影响规律。结果表明,随着二次冷轧压下率提高,试验钢的硬度和强度提高,各向异性增加,伸长率降低,当二次冷轧压下率为20%时可获得较高的硬度和伸长率的匹配。同时二次冷轧压下率对织构影响明显,当压下率为20%～40%时,α取向线中最高取向密度出现在{223}〈110〉～{445}〈110〉之间,可达到6.2,并且随变形量增加,γ取向线中{111}〈110〉取向密度逐渐从3.1降低到2.7,{111}〈112〉取向密度逐渐从4.9提高到5.3。     

Static Recrystallization Kinetics and Crystallographic Texture of Nb-Stabilized Ferritic Stainless Steel Based on Orientation Imaging Microscopy

In the present study, Nb-stabilized ferritic stainless steel was prepared with annealing (430-A) and without annealing (430-NA) annealing, and the microstructure of the resulting samples was examined. The steel was then subjected to cold rolling and isothermal annealing in order to analyze its recrystallization kinetics and texture evolution. Microstructural characterization was performed by scanning and transmission electron microscopies. Recrystallization kinetics were evaluated by measuring the microhardness of the samples, and analyzing their kernel average misorientation and grain orientation spread via electron backscatter diffraction. The Avrami exponent data revealed that one-dimensional grain growth occurred owing to the migration of high-angle grain boundaries. The mean activation energies for recrystallization for 430-NA and 430-A was found to be 365 and 419 kJ mol⁻¹, respectively. The recrystallization texture was influenced by oriented nucleation and selected growth mechanisms, as well as by the Nb carbonitride distribution and grain boundary energy. The recrystallized and growing grains with the {554}〈225〉 orientation showed a dimensional advantage over the other recrystallized components. The coincident site lattice boundaries were attributed to the progression of recrystallization since the CSL numeric fraction increased as the temperature increased. The {554}〈225〉 component was associated with the ∑19a boundary, which exerted a significant control on the selective growth during the recrystallization.

     

Development of recrystallization textures in 0.08%C steel

The present work investigates the effect of cold deformation on the evolution of microstructure and textures during recrystallization in 0.08%C steel. The cold rolling texture consists of partial α-fiber (RD//〈110〉) and complete γ-fiber (ND//〈111〉) along with Goss ({110}〈001〉) and cube ({100}〈100〉}) texture components. The sharpness of α-fiber, γ-fiber and cube component increases with the increase in rolling reduction from 70 to 85% while that of Goss component decreases. After recrystallization (750 and 800°C), the textures were composed of α and γ-fiber along with significant Goss components. The strength of γ-fiber decreases after annealing. The presence of Goss component in recrystallization textures is attributed to preferential nucleation in {111}〈112〉 type deformed grains.     

Twinning-induced sluggish evolution of texture during recrystallization in AISI 316L stainless steel after cold rolling

This paper deals with the evolution of texture in AISI 316L austenitic stainless steel during annealing after 95 pct cold rolling. After 95 pct cold rolling, the texture is mainly of the brass type {110}〈112〉, along with a scatter toward the S orientation {123}〈634〉 and Goss orientation {011}〈100〉. Weak evidence of Cu component is observed at this high deformation level. During annealing, recovery is observed before any detectable recrystallization. Recrystallization proceeds through nucleation of subgrain by twinning within the deformed matrix and, later, preferential growth of those to consume the deformed matrix. After recrystallization, the overall texture intensity was weak; however, there are some discernible texture components. There was no existence of the brass component at this stage. Major components are centered on Goss orientation and Cu component {112}〈111〉 as well as the BR component {236}〈385〉. Also, a few orientations come up after recrystallization (i.e., {142}〈2−11〉 and {012}〈221〉). With increase in annealing temperature, the textural evolution shows emergence of weak texture with another new component, {197}〈211〉. The evolution of texture was correlated with the deformation texture through twin chain reaction.     

MgO涂层对Hi-B钢织构与抑制剂的影响

研究了MgO涂层对Hi-B钢高温退火过程中组织织构与抑制剂的影响。借助磁性能测试仪测试其磁性能,使用金相显微镜(OM)观察试样组织,借助扫描电子显微镜(SEM)和EBSD技术进行抑制剂观察和织构检测,利用投射电子显微镜(TEM)及能谱仪(EDS)进行能谱分析。结果表明:氧化镁涂层能延缓抑制剂粒子的分解,保持较高的粒子分布密度,进而抑制初次再结晶晶粒的粗化,提高二次再结晶的开始温度。另一方面涂层能影响二次再结晶过程。无涂层样品与氢气直接接触,较多接近{110}面织构而与〈001〉晶向偏差较大的晶粒发生了异常长大,导致二次再结晶晶粒数量更多,尺寸更小且Goss织构比较散漫。有涂层样品Goss织构更加锋锐且磁性能更优。     

Fe-6.5%Si合金温轧后退火过程中再结晶行为

用电子背散射技术观察了700℃温轧板在退火过程中的组织及织构演变以了解其再结晶行为.结果表明,温轧织构由强的（111）〈112〉、较弱的〈110〉∥RD及Goss组成,再结晶织构与之相似.〈110〉∥RD及（111）〈112〉新晶粒首先形成于与之构成小角度晶界的形变晶粒的晶界附近,而在角隅及组织不均匀区等位置孕育出与周围晶粒构成大角度晶界的晶核,择优取向不明显.退火过程中（111）〈112〉在形变组织中累积,最终转化为（111）〈112〉再结晶晶粒.分析认为,温轧后退火是不均匀组织在低储存能驱动下的再结晶过程.（112）〈110〉及（111）〈112〉形变拉长晶粒多发生连续再结晶从而退火织构与形变态相似.在角隅区形成核心进而发生不连续再结晶,核心取向的统计性及不连续晶核的长大弱化再结晶织构,其中Goss晶粒多以此方式形成于（111）〈112〉晶粒内部.     

薄板坯连铸连轧流程Fe-3%Si钢热轧板和常化板织构

在实验室按照薄板坯连铸连轧工艺流程试制了Fe-3%Si硅钢热轧板,采用EBSD和X射线衍射方法观察了A钢和B钢热轧板和常化板的织构组织,分析了α、ε和γ取向线上织构取向密度变化规律。A和B钢热轧板具有相似的{110}〈112〉和、{001}〈110〉和{001}〈010〉和高斯织构组织,A试样表层的晶粒均匀性较差,B试样具有较强的γ织构取向。采用EBSD观察比较了A钢和B钢热轧板和常化板的垂直TD面的EBSD微观织构组织,A钢和B钢常化退火后基本保留了热轧时形成的中心部位的组织,而次表层和表层晶粒发生了再结晶长大,晶粒组织和织构梯度减小,织构主要集中在{001}〈^-1^-10〉和{001}〈0^10〉和之间以及高斯织构上。常化后织构的总体强度下降,高斯强度减弱。试验研究结果为开发薄板坯连铸连轧短流程生产电工钢技术提供理论依据和参考数据。     

The role of niobium as microalloying element in electrical sheet

The processing route of grain oriented electrical sheet was simulated by laboratory trials. Besides MnS, the effect of AIN and NbC as an inhibitor phase in 3 % silicon steel was also investigated. In the hot strip material the niobium microalloyed steel showed the highest volume fraction of the {110}<001> Goss texture at 0.3 to 0.4 mm below the surface. This superiority was maintained after cold rolling and annealing after both, one step or two step cold reduction schedules. A volume fraction of the Goss texture of more than 80 % is typical for this steel concept. It can be explained by the solubility product of NbC, which guarantees grain size control during the primary recrystallisation processes and allows the Goss texture component to grow during secondary recrystallisation, which usually follows a steel decarburisation. Consistent with the highest volume fraction of Goss texture, the core losses are lowest in the sheet using NbC as an inhibitor phase.     

初次再结晶退火对模拟CSP含Cu Hi-B硅钢组织和织构的影响

在实验室用模拟CSP工艺试制Hi-B高磁感取向硅钢薄板（/%:0.07C,3.02Si,0.13Mn,0.020P,0.006S,0.21Cu,0.025Cr,0.016A1,0.004Sn）,该钢经25kg真空感应炉熔炼,铸成41 mm×120 mm板坯-热轧成2mm板-1 120℃常化-冷轧成0.27mm薄板。研究了830~870℃,3~7min退火对再结晶组织和织构的影响。结果表明,0.27mm含Cu Hi-B高磁感取向硅钢板的合适退火工艺为830℃ 5 min,其平均晶粒尺寸为15.6μm,不利织构{111}〈110〉和{001}〈110〉含量较低,有利织构{111}〈112〉分布合理,有利于在二次再结晶退火过程形成良好的高斯组织。     

普通取向硅钢轧制过程中组织和织构的演变

借助电子背散射衍射(EBSD)及ZEISS-200MAT金相显微镜对某钢厂普通取向硅钢(CGO)进行研究,研究结果表明:热轧板组织、织构沿板厚方向存在明显的不均匀性,在热轧板表层及次表层发生再结晶,同时存在强度较高的Goss织构,中心层存在较强的{001}110变形织构。冷轧组织均呈纤维状条带组织,一次冷轧后,热轧板中的Goss织构消失,织构主要为α、γ织构,经中间脱碳退火后,α、γ织构强度减弱,并出现一定强度的Goss织构和利于Goss织构发展的{554}225、{332}113等织构,经二次冷轧后,二次冷轧织构类型与一次冷轧织构一致,但织构强度不同。     

Coincidence grain boundary and role of inhibitor for secondary recrystallization in Fe-3% Si alloy

Secondary recrystallization behavior in the presence of AlN and MnS precipitates in Fe-3% Si alloy, processed by one stage cold rolling method, was investigated with special reference to a role of inhibitor for secondary recrystallization. The sharpness of Goss secondary texture is higher in the early stage of secondary recrystallization. In the case of stronger grain growth inhibition by precipitates during secondary recrystallization, the evolution of secondary recrystallized grains in orientations dispersed from Goss orientation is smaller than that in the case of weaker grain growth inhibition. The mechanism of these experimental results is explained by the specific grain boundary migration characteristics in the presence of inhibitor, namely, the critical frequency of Σ9 coincidence oriented grains in relation to nucleus for the evolution of secondary recrystallization is considered to be higher in the case of stronger grain growth inhibition during secondary recrystallization.     

Secondary recrystallization of pure molybdenum wires

The secondary recrystallization of drawn pure Mo wires has been studied; a particular attention has been paid on the effect of temperature gradients in the annealing process. The secondary recrystallized grains being very elongated along the wire axis have been obtained by annealing in a moderate temperature gradient furnace at about 2000°C. Orientations of the wire axis of the secondary recrystallized grains are mainly 〈023〉 or 〈135〉, while 〈011〉 oriented grains are less frequently observed. In contrast, the primary recrystallized texture consists of the 〈011〉 main component and 〈023〉-〈012〉 sub-component; many 〈011〉 oriented grains have large grain sizes. The observed discrepancy in orientation between the primary and secondary recrystallized grains is explained in terms of the difference in grain boundary mobilities which depend on the character of grain boundaries.     

Sn和冷轧板厚度对取向硅钢初次再结晶组织和织构影响

研究了Sn含量和冷轧板厚度对取向硅钢冷轧板脱碳渗氮退火后组织和织构的影响,发现随着厚度减小和Sn含量增加,初次再结晶晶粒尺寸趋于减小,增加Sn含量导致对Goss取向形成的不利织构{001}〈120〉增加,而钢板厚度减薄时{111}〈112〉、{411}〈148〉等有利织构和{001}〈120〉不利织构均增加。Sn在氧化层中的含量显著小于基体,在氧化层/基体的界面处有显著的浓度梯度。虽普遍认为Sn的晶界偏聚是影响退火组织和织构的原因,但俄歇电子能谱只能偶然检测到,推测或是该偏聚不具有普遍性,或是其偏聚厚度极小超出了仪器检测的范围。