润滑对3104铝合金板变形织构的影响

在无润滑(WOL)和润滑(WL)2种轧制条件下,分别对2.3 mm厚的热轧3104铝合金板进行不同压下量的冷轧.应用取向分布函数(ODF)定量计算和分析在不同轧制压下量下润滑对3104铝合金板材沿板厚方向织构演变的影响.结果表明:随着轧制压下量的增加,样品各层的织构组分强度均逐渐增加;无润滑轧制时样品表面层主要织构组分取向密度普遍高于相同压下量下润滑轧制时的取向密度.导致表面层织构组分增强的原因是摩擦引起应变状态改变的结果.     

Stability of rolling texture during heat treatment in a two-phase Ti3Al base intermetallic alloy

The stability of hot rolling texture developed in the ₂ phase of a two-phase Ti₃Al base intermetallic alloy, during subsequent heat treatment, has been systematically investigated. The basal hot rolling texture remains rather stable during recrystallization annealing at temperatures within the single phase ₂ range. Grain growth after recrystallization produces extra orientations other than the basal. For the material with a starting basal texture, heat treatment in the upper ₂, (₂+β) or β phase fields does not change the basic character of the texture, although the sharpness and especially the width of the basal component increase to some extent with the increase in the heat treatment temperature. Heat treatment of material with starting non-basal texture in the upper ₂, (₂+β) or β phase fields does not produce any basal component irrespective of the heat treatment temperature. When the starting material is reasonably strain free and possesses a weak basal texture, heat treatment in the upper ₂, (₂+β) or β phase fields helps in intensifying the basal component to a certain extent.     

{411}<148> Texture in Thin-Gauge Grain-Oriented Silicon Steel

The significant occupancy of {411}<148> texture exists in the thin-gauge grain-oriented silicon steel (TG-CRGO is defined that thickness of the sheet is <0.25 mm and the reduction in cold rolling is more than 90%) which has been considered to have obviously effects on the abnormal growth of Goss-oriented grains during the secondary recrystallization process. The microstructures of the TG-CRGO were investigated by X-ray diffraction and electron back-scattered diffraction in this study. It was found that {411}<148> texture mainly exists in the center layer of hot-rolled as well as normalized plates. With the increase in cold rolling reduction, {411}<148> orientation gradually rotates to α-fiber texture (<110>//RD). Finally, few {411}<148> would retain at the boundaries of deformed α-fiber grains (<110>//RD) as the reduction in cold rolling reaches 90%. After annealing treatment, a small amount of γ-fiber textures (<111>//ND) preferably nucleates and recrystallizes between the DBs (deformation bands) at first; then, the {411}<148> recrystallization texture occurs and mainly nucleates at the grains boundaries of the deformed α-fiber grains, and also quite a few {411}<148> orientation grains nucleate in the inner of {112}<110> grains. But this phenomenon was not observed in the {100}<011> deformation grains. With respect to the occurrence of {411}<148> recrystallization texture, it is mainly induced by strong α-fiber as well as weak γ-fiber textures formed during cold rolling other than originating from {411}<148> regions in hot bands.     

新能源汽车用含稀土无取向硅钢生产过程中组织、织构演变

采用光学显微镜、X射线衍射仪及扫描电镜对含稀土无取向硅钢整个生产流程中的显微组织及织构演变进行研究。结果表明,热轧板在厚度方向上有显著的分层,即表层的再结晶层、过渡层、中间层的变形组织层,其织构主要包含铜型、黄铜型织构;正火后晶粒发生了完全再结晶,织构类型相对热轧基本无变化,但强度减弱;两次冷轧后的组织均为纤维组织,形成了以α、γ线性织构为主的织构类型,还出现了强度较高的反高斯织构如{001}<110>、{112}<110>、{111}<110>;脱碳退火后发生部分再结晶,织构相对于冷轧态α、γ线性织构强度均减小;在高温退火阶段晶粒发生再结晶,存在以{111}<112>、{111}<110>为主的γ织构,以及{100}<001>织构。     

Crystallographic Texture Evolution of ■-Fe_4N and Its Influences on Tribological Property of Nitrided Steel

The crystallographic texture of ■-Fe4 N in compound layer and its influences on the tribological properties of nitrided steel 38 Cr Mo Al are investigated in the study. The preferred orientation of(200)■ is produced by low-temperature nitriding in atmosphere with low nitrogen–hydrogen ratio and increases with the nitriding time. The preferred orientation of(220)■ appears after 72 h cyclic nitriding. The orientation relationships(0001)_ε//(101)_■ and [110]_ε//[111]_■,(111)_■//(0001)_ε and 011_■//[1■10]_g,(200)■//(110)_■ and [011]_■//[111]_■, as well as (1■03)_ε //(220)_■ and [0100]_ε//[1■0]_■ are established by first-principles method. The misfit of interatomic distance(δ), determining the phase transition resistance, is calculated. Accordingly, two reaction pathways during nitriding, ■→■ and ■→ε→■, are assumed, which determines the preferred orientations of ■-Fe_4 N. Results of wear tests demonstrate that the specimen with preferred orientation of(200)■ exhibits lower frictional coefficient and lower wear rate in comparison with the specimen with(220)■ preferred orientation.(111)■ texture usually relates to the lower frictional coefficient but higher wear rate due to the main slip system parallel to the sliding plane. Therefore, the(200)■ preferred orientation has a positive significance in improving the wear properties of steels.     

Microstructure,Mechanical Properties and Die-Filling Behavior of High-Performance Die-Cast Al-Mg-Si-Mn Alloy

This work aims to reveal the relationships between the microstructure,mechanical properties and flow behavior of die-casting AlMg_5Si_2Mn alloy.Results indicated that the microstructure of the die-cast AlMg_5Si_2Mn consists of α_1-Al grains,fine-size α_2~Al grains and(Al +Mg_2Si) eutectic.The surface layer observed has the thickness in a range of120-135 μm,while an ellipse-like surface layer edge is observed in the corner of the plate-like sample.Tensile strength and elongation(5) of the specimens are slightly decreased along the die-filling direction due to the backflow of melt.Pure(Al + Mg_2Si) eutectic layer and ultra-fine-size α_2-Al grains observed are around the overflow channels.Mass feeding is predominantly responsible for the superior mechanical properties of the round bars as compared to those of plate-like samples.     

超纯铁素体不锈钢织构演变与成形性能的研究

系统研究了超纯铁素体不锈钢(w(Cr)=17%)沿钢板厚度方向各层织构的演变规律和不同精轧温度对织构演变及成形性能的影响规律。采用X射线衍射仪分析了宏观织构演变。研究表明: 热轧及退火后, 钢板表层以剪切织构为主, 中心层由?和?纤维织构组成; 冷轧后, 各层均由较强的?纤维织构和较弱的?纤维织构组成; 冷轧退火后各层均形成?纤维再结晶织构。与高温精轧相比, 低温精轧有利于冷轧退火板?纤维再结晶织构的强化、偏离{111}<112>组分的程度降低, 从而显著改善冷轧退火板的成形性能。     

含铜低温取向硅钢轧制过程中的组织及织构演变

采用Zeiss光学显微镜及X射线衍射仪对含铜低温取向硅钢生产过程中热轧、一次冷轧、脱碳退火和二次冷轧阶段的显微组织与织构的演变规律进行了研究。结果表明:热轧试样的组织与织构在厚度方向上呈现明显的梯度变化,试样的表层和过渡层发生再结晶,过渡层存在较强的Goss织构,中心层存在以{001}<110>为主的强α织构。一次冷轧后试样组织被轧制成沿轧向分布的纤维状组织,织构以强α和弱γ织构为主。脱碳退火后试样发生再结晶,晶粒平均尺寸为15.69 μm,总体织构强度有所减弱,但Goss织构强度升高。二次冷轧后组织由等轴晶粒变为纺锤状组织,织构以弱α和强γ织构为主,其中{111}<112>强度最高。     

形变量对6111铝合金再结晶织构的影响

采用取向分布函数(ODF)法研究了冷轧形变量对6111铝合金再结晶织构的影响。结果表明:6111铝合金的再结晶织构主要由Cube ND15和{011}<111>织构组分构成;随冷轧形变量的增加,这两种织构组分的取向密度逐渐升高,但二者升高的速度并不相同,{011}<111>组分取向密度升高的速度比Cube ND15组分的快,当冷轧形变量大约为50%时,{011}<111>组分的取向密度超过Cube ND15组分的。     

390MPa级超低碳BH钢织构演变规律

采用ODF织构分析方法,对390 MPa级超低碳BH钢板热轧、冷轧、退火过程织构演变规律进行研究,并对不同冷轧压下量和不同退火工艺织构进行分析。结果表明:经冷轧变形后的钢板有较强的择优取向,具有典型的{112}<110>和{111}<110>织构,形变织构中的不利织构{001}<110>较强;冷轧压下率为80%时再结晶退火后钢板具有较强的γ织构,{111}<112>织构取向密度高达11.7;退火温度和保温时间对α织构影响不大,提高退火温度和延长保温时间使γ织构增强,r值增加。     

Prediction of inhomogeneous texture in clad sheet metals by hot roll bond method

A finite element analysis was applied to analyze the evolution of an inhomogeneity of rolling texture in hot rolled clad metal with Taylor-Bishop-Hill model and Renourd-Winterberger method. The shear texture has been developed in the surface layer of the aluminum and plane strain texture has been developed in the center layer. The calculated texture variations through thickness direction could simulate experimental texture using deformation gradient from FEM. The ratio of shear strain to rolling strain, x, which represents the degree of rotation about transverse direction could give the degree of development of shear texture. The larger value of x gives the larger crystal rotation about transverse direction and subsequently the development of shear texture. The calculated (111) pole figures were in good agreement with experimentally measured pole figures.     

Analysis of deformation textures of asymmetrically rolled aluminum sheets

Asymmetric rolling, in which the circumferential velocities of working rolls are different, imposes shear deformation and in turn shear deformation textures to sheets through the thickness. A component of ND//〈111〉 in the shear deformation textures can improve the plastic strain ratios of aluminum sheets. In order to understand the evolution of ND//〈111〉, the strain histories and distributions in the sheets and the texture evolution during the asymmetric rolling have been measured and calculated. The shear deformation texture can vary with the ratio of shear to normal strain increments. As the ratio increases from zero to infinity, the texture moves from the plane strain compression texture (β fiber) to the ideal shear deformation texture consisting of {001}〈110〉, {111}〈110〉, and {111}〈112〉. The ratio increases with rolling reduction per pass in asymmetric rolling. However, it is practically difficult to develop a rolling reduction per pass high enough to obtain the ideal shear deformation texture. Imposing the positive and negative shear deformations on the sheet by reversal of the shearing direction can give rise to the ideal shear deformation texture.     

Texture Evolution in an Al-Cu-Mg Alloy During Hot Rolling

The texture evolution in the intermediate (the 1/4 thickness) layer of hot-rolled Al-Cu-Mg alloy sheets was investigated by the x-ray diffraction technique, electron backscattered diffraction analysis and transmission electron microscopy observation. The results showed that a texture transition from the shear texture {001}<110> to the β-fiber textures occurred as the rolling temperature increased to 420 °C. The shear strain caused by friction resulted in this strong shear texture formation at the low rolling temperature. As the rolling temperature increased, the plane strain substituting the shear strain dominated in the intermediate layer, giving rise to a significant increase in the β-fiber textures. Increasing the rolling temperature was found to preferentially activate the non-octahedral {112}<110> slip system, thereby benefiting the development of strong Brass. At the low rolling reduction of 74%, the textures with low intensity tended to converge on the α-fiber, containing Goss, Brass, P and L components. As the rolling reduction increased to 90%, the textures were strengthened and gradually flew toward the β-fiber, containing Brass, Copper and S components. The S and Copper bands were found to be the preferential sites for the development of recrystallizing Cube grains during hot rolling.     

EFFECT OF CHEMICAL COMPOSITION AND PROCESSES ON THE TEXTURE OF HOT-ROLLED DEEP DRAWING STEEL SHEET

1．IntroductionHotrolled deep drawing steels have been developing to partially replace cold－rolleddeep drawing steels to ma协 automobile parts for reducing cost In Industry these years．In general,beneficial texture{111}for deep dr。ability wajs formed I     

Large strain deformation of Ni3Al+B: Part II. Microstructure and texture evolution during recrystallization

The microstructure evolution and texture development of the intermetallic compound Ni₇₆Al₂₄, doped with minor additions of boron, was investigated during annealing subsequent to cold-rolling. Upon annealing of cold-rolled specimens, a hardness increase prior to recrystallization was observed. This is attributed to a relaxation process of the dislocation cores during annealing. Recrystallization proceeded with very different kinetics locally and a very small recrystallized grain size was obtained. From grain growth kinetics, the activation energy for grain boundary motion was found to be close to the activation energy for self-diffusion of Ni in Ni₃Al. The recrystallization texture was almost random. However, three texture components could be invariably recognized ({013}100, {012}021 and {112}294). They are related by special orientation relationships to the brass rolling orientation. A high frequency of annealing twins occurred in the recrystallized microstructure. The misorientation distribution function (MODF) shows a preference of certain low Σ boundaries, namely small-angle boundaries (Σ1) and twins (Σ3).     

横轧3105铝合金织构演变的定量分析

采用X射线衍射仪研究3105铝合金在横轧过程中织构的演变.结果表明:3105铝合金热轧板材具有强的β纤维轧制织构,在横轧过程中B'{110}<111>、S"{123}<17229>和C"{112}<110>取向是不稳定的,它们将逐渐向新的坐标系中β纤维的位置旋转;随横轧压下量增大,C(和S(取向强度快速降低,B(取向强度先增加后降低,而β纤维轧制织构的强度逐渐增加;β纤维和剩余组分织构体积分数的变化与轧制真应变的关系遵循Avrami方程,强的初始B'、S"和C"织构显著地提高了β纤维织构的形成速率.     

Textures variation of 3104 aluminum alloy sheets under different rolling conditions

1　INTRODUCTIONLargequantityoftheAl Mn Mgalloy 310 4isusedinthemanufactureofaluminumbeverage .Muchattentionwaspaidtothecontroloftextureandearinginthedeepdrawingstagesofmanufacture .Thetex tureinthecanstockwasextensivelyinvestigated .Oneearingofaluminumalloyisverycloserelatedtothetexture ,agoodassociationofthetexturescompo nentsearingdropsobviously ,inthissituationthe 4 foldearingat 0°/90°andearingat± 4 5°occursto gether[15] .Theappearanceof 4 foldearingat 0°/90°isduetothecubetext…     

{411}<148> Texture in Thin-Gauge Grain-Oriented Silicon Steel

The significant occupancy of {411}148texture exists in the thin-gauge grain-oriented silicon steel(TGCRGO is defined that thickness of the sheet is0.25 mm and the reduction in cold rolling is more than 90%) which has been considered to have obviously effects on the abnormal growth of Goss-oriented grains during the secondary recrystallization process. The microstructures of the TG-CRGO were investigated by X-ray diffraction and electron back-scattered diffraction in this study. It was found that {411}148texture mainly exists in the center layer of hot-rolled as well as normalized plates.With the increase in cold rolling reduction, {411}148 orientation gradually rotates to a-fiber texture(110//RD).Finally, few {411}148would retain at the boundaries of deformed a-fiber grains(110//RD) as the reduction in cold rolling reaches 90%. After annealing treatment, a small amount of c-fiber textures(111//ND) preferably nucleates and recrystallizes between the DBs(deformation bands) at first; then, the {411}148 recrystallization texture occurs and mainly nucleates at the grains boundaries of the deformed a-fiber grains, and also quite a few {411}148orientation grains nucleate in the inner of {112}110grains. But this phenomenon was not observed in the {100}011deformation grains.With respect to the occurrence of {411}148recrystallization texture, it is mainly induced by strong a-fiber as well as weak c-fiber textures formed during cold rolling other than originating from {411}148 regions in hot bands.     

Effect of tensile deformation rate on texture formation during subsequent rolling and recrystallization of electric steel

The paper deals with the study of the dependence of the number of the main components of the primary recrystallization texture on the deformation rate during uniaxial tension (with contraction) carried out before the cold rolling of an electric steel (bcc soft magnetic alloy Fe-3 wt % Si) stripe up to its final thickness. It is found that the maximum increase in the volume shares of the auspicious components {111}??112??, {112}??351??, and {113}??361?? in the primary recrystallization texture occurs during tension with a minimal deformation rate in the range of 0.00015?C1.10 s^?1.