Nb、Ti对铁素体不锈钢铸态及热轧态组织、织构的影响

研究了不同Nb、Ti添加情况下铁素体不锈钢的铸坯组织特征以及热轧后板材的组织和织构.研究结果表明:Nb的添加可以明显细化铸坯组织,而Nb、Ti双稳定元素的添加强烈地促进了铸坯组织晶粒的等轴化和晶粒细化.Nb、Ti元素的加入不仅可以细化铸坯组织,同时也可以细化热轧后的板材组织,单独添加的Nb、Ti元素均可以推迟板材的再结晶过程,Ti的作用更为明显,而Nb、Ti的同时加入可明显推迟板材的再结晶过程.     

退火工艺对冷轧纯钛带再结晶织构的影响

研究了退火工艺对冷轧纯钛带再结晶织构和屈服强度的影响,并讨论了保温时间、再结晶织构及屈服强度三者之间的关系.结果表明,在650℃下,冷轧纯钛带退火后的再结晶织构主要是(0001)[2110]和(0001)[5610],遗传了纯钛带的冷轧织构.随退火保温时间的延长,织构的取向梯度均逐渐减小,组分和强度趋于稳定,且退火后纯钛带的屈服强度也比较均一,为冷轧纯钛带的生产提供了理论依据.     

电工钢中黄铜织构行为及其对Goss织构的影响

本文通过EBSD取向成像技术检测追踪了取向硅钢热轧、脱碳退火及二次再结晶过程中黄铜取向晶粒的形成规律.结果表明,黄铜取向的形成是热轧时Goss取向在剪切力作用下向铜型取向转动受阻而绕法向转动的结果.与Goss晶粒和{111}〈112〉取向晶粒类似,黄铜取向和{111}〈110〉取向晶粒之间存在形变与再结晶相互转化的密切关系;二次再结晶时若抑制剂钉扎控制不当,在次表层的Goss晶粒快速长入中心层之前,黄铜取向晶粒已长成大尺寸并接触样品表面,随后的Goss大晶粒就很难吞并黄铜取向晶粒.     

工业纯钛板材的轧制织构及微观组织对其孪晶和再结晶行为的依赖性

将工业纯钛(CP-Ti)板轧制至不同程度,随后进行退火以及进行20％的再轧制.通过电子背散射衍射(EBSD)对合金微观组织的变化进行表征.重新轧制后,{11(2)2}＜(1)(1)23＞压缩孪晶和{10(1)2}＜10(1)1＞拉伸孪晶产生.可以观察到孪晶的层状结构,这是由变形孪晶的缠结以及二次和三次孪晶的产生引起的....     

退火工艺对镍基带中立方织构形成的影响

应用电子背散射衍射(EBSD)技术研究退火工艺(单步法和两步法)对形变量为99%的镍基带中立方织构形成的影响.结果表明,随着退火温度的升高,镍基带中立方取向和其它取向的晶粒平均尺寸不断增加,立方取向晶粒的平均尺寸比其它取向晶粒的平均尺寸要大,而且随着退火温度的升高,这种晶粒尺寸优势不断的增加;低温退火时退火工艺对立方织构含量影响不明显,而高温退火时其立方织构含量大幅增加;相对于单步退火法,两步退火法能有效的提高镍基带中立方织构的含量.     

Ce对铝箔再结晶织构演变规律的影响

以高纯铝箔和不同Ce含量的稀土铝箔为研究对象,运用EBSD技术对高纯铝箔与稀土铝箔冷轧后及不同温度再结晶退火后的织构进行分析,研究再结晶退火过程中织构的演变规律和稀土Ce对铝箔织构的影响。结果表明:轧制总变形率为96%的铝箔,织构以铜型织构、R型织构和一些S织构为主。随最终退火温度的升高,立方织构占有率快速增长。少量稀土元素的加入有利于再结晶退火后立方织构的形成。     

冷轧Q值对TA34钛合金管材性能和织构的影响

采用X射线衍射法测定了TA34钛合金管材经不同Q值冷轧后的宏观形变织构和退火织构,分析了冷轧Q值对管材织构、工艺性能和室温力学性能的影响。结果表明：冷轧Q值对管材的塑性影响不大;冷轧TA34钛合金管材形变织构和退火织构的总体类型相同,均为轴向■织构;提高冷轧Q值会使完全再结晶退火后的TA34钛合金管坯产生周向织构,有助于提高成品管材的压扁工艺性能。     

冷轧压下率影响工业纯铝板退火织构变化的EBSD研究

采用电子背散射衍射分析方法,研究了34.7%和79.2%两种压下率对1060(L2)冷轧工业纯铝板退火期间织构演变过程的影响。结果表明,两种试验板冷轧织构均由β取向线的S、Brass和Copper织构组成,它们的体积分数随压下率降低而减小;两种试验板退火织构主要呈现为Cube织构组分增强和β取向线织构组分减弱的演变规律,且变化趋势随压下率增大而加强;在压下率为34.7%所对应的试验板中,Goss及其附近取向的晶粒主要发生了回复和被吞噬的现象,最终退火组织中取向差为60°的大角度晶粒数量较多。     

电场退火对工业纯锌板再结晶织构的影响

利用X射线衍射的三维取向分布函数,研究工业纯锌板在160℃时电场与非电场退火保温不同时间条件下的再结晶织构的形成与演变,同时进行显微硬度测试。结果表明：电场退火推迟轧制工业纯锌板再结晶进程,从而导致电场退火样品的显微硬度值均高于非电场退火样品的显微硬度值。电场显著提高退火后样品的再结晶织构强度,即电场明显促进冷轧{101 8}面织构向再结晶{101 3}〈101 1〉板织构的演变,而且这种影响在再结晶晶粒的长大阶段表现得尤为突出。电场并没有改变工业纯锌板退火过程中再结晶织构的形成机制。     

常化工艺对高牌号无取向硅钢组织和织构的影响

以Si质量分数为3.3%的高牌号无取向硅钢为研究对象,研究了常化处理对试验钢厚度方向组织和织构的影响。结果表明：高牌号无取向硅钢热轧板沿厚度方向组织及织构不均匀导致常化板沿厚度方向出现织构梯度;常化处理可以明显改善热轧板组织和织构,促进晶粒粗大均匀,降低α纤维织构强度,增强λ纤维织构强度,减弱γ纤维织构强度。950 ℃常化时,常化板沿厚度方向晶粒粗大均匀,λ纤维织构强度最大。     

冷轧板再结晶退火中组织和织构演变的研究

薄板坯连铸连轧(CSP)热轧板料经热处理来适当调整组织后进行冷轧及退火,并运用电子背散射衍射(EBSD)技术研究了再结晶退火中组织和织构的演变.结果表明:发生再结晶的温度范围是530℃～590℃,590℃为完全再结晶温度;再结晶发生时冷轧变形基体和新晶粒取向的晶界角度差大约为25°～55°;{111}〈110〉、{111}〈112〉取向在再结晶初期和中期发生很大的变化,而{001}〈110〉、{112}〈110〉取向在再结晶后期才发生很大的变化;EBSD检测的结果分析可得{001}〈110〉、{112}〈110〉、{111}面取向储存的变形能依次增加.     

Microstructure and textural evolution during cold rolling and annealing of commercially pure titanium sheet

The effects of cold rolling and annealing on the microstructure and textural evolution of a commercially pure titanium (CP-Ti) sheet were investigated. Electron backscatter diffractometry demonstrates that the deformation during rolling is accommodated by twinning and slip. Additionally, twinning is the dominant deformation mechanism when the cold rolling reduction is less than 40%. During rolling, $\left\{11\overline{2}2\right\}〈11\overline{2}\overline{3}〉$ contraction twinning (CT) and $\left\{10\overline{1}2\right\}〈10\overline{1}1〉$ extension twinning (ET) are activated. And, the intensity of the (0002) pole along the ND gradually increases with increasing deformation. During annealing, the fraction of low angle grain boundaries (LAGBs) and the intensity of the (0002) pole along the ND gradually decrease slightly with increasing annealing time, while twinning lamellae disappear rapidly. When the annealing time reaches 60 min, 20% cold-rolled sheet recrystallizes almost completely.     

冷轧形变量和退火温度对Cu-44%Ni 合金的微观组织及织构演变的影响

研究了冷轧变形量和退火温度对Cu-44%Ni合金中立方织构的形成及微观组织演变的影响。结果表明增大变形量和提高退火温度均有利于立方织构的形成,而且在变形量大于90%和退火温度高于900 ℃的条件下,可以得到非常强的立方织构。另一方面,随着变形量的增加,退火孪晶(Σ3晶界)和大角度晶界降低;但是在等温退火中,随着退火温度的增加,Σ3晶界和大角度晶界先迅速的增加,然后逐渐减少。冷轧变形量99%的Cu-44%Ni 合金在1100 ℃高温退火1h后可以获得了99.8%的立方织构,并且大角度晶界和退火孪晶界分别为2.5%和1.3%。     

冷轧方式和退火温度对Al-4Cu-0.73Mg合金织构和微观组织的影响

采用硬度测试、X射线衍射(XRD)、电子背散射衍射(EBSD)等方法研究了单向轧制、交叉轧制和退火温度对Al-4Cu-0.73Mg(wt%)合金织构演变和微观组织的影响。结果表明:单向轧制试样在100~300 ℃退火保温1 h后显示出明显的Copper织构{112} <111>、S织构{123} <634>和Brass织构{011}<211>,而交叉轧制试样表现出强烈的Brass织构和H织构{011}<755>。当退火温度高于300 ℃,单向轧制和交叉轧制试样中的变形织构逐渐沿α取向线转变为由P织构{011}<001>、L织构{011}<011>、E织构{111}<110>和R织构{124}<211>等组成的再结晶织构。单向轧制和交叉轧制试样的晶粒尺寸随退火温度的升高先增加后减小,均在350 ℃退火1 h后有最大晶粒尺寸,分别约为8.2 μm和11.5 μm。单向轧制和交叉轧制试样均在冷轧后硬度值最高,约为108 HV,之后硬度值随退火温度的升高而逐渐下降,两种轧制试样的硬度值最终均稳定在50 HV左右。总体来看,轧制方式对试样织构的影响比对力学性能的影响大。     

冷轧TA5钛合金退火过程的再结晶行为及织构演变

采用电子背散射衍射技术(EBSD)对冷轧及退火态TA5钛合金板材的晶粒尺寸、再结晶及织构进行了表征,并讨论了变形不均匀对再结晶行为及织构演变的影响。结果表明:<0002>//TD取向晶粒比<0002>//ND取向晶粒更容易发生变形,结合hcp结构滑移系统的有限性,共同决定了TA5合金板材冷轧变形具有不均匀性的特点。退火早期再结晶在局部应变大的区域快速形核,且变形量越大,形核数量也越多,再结晶后样品的晶粒尺寸也越小。局部应变大的区域在退火早期以“定向形核”机制快速发生再结晶形核并长大,包括少量剩余的严重变形<0002>//TD取向晶粒;同时,其余应变较低的组织在再结晶形核全过程以“应变诱发晶界迁动形核”机制缓慢形核,这两种机制共同作用导致退火后板材的织构弱化,但仍以冷轧态的基面织构为主。硬度变化曲线可以很好的反映再结晶程度;但受织构影响,不同测试面的硬度值存在显著差异,加载轴与晶体c轴之间的夹角越大,硬度值越小。     

热轧组织对冷轧无取向硅钢退火织构及组织的影响

对不同加热温度处理的热轧低硅钢带进行了冷轧及退火实验,分析了热轧钢带的组织对冷轧无取向硅钢再结晶退火过程中的组织及织构的影响。结果表明:热轧组织对冷轧无取向电工钢冷轧板再结晶组织及织构演变有重要影响;等轴晶粒组织的热轧钢带比混晶组织的热轧钢带冷轧后再结晶退火快,且退火后晶粒尺寸均匀;随着等轴晶粒尺寸增加,冷轧退火后形成的冷轧硅钢{110}类型的织构增强,{100}类型的织构减弱;表明热轧组织为等轴晶粒时,不利于冷轧无取向硅钢磁性能的改善。     

Effect of strain path change on the through-thickness microstructure during tantalum rolling

High purity tantalum was respectively processed by unidirectional rolling (UR) and clock rolling (CR), and the through-thickness microstructures were investigated by multiple characterization techniques including electron backscatter diffraction (EBSD), Vickers hardness (HV) and X-ray diffraction (XRD). Results show that the through-thickness stored energy distribution in CR specimens is more homogeneous than in UR specimens due to uniform texture distribution. {111} grains possess larger Schmid factors and the corresponding Schmid factor difference ratio than {100} grains, indicating the activation of uniserial slipping in {111} grains, which leads to inhomogeneous deformation and higher stored energy. Besides, X-ray line profile analysis (XLPA) suggests that the stored energy of {111} grains increases successively from the surface to center layer, regardless of strain paths, due to the influence of redundant friction on the surface layers. While the occurrence of multiple slipping in {100} grains leads to homogeneous deformation and lower stored energy.     

低碳钢板冷轧退火组织和织构

分别采用基于薄板坯连铸连轧(CSP)工艺和传统热连轧工艺条件下的低碳钢板作为冷轧基料,在实验室模拟现场工艺进行了冷轧和退火。通过金相观察和X射线衍射织构分析,比较了两种工艺下低碳钢板的组织和织构演变的规律。结果表明:两种试样冷轧后α取向线上显著增加的织构有较大的区别,CSP工艺下是{001}〈110〉,而传统工艺下是{112}〈110〉;在同样的冷轧及退火工艺条件下,CSP条件下的钢板在退火过程中发生再结晶需要的温度更高,时间更长;对于CSP钢板,退火对γ取向线的影响要大于冷轧对其的影响,而对于传统热连轧钢板,冷轧和退火过程对γ取向线都有比较大的影响。     

Comparison of equal channel angular pressing and cold rolling in the evolution of microstructure and texture in zirconium

Evolution characteristics of the microstructure and texture of severely deformed commercial purity Zr702 were studied. The mode of the severe deformation was either heavy cold rolling or equal channel angular (ECA) pressing. Equiaxed grains, present prior to the deformation, became elongated during deformation along the rolling direction or along the maximum shear direction for the case of cold rolling or that of ECA pressing, respectively. ECA pressing transformed the initial fiber texture to a quite different component, which was also the case for cold rolling. In both cases, the maximum intensity of texture increased with the amount of deformation. Complete recrystallization was realized upon subsequent heat treatment lasting 100 min. at 600°C, and the evolution characteristics of texture and microstructure were also similar for both modes of deformation. These similarities in the microstructure and texture were attributed to the particular route of ECA pressing employed in the present study, i.e., route A. It is therefore concluded that the deformation and annealing behaviors in this particular route of ECA pressing are essentially very close to those of cold rolling.     

Evaluation of microstructure and texture formation during annealing of cold-rolled FeCrCuMnNi multiphase high-entropy alloy

Microstructure and texture variations of a cold-rolled multiphase FeCrCuMnNi high-entropy alloy were studied after different annealing treatments. Samples were heat-treated at different temperatures and for different time, and then, subjected to different tests including XRD and SEM-EBSD. The results reveal that the FCC1 phase, which goes through more strain, has lower melting temperature, and recrystallizes earlier (lower temperature and shorter time). In addition, it is seen that particle stimulated nucleation is more effective on the recrystallization of this phase compared to FCC2 phase. A significant number of FCC1 nuclei form around the BCC particles. Nucleation of FCC2 phase initiated at 800 °C mostly at the grain boundaries and the inhomogeneities. The FCC1 phase was almost fully recrystallized at this temperature. The annealing process led to the elimination of rolling textures, while the Brass component remained a major component in the recrystallized samples. Increasing annealing temperature as well as annealing time led to the formation of Cube texture component, which is a major component of recrystallized low stacking fault energy materials. Furthermore, D and Rt-Co components formed during recrystallization as a result of the formation of annealing twins.