柱状晶对Fe-3%Si电工钢再结晶织构演变规律的影响

在对长轴分别平行于板法向(ND)、轧向(RD)、横向(TD)的柱状晶样品冷轧组织及织构演变规律分析的基础上,利用XRD与EBSD技术,对不同退火温度下各样品再结晶织构的形成规律进行分析.结果表明,柱状晶样品再结晶织构的演变,一方面体现了初始取向晶粒的"遗传性",即立方织构与Goss织构的形成;另一方面又展示了柱状晶样品不同于单晶及多晶的"特殊性",即{113}织构的形成、Goss晶粒大大超过立方晶粒的生长能力及TD样品中{110}〈110〉取向晶粒的消失.退火温度的变化在不同样品中可造成立方织构的增强或减弱,这取决于再结晶时的形核及长大环境,分析认为TD样品低温时形成最强的立方织构与其在冷轧过程中最强的晶界阻力有关.综合考虑各再结晶织构的转变规律,其形成与定向形核及定向长大均相关.研究还证实,3种柱状晶样品中等压下量冷轧并退火后都可抑制γ线织构的形成.     

电工钢柱状晶热、冷轧时晶界作用分析

利用XRD和EBSD研究了长轴分别平行于轧向(RD)、横向(TD)和轧面法向(ND)的柱状晶样品在热轧、冷轧及退火过程中的组织、织构演变规律,并分别从几何诱导和取向诱导两个方面分析了晶界的交互作用.结果表明,热轧时由表面摩擦剪切作用引起的组织和织构梯度直接影响并遗传给后续冷轧及退火样品.热轧后,不同样品的初始晶粒形状各向异性差异消失,形成相同的各向异性晶界组织,但晶体学各向异性发生改变,导致随后冷轧、退火组织及织构的变化均不同于直接冷轧的柱状晶样品.研究中特别关注了对磁性能有利的{100}取向区域与晶界的关系.     

3104铝合金固溶及时效处理后的冷轧织构

应用取向分布函数（ODF）研究了3104铝合金经不同温度固溶及时效处理后的冷轧织构组态。结果表明：经固溶时效处理后其冷轧织构中存在强度较高的旋转立方织构v{001}〈110〉组分,此外也含有一定强度的c{112}〈111〉、B{110}〈112〉和S{123}〈634〉织构组分,明显不同于未经固溶时效直接冷轧样品的织构组态特征。可能的原因是经固溶和时效处理后溶质原子和析出相粒子形态和数量的变化,它们在变形过程阻碍了位错滑移,使晶粒转动受阻,进而使不稳定取向旋转立方织构被不同程度的保留下来;此外,固溶温度越高,冷轧样品中不稳定取向旋转立方织构组分取向密度越小,时效温度对后继冷轧织构的影响也应归结为析出相粒子在变形过程中对位错滑移的阻碍,进而影响晶粒转动。     

预先热处理对6111铝合金冷轧及再结晶织构的影响

采用取向分布函数(ODF)法研究了预先热处理对6111铝合金的冷轧和再结晶织构组态的影响。结果表明:预先热处理因改变基体的成分和第二相的析出状态而显著影响6111铝合金的形变织构和再结晶织构;热轧板不经预处理而直接冷轧,其再结晶织构主要由绕法向旋转了15°的立方取向(Cube ND15)和{011}〈111〉取向构成;冷轧前进行过时效处理,其再结晶织构主要由绕法向旋转了20°的立方取向(Cube ND20)和{011}〈122〉取向构成;冷轧前进行固溶处理会显著提高冷轧织构中Brass和Goss组分的取向密度,再结晶织构明显弱化,而且Cube ND20组分绕法方向(ND)产生很大的漫散,接近于{001}〈UVW〉纤维织构。     

Fe-3%Si电工钢铸坯柱状晶织构的演变规律

采用Fe-3%Si电工钢铸坯中长轴平行于轧向的不同数量柱状晶进行了冷变形及再结晶退火,采用EBSD分析技术对柱状晶织构的转变行为进行了研究.结果表明,原始柱状晶为立方取向的单柱状晶时,大压下率一次冷轧及再结晶退火不利于立方织构的保留;小压下率二次冷轧及再结晶退火会形成强立方织构,该立方织构强烈阻碍Goss晶粒的异常长大;原始柱状晶为立方和Goss位向的双柱状晶时,大压下率冷轧条件下,Goss取向快速转向{111}112而有效地保留了立方取向,Goss和立方取向柱状晶之间的晶界没有强的交互作用;原始柱状晶为多种位向的多柱状晶时,柱状晶晶界能促进g织构及减少立方织构,有利于Goss晶粒异常长大.     

电真空用冷轧钼薄板晶粒取向与力学性能分析

利用EBSD和金相分析了电真空用0.5mm厚冷轧退火钼薄板的晶粒取向及显微组织,并探讨其与力学性能的关联性。结果表明,加工性能优异的钼薄板中晶粒取向分布相对较弱、较漫散,主要包含α线和γ线织构,其中α线织构的最大组分为旋转立方{001}<110>,并含有一定量{112}<110>;晶粒多为沿RD方向且平行轧面顺序排列的“扁云片”状;有相对较少的θ＞50°大角度晶界;这使得RD、TD及45°-RD方向的屈强比和延伸率均较高,延伸率各向异性较低,强塑性匹配良好。     

铁硅合金轧制-退火过程中立方取向晶粒的形核与长大

利用金相显微镜和EBSD技术分析研究了Fe-3.2%Si合金二次冷轧织构、(100)[001]立方取向晶粒形核、初次再结晶以及二次再结晶后立方织构的形成。结果表明,二次冷轧之后的织构主要为{111}<112>和{111}<011>,并存在少量的{112}<110>,同时在变形晶粒内部存在有接近{100}<001>取向的微区。冷变形晶粒内部各微区取向连续变化,并且逐渐向近立方取向靠近。冷变形晶粒内部立方取向的微区作为形核的核心,在退火过程中利用(100)晶粒低表面能和γ→α相变最终发展成为具有集中立方织构的柱状晶组织。     

1.3%Si无取向硅钢初始织构遗传继承性研究

选取工业生产1.3%Si无取向硅钢连铸坯柱状晶区域铸锭,垂直于柱状晶的生长方向(100方向)进行热轧,利用金相及EBSD技术研究其热轧过程中柱状晶被破碎后的组织及微观织构,同时研究了其在后续冷轧和退火阶段的织构演变规律,为实际生产中的织构控制提供了参考。实验结果表明:经垂直于柱状晶生长方向热轧后,热轧板不同层次的主要织构类型和含量存在差异;热轧板次表层主要为铜型{110}112织构和高斯{110}001织构,高斯织构含量较高是100生长方向的柱状晶造成的;表面至心部1/2层主要为γ纤维织构和旋转立方{100}110织构,立方{100}001织构和高斯织构{110}001织构也较多;中心层织构主要为较强的旋转立方{100}110织构和γ纤维织构;冷轧织构与热轧织构间有继承性,冷轧板织构主要为较强的旋转立方{100}110织构γ织构,与热轧板心层织构分布相同,上述两类织构的含量都比热轧板中的高。退火织构中{111}121织构占优势;立方{100}001织构和{111}110织构含量较高。     

3104铝合金冷轧变形织构的分析

通过对3104铝合金冷轧板的三维取向分布函数(ODF)的测算,研究和分析了该材料的织构类型与分布规律。结果表明:在冷轧过程中,所有样品的冷轧织构表现为典型的铜式(Copper-type)织构特征,其织构组分为C{112}〈111〉+B{110}〈112〉+S{123}〈634〉,随变形量的增加,织构由弱到强,最后稳定在铜织构C、黄铜织构B和S织构三个织构组分;{100}〈001〉立方织构在冷轧板中含量较弱,不足以与轧制织构相平衡。     

冷轧压下率对连续退火Ti-IF钢组织和深冲性能的影响

以工业生产的Ti-IF钢热轧板为研究材料,结合连续热镀锌线的工艺特点,采用实验室冷轧、盐浴退火方法和金相、X射线织构测试和力学性能检测等分析手段,研究了冷轧压下率对组织、织构和深冲性能的影响规律。试验结果表明,随着冷轧压下率从60%提高到90%,冷轧态α取向线上的取向密度不断增强,主要形成了{223}〈110〉和{114}〈110〉织构,γ取向线上的{111}〈011〉和{111}〈112〉织构亦有所增强;退火后铁素体晶粒尺寸从9.0级细化到10.5级,导致强度(特别是屈服强度)有所增加,η_(90°)值有所降低。试验钢退火后仍具有较强的{223}〈110〉和{114}〈110〉织构,此外,随着冷轧压下率从60%提高到80%,{111}〈110〉和{111}〈112〉织构有增强的趋势,且{111}〈110〉织构比{111}〈112〉织构强,r_(90°)值有所提高;当冷轧压下率进一步提高到90%时,{111}〈112〉织构明显增强,但{111}〈110〉织构变化较小,导致{111}〈112〉织构比{111}〈110〉织构强,使r_(90°)值反而有所降低,这与γ织构分布变化导致制耳分布曲线由典型的4制耳特征转变为6制耳特征有关。     

Phase Transformation and Texture Evolution During Cold Rolling and alpha '-M Reversion in High Manganese TRIP SteelEI北大核心CSCD

To meet the requirement of environment, economy and safety, advanced high strength steels including dual phased (DP), complex phased (CP), transformation- induced plasticity (TRIP) and twinning-induced plasticity (TWIP) steels are widely used for automotive steel. Among them, high manganese TWIP and TRIP steels are particularly appealing due to their outstanding tensile strength and elongation. In contrast to high manganese TWIP steel, high manganese TRIP steel exhibits higher strength and work hardening rate due to strain induced martensitic transformation. The enhanced mechanical properties of high manganese TRIP steel are determined by both the stability of the retained austenite (gamma) and the initial microstructure. Strain induced martensitic transformation and subsequent reversion from deformed martensite to gamma during annealing is often applied as one of the most effective methods for microstructure improvement. Microstructure and texture characteristics of high manganese TRIP steel during cold rolling together with the reversion of deformed bcc martensite (alpha'-M) at high temperature were investigated. It is shown that the gamma was almost completely transformed into alpha'-M at medium cold rolling reduction. And a higher reduction after alpha'-M saturation resulted in dominantly the deformation of alpha'-M, hence thin laths paralleled to the rolling direction (RD) were obtained. The main components in alpha'-M were {113}< 110 >, {554}< 225 > and rotated cube ({001}< 110 >) textures at medium cold rolling reduction, which are the typical phase transformation textures. The {113}<110> texture rotated toward a more stable orientation {223}< 110 > and led to a strong cold rolling texture (< 110 >//RD) with increasing reduction. The reversion of martensite and recrystallization of gamma proceeded at temperature ranging from 650 degrees C to 850 degrees C. The reversion of alpha'-M proceeded in a diffusional mechanism, accompanying with the redistribution of Mn and Al between gamma and alpha'-M. Deformed alpha'-M was merged by the adjacent gamma, and columnar gamma grains with a large amount of subgrains were obtained. The texture of reverted gamma was approximately the same as that of the deformed gamma, this phenomenon called texture inheritance was formed by the direct growth of gamma. Subsequently, recrystallization of gamma grains occurred by sub-grain coalescence and the columnar g grains were instead by equiaxed gamma grains.     

横轧3 104铝合金变形织构的研究

应用极图分析及织构定量计算的方法，研究了横轧对3104铝合金变形织构的影响，结果表明：在与常规轧制相同压下量的横向轧制下，3104铝合金中的｛112｝，｛213｝丝织构体积百分数均低于常规轧制时各组分的体积百分数，而横向轧制则使得｛102｝丝织构增加较多，在横向轧制过程中出现强旋转立方织构和新｛110｝＜557＞取向的织构。     

退火过程中无取向电工钢的晶粒长大行为及磁性能演变

对Fe-3%Si无取向电工钢冷轧板进行不同时间的退火处理,利用光学显微镜、EBSD等研究了退火过程的晶粒长大行为及其对磁性能的影响。结果表明,随着退火时间的增加,退火板中Goss以及γ织构晶粒占比降低,{114}<841>以及{001}<120>织构晶粒占比增大。在退火时间低于20 s时,退火织构以强γ和Goss织构为主。退火时间为60 s时,{001}<120>织构晶粒长大速率急剧增大,平均晶粒尺寸达到约105 μm。退火时间达到240 s时,退火织构以强{001}<120>以及{114}<841>织构为主。退火时间为30～60 s时轧向及横向磁感值迅速增大,60 s时轧向磁感达到最大值1.74 T,120 s时横向磁感达到最大值1.67 T,之后随着退火时间增加而轻微降低,并分别稳定在1.72 T和1.66 T左右。退火板45°方向磁感值先升高后降低,20 s时达到最大值1.67 T。各方向的铁损值均随退火时间的增加而降低,且磁各向异性逐渐减小。     

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.     

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。     

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。     

Effects of cross rolling on texture,mechanical properties and anisotropy of pure Mo plates

To clarify the influence of the deformation texture on the mechanical properties, pure Mo plates were processed by various cross rolling procedures, and the relation among texture, microstructure and mechanical properties was discussed. The results show that cross rolling of the Mo plates is beneficial for the formation of the rotated cube component, i.e., {001}〈110〉. The corresponding orientation density exhibits a positive correlation with the total rolling deformation and the current-pass deformation. When the total deformation is 96% or greater, the Mo plates form a texture orientation dominated by {001}〈110〉, whereas the γ-fibre texture becomes weaker and the cube texture {100}〈100〉 disappears completely. The presence of {001}〈110〉 has great effects on the properties of cross-rolled Mo plates, which is beneficial for strength enhancement and plasticity reduction in both the rolling direction (RD) and the transverse direction (TD).     

Effect of Asymmetric Hot Rolling on the Texture Evolution of Fe–3%Si Steel

In Fe–3%Si steel, the hot rolling process affects not only the hot rolling texture but also the primary recrystallization texture. Here, the effect of asymmetric hot rolling was studied by comparing the difference in the texture evolved between asymmetric and symmetric hot rolling. The effect of asymmetric hot rolling on the texture of primary recrystallized Fe–3%Si steel was also studied. The symmetric hot rolling of Fe–3%Si steel produces a rotated cube texture at the center but Goss and copper textures near the surface. Asymmetric hot rolling tends to produce Goss and copper textures even at the center like the texture near the surface. After primary recrystallization, the dominant texture at the center changes from {001} <210> to {111} <112> and the new texture has a higher fraction of the grains which make the low energy boundary with Goss grains than that of symmetric hot rolling.