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 α-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 α-fiber and weak γ-fiber textures were formed; the cold rolled textures were comprised of sharp α-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 α-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 α-fiber, resulting in the formation of a nearly homogeneous γ-fiber recrystallization texture in the center layer of the final sheet.     

冷轧过程中IF钢板织构的ODF分析

采用ODF分析方法,对IF钢热轧钢板在冷轧过程中织构变化进行了分析.结果指出,随冷轧压下量的增加,钢板中晶粒的取向密度主要汇集于α、γ取向线附近,织构的变化也主要表现在α、γ取向线的{001}<110>、{112}<111>、{111}<110>、{111}取向密度的增加上.其趋势是随形变量的增加,{111}<110>、{111}织构增加幅度较大.     

摩擦对IF钢铁素体区热轧和退火织构的影响

采用X射线衍射仪分析IF钢铁素体区热轧织构以及退火织构的演化,在实验室热轧机上进行了IF钢的铁素体区热轧,研究了摩擦对IF钢铁素体区热轧、退火织构的影响。结果表明：无润滑轧制时,钢板表层形成强高斯织构组分{110}〈001〉,弱γ纤维织构,导致再结晶织构中高斯组分强度高,γ纤维织构强度低;润滑轧制时,钢板表层高斯织构组分强度降低,{100}〈011〉、γ纤维织构强度提高,退火后γ纤维织构强度提高。钢板中心受摩擦作用影响较小,轧制过程中发展为较强的α和γ纤维织构,退火后γ纤维织构成为主要织构组分。     

不同冷轧压下量对亚稳态奥氏体不锈钢00Cr17Ni7织构的影响

 采用X射线衍射技术(XRD)研究了不同冷轧压下量对亚稳态奥氏体不锈钢00Cr17Ni7织构的影响,分析了亚稳态奥氏体不锈钢00Cr17Ni7中马氏体相和奥氏体相的织构变化情况。研究结果表明,不同冷轧压下量下,00Cr17Ni7中的奥氏体相织构主要由Brass{110}<112>、Goss{110}<001>和少量的Copper{112}<111>、S{123}<634>组成,并且随着压下量的增加Brass和Goss织构强度显著提高;同时马氏体相织构主要以{115}<110>、{112}<110> 、{111}<112>、{332}<113>组成,织构的形成主要归因于“Kurdjumov-Sachs取向关系”和“体心立方金属轧制织构类型演变的特点”共同作用的结果。     

430不锈钢冷轧板高温退火过程中再结晶织构的定量分析

在750、800、825和850℃温度下,利用Gleeble1500热模拟试验机对430不锈钢冷轧薄板的等温退火过程进行了详细的实验研究,分析了退火过程中再结晶织构和组织的变化规律,并对关键织构体积分数的演变进行了定量分析.结果发现：随着退火过程的进行,α取向线上的织构强度逐渐减弱,而γ取向线上的织构强度则略有加强,并保持在较高的值;再结晶过程中,{111}和{112}<110>织构的体积分数逐渐降低,而{100}和随机取向晶粒的体积分数逐渐增加.定量分析表明,退火温度越低,完全再结晶后材料内部关键织构的体积分数越偏离冷轧态.最后,针对{111}、{112}<110>、{100}和随机取向织构的体积分数在再结晶过程中的演变规律,建立了JMAK型再结晶织构演变动力学模型.     

冷轧工艺对443铁素体不锈钢抗皱性能影响

以443铁素体不锈钢为研究对象,研究了冷轧工艺对其表面抗皱性能的影响.结果表明,冷轧采用二轧程的生产工艺可以明显改善表面抗起皱性能;一轧程冷轧板芯部存在明显的晶粒簇,沿着轧向成条状分布,晶粒呈非等轴状,尺寸偏大,而二轧程冷轧板芯部组织分布均匀;一轧程冷轧板表层和芯部除了γ纤维再结晶外还保留强烈的{112}<110>织构...     

半工艺无取向硅钢加临界变形的织构演变

测定了半工艺无取向电工钢热轧(终轧温度在Ar1以下)到成品各工序的织构,以取向分布函数(ODF)的形式对加临界变形的半工艺无取向硅钢的织构演变作了分析.发现其热轧板表层织构基本是典型的铁素体再结晶{111}组分,心部和1/4厚度处以铁素体剪切织构和轧制变形织构为主.冷轧变形后,心部和表层织构组分比较接近,{111}、{112}和{100}面织构都增加,但{111}组分增加最明显.软化退火后,{001}<110>与{112}<110>组分迅速降低,织构组分以γ纤维织构为主.通过增加临界变形,在最终去应力退火后,{111}不利面织构大量减少,高斯组分增加明显.Taylor因子可以表征不同取向晶粒对变形能的储存能力,从轧制变形时Taylor因子的分布可以解释该实验结果.     

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.     

In-Situ Annealing Study of Transformation of α and γ Texture of Interstitial-Free Steel Sheet by High-Energy X-Ray Diffraction

 High-energy synchrotron diffraction offers great potential for experimental study of recrystallization kinetics. An experimental design to study the recrystallization mechanism of interstitial-free (IF) steel was implemented. The whole annealing process of cold-rolled IF steel with 80% reduction was observed in situ using high-energy X-ray diffraction (HEXRD). The results show how the main texture component of IF steel change, i. e. the α ［<110>∥rolling direction (RD)］ fiber texture decreases and the γ ［<111>∥normal direction (ND)］ fiber texture increases. The important part of the α fiber texture is that both the {100}<011> and {112}<011> texture decrease at the beginning of recrystallization. The γ fiber texture increases at the early stage of recrystallization which stems from the increase of {111}<112>. Nevertheless, the {111}<110> does not change after recrystallization. The dynamic evolution of the main texture components {100}<011>, {112}<011>, {111}<112> and {111}<110> is given by in-situ HEXRD.     

基于CSP工艺稀土冷轧板罩式退火中组织织构演变

 采用金相显微镜和X射线衍射仪对CSP(Compact Strip Production)稀土板热轧、冷轧及退火3个阶段的组织和织构进行了检测和分析,并结合文献讨论了稀土板组织织构的演变规律。结果表明：稀土冷轧板以{223}<110>、{001}<110>、{112}<110>为主要织构,退火后形成了以{223}<110>和{111}<110>为主的再结晶织构,织构密度均达8. 5以上,{223}<110>和{111}<110>取向差为10°。稀土板开始再结晶需要的温度较高,并且再结晶完成需要的时间较长。再结晶初期织构变化比后期小。试验稀土板退火后{111}/{001}值极大,{111}<011>织构与{111}<211>织构密度差约为6。     

Textures and Properties of Hot Rolled High Strength Ti-IF Steels

The texture evolution in a high strength Ti-IF steel during the processing of hot rolling, cold rolling, and annealing is studied. For comparison, both ferrite rolling and austenite rolling are employed. It is found that the texture type is the. same after ferrite rolling and austenite rolling, but the texture intensity is much higher in the ferrite rolled sample. Furthermore, texture characteristics at the surface are absolutely different from those at the mid sec tion in both ferrite rolled and austenite rolled samples, as well as under the cold rolled and annealed conditions. The shear texture { 110 } 〈001 〉 disappears and orientation rotates along { 110 } 〈001 〉→ { 554 } 〈 225 〉→ { 111 } 〈 112 〉→{111}〈110〉→{223}〈110〉 during cold rolling. Compared to the austenite rolled sample, the properties of the cold rolled and annealed sheet which is subjected to ferrite rolling are higher.     

再结晶阶段加热速度对低碳冷轧板罩式退火过程组织和织构的影响

在实验室条件下模拟CSP热轧板为基板生产的低碳冷轧板罩式退火过程,研究再结晶阶段加热速度对冷轧板罩式退火过程组织和织构的影响。结果表明,压下率83.3%的冷轧板,随着再结晶阶段加热速度的增加,会使试样再结晶温度降低,再结晶过程提前完成,{001}110织构变强,{111}110织构先减少后增加,{111}112织构先减少后增加出现峰值,当加热速度超过50℃/h时又减小。在加热速度30~40℃/h间变形织构{112}110有较低的密度值。再结晶阶段加热速度40℃/h的退火工艺成品组织为饼形晶粒,{001}110织构密度较低,{111}110和{111}112密度较强,密度值接近。     

Ti-26Nb-4Zr合金冷轧板材的织构和力学性能

采用X射线衍射和室温拉伸方法研究了冷轧变形和固溶处理对Ti-26Nb-4Zr合金板材的织构和力学性能的影响.研究发现,50%冷轧时形成了{001}〈uvw〉织构,随着冷变形量的增加,逐渐形成了{121}〈1相似文献   

Texture Evolution of Columnar Grains in Electrical Steel During Hot Rolling

Columnar grains in cast slabs of electrical steel show strong anisotropy in grain orientation and morphology and thus influence the subsequent microstructure and texture after hot rolling significantly. The texture evolution of hot rolled sheets containing initial columnar grains with their <100> directions approximately parallel to the rolling direction (RD), transverse direction (TD) and normal direction (ND) of the hot rolled sheets was investigated by using EBSD technique. The results indicated that, whatever the initial texture of the columnar grains was, typical Goss, brass-type and copper-type shear texture component could develop in shear-deformed surface region. The copper-type texture formed under the maximum shearing force with the fine, sheared or dynamically recrystallized grains, and Goss grains were mainly elongated and deformed grains, while brass grains behaved between them. Additionally, the rotating relationship of the three types of shear textures was different due to the restriction of grain boundaries. In homogenously deformed center region, the RD sample contained more {112} <110> grains, and TD sample was covered by {100} textures such as {100}<011> and {100}<021> with coarse grains, while the ND sample developed many {100}<011> grains which were attributed to more {100} grains in the initial sample. Remarkable texture transition occurred on both sides of grain boundaries when {110} grains were adjacent to α-fiber texture grains. It was found that significant texture gradient and preferred distribution of rotating axis existed in the soft orientation grains on the α-fiber when the grains neighbored hard grains on γ-fiber.     

冷轧压下率和再结晶退火温度对Ti-IF钢织构和成型性能的影响

采用背散射衍射技术(EBSD)研究了3.13 mm热轧板的冷轧压下量(65%~80%)和再结晶退火温度(660~780℃)对0.64~1.10 mm Ti-IF钢冷轧板(/%:0.02C、0.01Si、0.10Mn、0.013P、0.011S、0.064 Ti、0.028Al、0.002 0N)的织构和成型性能应变硬化指数(n)、塑性应变比(r)的影响。结果表明,Ti-IF钢冷轧板在冷轧压下率为75%时{111}织构含量最大,成型性能最佳;在740℃以下再结晶退火时材料{111}<110>织构含量高,高于740℃时材料{111}<112>织构含量高;在660~780℃再结晶退火随温度增高,材料{111}织构含量增加,成型性能提高。     

低温板坯加热取向硅钢形变和初次再结晶织构的演变规律

 采用取向分布函数和取向线分析方法对低温板坯加热取向硅钢从热轧到初次再结晶工艺阶段的织构进行了研究。研究表明：一次冷轧后各层的织构组分与热轧板各层面的织构组分存在着继承关系,次表层存在很强的{001}<110>织构,中心层的织构和热轧板的中心层相似,存在强的{001}<110>和{112}<110>织构;中间退火后发生再结晶,各织构组分的强度有所减弱,Goss织构组分再次出现;二次冷轧后沿厚度方向上的织构不均匀性不明显,{111}<112>织构强度最高,几乎是其他织构组分的1倍,{001}<110>织构大幅降低;初次再结晶后织构沿厚度方向没有明显的不均匀性,{111}<110>为最强的织构组分,并且具有一定强度的Goss位向。     

铁素体不锈钢铸轧薄带凝固组织对冷轧退火带晶粒簇的影响

 研究了Cr17铁素体不锈钢铸轧薄带凝固组织对其冷轧退火带晶粒簇、成形性和皱折特性的影响。利用电子背散射衍射技术对Cr17铁素体不锈钢铸轧薄带及相应的冷轧退火带进行了显微织构分析。结果表明：①Cr17铁素体不锈钢铸轧薄带冷轧退火带的晶粒簇依赖于初始铸轧薄带的凝固组织类型;②柱状晶组织的铸轧薄带具有显著的{001}∥ND晶体取向特征,而等轴晶组织的铸轧薄带晶体取向随机、分散;③等轴晶组织铸轧薄带比柱状晶组织铸轧薄带的冷轧退火带具有更少的{001}<110>晶粒簇和更多的{111}<112>、{111}<110>晶粒簇;④铸轧薄带的等轴晶组织比柱状晶组织有利于提高冷轧退火带的成形和抗皱性能。     

一次再结晶法取向硅钢超薄带的冷轧塑性变形行为北大核心CSCD

以市场上购买的取向硅钢成品板为原料,经不同压下率冷轧至0.23~0.08 mm不等。借助X射线衍射仪(XRD)检测了冷轧后样品中的织构组分及其含量,利用电子背散射技术(EBSD)测量了试样的取向因子分布情况。观察了孪晶的形貌与晶体学特征,分析了硅钢超薄带的塑性变形行为。结果发现,在平面压缩应力下,{112}<111>滑移系的取向因子较大。随冷轧压下率的增加,Goss织构的含量逐渐减少,{212}<141>织构组分的含量先增加后减少,{111}<112>织构组分的含量逐渐增加,织构组分以{110}<001>→{212}<141>→{111}<112>顺序演变。冷轧后样品中出现了孪晶,其晶体取向为{001}<110>,冷轧过程中孪晶取向没有发生变化。     

Texture and Formability of One-Step and Two-Step Cold-Rolled and Annealed Interstitial Free High-Strength Steel Sheets

In the current experimental investigation, a comparative study has been carried out to understand the development of texture under different conditions, viz. controlled hot-rolled, one-step cold-rolled (CR) and annealed, and two-step cold-rolled and annealed conditions. Mechanical properties were determined and experimental formability limit diagrams (FLDs) were plotted after both one-step and two-step cold-rolled and annealed conditions. From the tabulated data, it was found that hot band texture of 85 to 90 pct deformation was strong and the main orientations were ( 112 )[ 1[`1]0 ] \left( {112} \right)\left[ {1\bar{1}0} \right] and ( 332 )[ [`1][`1]3 ]. \left( {332} \right)\left[ {\bar{1}\bar{1}3} \right]. One-step cold rolling developed the strong and uniform α-fiber and γ-fiber at 80 pct cold reduction. The strong and uniform new γ-fiber was obtained at the one-step 80 pct CR annealed condition. In addition, the highest drawability was found at the one-step 80 pct CR annealed condition. In two-step cold rolling, orientation ( 223 )[ 1[`1]0 ] \left( {223} \right)\left[ {1\bar{1}0} \right] was the main texture component along with extremely strong γ-fiber. Moreover, batch annealing of two-step cold-rolled steel sheets developed exceptionally strong and uniform γ-fiber, and all mechanical properties were enhanced significantly except yield strength. From FLDs, it is observed that the formability properties of interstitial free (IF) high-strength (HS) steel sheets were excellent at both one-step and two-step cold-rolled and annealed conditions. However, the two-step cold-rolling and annealing process was found to be superior to the one-step process. The data of this investigation may be used at the industrial level to design the entire processing of IF-HS steel sheets.     

TSCR试制低碳低硅无取向电工钢织构的演变

 研究了模拟TSCR流程生产的低碳低硅无取向电工钢在热轧-冷轧-退火过程中织构的演变。对热轧板采用EBSD技术进行织构的测定,而对冷轧板和退火板采用X射线衍射技术进行了织构的测定。结果表明：热轧板沿板厚方向织构变化比较明显,在1/10处主要织构为α纤维织构和γ纤维织构;在1/4厚度处出现了较强的γ纤维织构;在1/2厚度处主要为较强的{001}〈110〉织构,其他织构分布漫散。冷轧板表面和中心处主要织构均为α纤维织构和γ纤维织构,但是在中心处两织构强度都显著减弱。退火板表面和中心处α纤维织构基本消失,γ纤维织构织构进一步加强,出现了{110}〈001〉高斯织构和{001}〈010〉立方织构。