CSP工艺冷轧薄板盐浴退火再结晶实验

 研究了以CSP工艺热轧板卷为原料的冷轧薄板在盐浴退火过程中的再结晶行为,通过显微组织、显微硬度及电子背散射衍射技术观察、分析揭示了再结晶的规律,结果表明,CSP工艺冷轧薄板经盐浴退火后的再结晶组织为等轴状晶粒;在相同温度下盐浴退火,冷轧压下率较大时,完成再结晶所需的保温时间较短,再结晶晶粒细小。     

不同退火工艺下TWIP钢微观组织及力学性能演变

摘要：以在650℃温轧的Fe-24Mn-2Al-1Si-0.05C TWIP钢为研究对象,通过金相显微镜(OM)、扫描电镜（SEM）、透射电镜（TEM）、室温拉伸等实验手段,研究温轧TWIP钢在回复退火、部分再结晶退火、高温短时退火以及高温退火等不同退火工艺下其微观组织及力学性能的演变。结果表明,随着退火工艺的改变,实验钢的微观组织由回复退火时包含高密度位错、形变孪晶等的变形晶粒逐渐向高温退火时的无畸变再结晶晶粒转变;而部分再结晶退火时,实验钢的微观组织由未再结晶区的变形晶粒和细小的再结晶晶粒混合组成。随退火工艺的改变,实验钢拉伸前、后的硬度变化趋势为先下降然后基本不变最后上升;实验钢的变形机制逐渐由位错滑移为主向孪生滑移为主转变。     

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.      

H68合金退火料温对其晶粒度的影响(续)

2试验方案和退火工艺 2．1试验方案 根据前节分析,H68合金属单相α高锌合金,第一再结晶温度低,第二晶粒易长大。结晶理论指出,原始晶粒粗大,加工退火后再结晶晶粒亦大,H68合金在成品冷轧前需经两次中间退火（6．5mm热轧卷坯退火,2．3mm冷轧卷坯退火）,     

SPCC薄板冷轧及连续退火工艺研究

对SPCC薄板进行了冷轧及连续退火模拟试验。研究了冷轧及连续退火工艺对SPCC薄板再结晶组织的影响效果,以及再结晶晶粒尺寸对SPCC薄板力学性能的影响规律。研究发现,经工艺参数优化,可显著降低退火薄板的再结晶晶粒尺寸,同时提高薄板的屈强比性能指标。在晶粒尺寸最为细小的5.23μm SPCC薄板中得到市场上同类产品中最高的屈强比性能。     

冷轧薄钢板退火组织的计算机模拟

利用Monte Carlo方法及模型进行了冷轧薄钢板静态再结晶退火组织的模拟。通过采用Visual C 在Windows 96平台上的模拟研究，观察了退火过程中钢板组织的连续变化，包括退火时晶界迁移和晶粒相互吞并的过程。模拟了冷轧钢板退火过程晶粒尺寸，再结晶百分比的变化规律 以及冷轧压下率对再结晶的影响，将模拟结果与试验结果对比，二者十分吻合。     

退火温度对钽丝再结晶织构的影响

采用极图与取向分布函数（ODF），并通过显微组织观察及显微硬度测试，研究分析了90％冷拉减面率的变形钽丝在1100℃、1250℃、1360℃、1500℃下退火过程中的再结晶行为，提出了拉拔钽丝的再结晶模型。研究发现：在低温火后钽丝发生了强烈的回复；在1360℃退火后再结晶基本完成，出现了均匀的等轴状晶粒，再结晶织构{110}＜001＞与变组织构{112}＜110＞之间存在27℃＜110＞的关系；在1500℃退火后钽丝中发生了二次再结晶，品粒变得粗大，并出现了一种与原再结晶织构{110}＜001＞呈27℃＜110＞关系的再结晶织构组分{441}＜110＞。钽丝的再结晶行为符合选择生长理论。     

冷轧薄钢板退火过程组织演变的Monte Carlo模拟

利用 Monte Carlo方法及模型进行了冷轧薄钢板静态再结晶退火组织的模拟 ,实现了退火组织的连续动态变化过程 ,可以观察晶界的迁移及晶粒在退火过程中相互吞并的机理和过程。还模拟了冷轧钢板退火过程中晶粒尺寸及再结晶分数的变化规律及冷轧压下率对再结晶的影响。将模拟结果与实验结果进行对比发现 ,两者基本吻合。     

Ti-IF钢回火过程的再结晶规律

本文对比研究了Ti-IF钢罩式退火工艺下的再结晶规律及连续退火工艺下再结晶规律。分别采用随炉升温到不同温度测定再结晶规律,和采用到温入炉保温100s出炉测定再结晶规律。模拟罩式退火采用两阶段随炉升温,所测试样的名义再结晶温度为620,实际的再结晶温度为660℃,实验钢在随炉升温至660℃下完成再结晶过程历时68min;700℃、720℃再结晶的新晶粒开始长大;800℃时,再结晶的晶粒等轴化。模拟连退采用快速升温到不同温度,试样到温入炉保温100s出炉空冷,660℃再结晶开始形核,700℃形核的数量开始增加,720气：形核数量急剧增加,800 ～840℃再结晶晶粒长大,晶粒均匀化,900℃发生二次再结晶,晶粒反常长大。     

取向硅钢板脱碳退火控制方法

取向硅钢板脱碳退火控制方法［日］石飞宏威等１现在技术及存在的问题取向硅钢经冷轧至最终板厚，在湿Ｈ２中７００９００℃范围进行连续退火，以形成适宜的１次再结晶；脱Ｃ，使Ｃ由０．０１％０．１％（质量分数）脱到０．００３％以下；以及通过氧化反应在钢板表层生成...     

IF钢罩式退火过程中再结晶组织与织构的演变

研究了IF钢(/%:0.005C、0.02Si、0.16Mn、0.011P、0.004S、0.042Als、0.061Ti、0.003 1 N)0.8 mm冷轧板在500～800℃退火时的再结晶组织及织构,采用X射线衍射技术结合微观组织观察分析了IF钢罩式退火过程中{111}再结晶织构形成机制和显微组织演变规律。结果表明,随退火温度的升高,再结晶数量逐渐增多,640℃为实验钢实际再结晶温度,同时{111}再结晶织构强度亦逐渐增大,{111}取向的晶粒主要在再结晶过程中形成,并在{111}取向晶粒长大过程中,γ纤维织构之间也发生相互转化,主要由{111}〈112〉织构转变为{111}〈110〉织构。     

退火参数对ZE42镁合金热挤压板显微组织结构的影响

采用光学显微镜和TEM观察等方法,分析了ZE42镁合金热挤压板材在不同退火温度和时间条件下的显微组织结构。结果表明:该合金板材经过退火热处理后均发生明显的再结晶组织转变,晶粒尺寸在10～60μm之间,合金基体中存在大量含有稀土元素的第二相颗粒,这些第二相在热变形过程中破碎成细小的颗粒,促进了再结晶晶粒的形核。当退火温度一定时,随着保温时间的延长,该合金板材的平均晶粒尺寸首先增加,随后少量减小,最后又随退火时间的增加而增加;当保温时间一定时,随着退火温度的增加,晶粒平均尺寸持续增加,并且温度越高,增长速率越大。同时,通过晶粒长大动力学分析和计算建立了该合金再结晶晶粒长大的动力学模型,通过计算可知:该合金的再结晶晶界迁移激活能为15.32 kJ·mol-1。     

Evolution of recrystallization and recrystallization texture in continuous-cast AA 3015 aluminum alloy

The evolution of recrystallization and recrystallization texture during annealing after cold rolling of a continuous-cast (CC) AA 3015 aluminum alloy with and without pretreatment was investigated in detail. It was found that the preheat treatment prior to cold rolling significantly affected the recrystallization kinetics, the shape and size of recrystallized grains, and the resulting texture of the CC AA 3015 aluminum alloy. In the case of the alloy without pretreatment, annealing at low temperatures resulted in coarse elongated recrystallized grains and a very strong P texture. As the annealing temperature increased, the size of the recrystallized grains dramatically decreased, the recrystallized grains became equiaxed, and the strength of the P texture decreased. The transition behavior could be attributed to the effect of Zener-particle pinning caused by concurrent precipitation. In contrast, the recrystallization texture of the CC AA 3015 aluminum alloy with pretreatment was characterized by a major cube component and a minor R component, and the annealing temperature did not affect the recrystallization texture. Moreover, concurrent precipitation retarded markedly the recrystallization of the CC AA 3015 aluminum alloy, decreased the Johnson-Mehl-Avrami-Kolmogorov (JMAK) exponent from 2.0 to 0.5, and increased the activation energy for recrystallization from 225 to 539 kJ/mol.     

含钛超低碳搪瓷钢板的退火工艺

 研究了两种不同退火工艺——罩式退火和连续退火工艺对含钛超低碳搪瓷钢板成型性能和贮氢性能的影响。试验结果表明,材料经连续退火后其成型性能略优于罩式退火,而其贮氢性能是经罩式退火后的明显好于连续退火。因此综合考虑,采用罩式退火工艺可实现成型性能和贮氢性能的良好匹配。     

冷轧薄钢板退火再结晶的计算机模拟

采用Monte Carlo方法和简化的物理模型所编制的程序较好地模拟了冷轧钢板退火组织的演变过程及变化规律，模拟程序所演示的退火过程晶粒尺寸和再结晶百分比变化与实验所得到的结果一致。     

Development of Bimodal Ferrite-Grain Structures in Low-Carbon Steel Using Rapid Intercritical Annealing

Mixed ferrite grain structures, which have fine- and coarse-grain regions and showing “bimodal” grain size distributions, have been produced by rapid intercritical annealing of warm-rolled (or cold-rolled) samples. Microstructural changes have been analyzed using dilatometric studies, size prediction of transformed and recrystallized grains, and microtexture measurements. Fine austenite grains (<5 μm) developed during rapid annealing and transformed into fine-ferrite grains (2 to 4 μm) after cooling. Coarse-ferrite grains (28 to 42 μm) resulted from the recrystallization and growth of deformed ferrite. The effect of heating rate on microstructural morphologies during intercritical annealing has also been studied. A slow rate of heating (30 K/s) developed a uniform distribution of fine-ferrite grains and austenitic islands, while rapid heating (300 K/s) generated coarse blocks of austenite, elongated along the prior-pearlitic regions, in the ferrite matrix. As expected, bimodal ferrite grain structures or fine-scale dual-phase structures showed superior combination of tensile strength and ductility, compared to the ultrafine-grained steels.     

Evolution of Microstructure and Texture during Annealing of Aluminum AA1050 Cold Rolled to High and Ultrahigh Strains

The microstructure and texture of commercial purity aluminum (AA1050) have been investigated after cold rolling to von Mises strains of 3.6 to 6.4 followed by recovery and recrystallization during annealing. The evolution of structural parameters of the deformed microstructure, such as boundary spacing and fraction of high-angle boundaries (HABs), did not reach saturation in the given strain range. Recovery was accompanied by structural coarsening and by a decrease in the fraction of HABs. The coarsening rate increased with increasing strain prior to annealing. Recrystallization nuclei were found to form both in deformation zones around coarse particles and in recovered lamellar structures. The process of recrystallization in the present material can thus be characterized as discontinuous recrystallization. In recrystallized conditions, the average grain size was related to the grain orientation: the mean size of grains having orientations of the rolling texture was smaller than the size of grains with other orientations. The orientation dependence of the recrystallized grain size was more pronounced in the samples rolled to ultrahigh strains.     

退火温度对Nb+Ti-IF钢性能与织构的影响

采用显微硬度仪、金相显微镜和X射线衍射仪研究了退火温度对冷轧Nb+Ti-IF钢的硬度性能、金相组  织和织构的影响。试验结果表明:随着退火温度的升高,退火试样的维氏硬度降低,晶粒由轧制的扁长状长成等轴  或近似等轴状态,γ-纤维织构不断吞并α-纤维织构而增强,对应的α-纤维织构则不断减弱。从工业生产和节约能  源的角度考虑,Nb+Ti-IF钢的再结晶退火温度应控制在800℃左右。     

高性能取向硅钢的工业化生产研究

采用光学显微镜、X射线衍射仪等分析了宁波钢铁有限公司生产的取向硅钢不同工序下的组织及织构演变规律.结果 表明:铸坯经过热轧后,沿着厚度方向组织不均匀;一次冷轧并经脱碳退火后,组织由条状纤维状变成等轴状的初次再结晶晶粒,初次再结晶平均晶粒尺寸为18.17 μm,织构主要以α织构和γ织构为主;在二次冷轧后,晶粒再次被压缩,转变为纤维状,织构主要为γ织构;经过高温退火后,发生二次再结晶,晶粒异常长大,晶粒尺寸达到厘米级,织构成分为单一且锋锐的Goss织构.     

Effect of Annealing Temperature on Recrystallization Behavior of Cold Rolled Ti-Microalloyed Steel

In order to develop cold rolled Ti-microalloyed steel strips, the effects of annealing temperature on recrystallization behavior of experimental steel were researched by optical microscopy (OM), transmission electron microscopy (TEM) and Vickers hardness test. The annealing treatment could be divided into three distinct stages: recovery, recrystallization and grain growth. Recrystallization took place from 933 to 1033 K, during which a large number of recrystallized grains appear and hardness drops sharply. The morphology and size of TiN particles nearly remained unchanged at different stages of processing. With increasing annealing temperature, nanometer precipitates coarsened and the dislocation density was significantly reduced. In comparison with annealing time, annealing temperature was more crucial for recrystallization of cold rolled Ti-microalloyed steel. It could be concluded that the pinning force of nanometer particles on dislocations increased the recrystallization temperature. At higher annealing temperature, recrystallization took place because of precipitates coarsening caused by Ostwald ripening.