Ti超低碳烘烤硬化钢铁素体区轧制试验研究

实验室进行了Ti处理超低碳烘烤硬化钢的常规奥氏体区热轧和铁素体区润滑轧制以及冷轧、连续退火试验,结果表明与常规奥氏体区轧制相比,铁素体区润滑轧制能够提升超低碳烘烤硬化钢板的深冲性能,在伸长率相当的情况下退火后钢板的屈服强度和烘烤硬化BH值均略有所下降.EBSD微观取向分析表明,铁素体区润滑轧制退火钢板中的<111>//ND纤维织构稍强,两种情况下退火板中晶粒间取向都是以大角度晶界为主.     

析出相对深冲DP钢组织性能及织构的影响

为了研究析出相对深冲DP钢织构的影响机制,采用Thermo-calc热力学软件计算DP钢的平衡析出相,并利用SEM、TEM与XRD等手段分析了两种不同成分的DP钢组织性能与织构演变.研究表明:试验钢的主要析出相为MC_SHP、M₇C₃、MnS和AlN;与低Mo钢相比,高Mo钢的奥氏体区被缩小,且MoC的析出温度更高,铁素体晶内与沿晶界形成了大量的纳米级MoC析出;860 ℃退火后,高Mo钢中形成了约3%的均匀弥散分布的马氏体,抗拉强度达到445 MPa,r值为1.5,而低Mo钢发生了贝氏体相变,各项力学性能明显降低;两种试验钢的热轧板织构较弱,冷轧后{223}<110>取向密度稳定增加,退火后均形成了强烈的γ纤维织构,而低Mo钢中{001}<110>织构是导致其r值偏低的主要原因.     

退火工艺参数及母材性能对取向硅钢超薄带磁性能的影响EI北大核心CSCD

采用EBSD技术对不同退火工艺处理后的冷轧取向硅钢超薄带样品进行研究,分析退火样品的显微组织、织构与磁性能的关系,讨论母材性能对超薄带性能的影响。结果表明:冷轧超薄带的退火组织均匀、Goss取向度高以及母材磁性能优良均可有效提升磁性能;退火升温速率主要影响晶粒尺寸、Goss取向度及磁性能;再结晶的平均晶粒尺寸改变,会影响最终超薄带的磁感应强度及铁损;在900℃退火5 min以上会明显发生再结晶,10~30 min内退火的超薄带磁性能变化较小,退火15 min获得最佳磁性能。此外,在1000℃及1100℃下退火的时间均不宜超过10 min,否则会恶化磁性能。     

深冲IF钢再结晶{111}纤维织构形成机制探讨

为了探讨深冲IF钢再结晶织构与退火温度之间的关系及{111}再结晶织构形成机制,采用X射线衍射三维取向(ODF)和背散射电子衍射(EBSD)分析技术并结合金相组织观察,利用Gibbs-Thom son方程对冷轧IF钢在不同退火温度下的再结晶织构演变规律及形成机制进行研究.实验结果表明:随着退火温度的增加,再结晶量逐渐增多,γ纤维织构强度亦相应增强,同时,α纤维织构强度则逐渐降低;冷轧IF钢再结晶初期的织构转变主要发生在γ纤维织构之间.研究表明,再结晶核心的形成主要以"显微择优形核"为主,晶核的长大则主要以择优生长为主,而Σ重位点阵晶界在再结晶γ纤维织构形成过程中起着重要作用.     

超快速退火对Nb+Ti-IF钢组织和织构的影响

研究了超快速退火对一种冷轧变形量为94.2%的Nb+Ti-IF钢的微观组织和织构的影响。结果表明:超快速退火(升温速度为300℃/s)提高了钢的再结晶完成温度,整个再结晶退火可在短至0.41 s内完成。与普通退火(升温速度为20℃/s)后钢的再结晶组织相比,超快速退火处理后晶粒平均尺寸由12.98μm细化到10.12μm,晶粒长大速度由～3μm/s提高到～23μm/s,且再结晶晶粒内存在大量缠结位错。在极短时间内,超快速退火再结晶织构仍以均匀、锋锐的{111}//ND有利深冲性能的γ织构为主,且避免了其它α织构的生成,有利于使退火板具有良好的成形性能。     

0.20mm CGO硅钢高温退火Goss晶粒起源及异常长大行为研究

利用X射线衍射织构分析技术和电子背散射衍射微织构分析技术,对0.20mm CGO硅钢薄板在高温退火缓慢升温过程中表层和次表层的织构演变规律进行了研究。结果表明:0.20mm CGO硅钢在高温退火过程中经历了低温回复、初次再结晶、初次再结晶晶粒长大和二次再结晶形成最终锋锐Goss织构的演变过程。Goss取向晶粒最初起源于变形回复基体中残存于{111}〈112〉形变带上少量的Goss晶粒亚结构,600℃保温2h后,Goss取向晶粒率先从变形基体中转变形核,在随后的升温过程中逐渐发生再结晶,Goss取向晶粒在此过程中并不具有尺寸优势,700℃时初次再结晶完成,基体中以γ纤维织构和{112}〈110〉织构为主;随着退火温度的升高,Goss晶粒的含量和平均晶粒尺寸逐渐增加,在900~1000℃之间,Goss取向晶粒迅速"吞噬"其他取向晶粒形成锋锐的Goss织构,1000℃时已经发生了二次再结晶。     

罩式退火无间隙原子钢的最优冷轧压下率的确定

以工业生产的含钛、铌和含钛的两种无间隙原子(IF)钢热轧钢板为试验材料,在实验室研究了冷轧压下率对两种IF钢的显微组织、力学性能和再结晶织构的影响。结果表明:在试验条件下,两种试验钢经不同冷轧压下率冷轧和720℃×5 h罩式退火后,再结晶完成,随着冷轧压下率的增加,晶粒变得细小均匀,退火后得到的织构也增强,并且织构类型有转向{111}织构的趋势;塑性应变比r90在压下率为70%时达到最大值,随着冷轧压下率的进一步增大,r90值减小;应变硬化指数n90值逐渐降低。最后提出工业生产中冷轧压下率最佳范围为70%~80%,可获得良好的深冲性能。     

800MPa冷轧热镀锌双相钢组织性能及其织构演变

对800MPa级热镀锌双相钢热轧、冷轧及退火后的显微组织进行了观察,分析比较了热轧和退火后的力学性能,并考察了其织构演变过程.结果表明:实验用钢经820℃保温140s热镀锌退火后,可获得抗拉强度819MPa,伸长率为17%的铁素体+马氏体双相钢,铁素体晶粒尺寸在1.5~4μm之间,马氏体体积分数为34%左右;热轧织构密度较弱,但已呈现出γ织构的雏形;冷轧后α织构和γ织构密度显著增长;热镀锌退火后α织构变化不大,不利织构{001}〈110〉织构密度有较大程度地攀升,γ织构取向密度值波动很大,最大织构组分为{112}〈110〉织构;快冷过程中形成的马氏体阻碍了有利织构{111}的发展,使得不利织构{001}〈110〉得到一定程度的发展.     

二次冷轧压下率对DCR带钢力学性能与织构的影响

借助于三维取向分布函数(ODF)及EBSD方法,研究了DCR带钢在不同二次冷轧压下率下的力学性能与微观织构变化。实验结果表明:采用二次冷轧加工的DCR带钢在二次冷轧压下率为20.9%时具有相对较好的延展性能;且当压下率约为20.9%时,基本织构组分达到稳定,此时继续增大压下率的作用主要是细化晶粒;压下率超过24.7%时,增大压下率不利于获得弱的α取向纤维织构(〈110〉//RD)和较强的γ取向纤维织构(〈111〉//ND),这将影响材料的深冲性能。     

低碳Cr-Mo系深冲双相钢组织与织构演变

通过组织观察以及TEM与XRD技术研究了低碳Cr-Mo系深冲双相钢组织与织构演变规律。结果表明:奥氏体未再结晶区终轧有利于形成{112}〈111〉织构,冷轧过程中{001}〈110〉,{112}〈110〉与{223}〈110〉织构稳定增加,退火过程中形成有利于深冲性能的〈111〉//ND以及{554}〈225〉与{332}〈113〉织构;820℃与860℃临界区退火后γ纤维织构密度差异较小,但是高温退火增大{111}〈110〉与{111}〈112〉织构的取向密度差值,归因于贝氏体中的固溶碳以及贝氏体相变时的变体选择;高温卷取能诱发热轧板中Mo基碳化物粒子析出,并在退火保温过程中回溶,既能发展再结晶织构,又能促进第二相形成。     

Significant effect of as-cast microstructure on texture evolution and magnetic properties of strip cast non-oriented silicon steel

In this study, two types of as-cast microstructure produced by strip casting were cold rolled and annealed to investigate the effect of initial microstructure on the textural evolution and magnetic properties of non-oriented silicon steel. The results indicated that the cold-rolled sheets of coarse-grained strip with pronounced {100} components exhibited stronger λ fiber (〈100〉//ND) and weaker γ fiber (〈111〉//ND) texture as composed to the fine-grained strip with strong Goss ({110}〈001〉) texture. After annealing, the former was dominated by η fiber (〈001〉//RD) texture with a peak at {110}〈001〉 orientation, while the latter consisted of strong {111}〈112〉 and relatively weak {110}〈001〉 texture. In addition, a number of precipitates of size ～30–150?nm restricted the grain growth during annealing, resulting in recrystallization of grain size of ～46?μm in the coarse-grained specimen and ～41?μm in the fine-grained specimen. Ultimately, higher magnetic induction (～1.72?T) and lower core loss (～4.04?W/kg) were obtained in the final annealed sheets of coarse-grained strip with strong {100} texture.     

Effects of Primary Annealing Condition on Recrystallization Texture in a Grain Oriented Silicon Steel

The recrystallization texture in grain oriented silicon steel sheets, which were annealed at different primary annealingtemperatures with and without an electric field, was investigated. An automated electron backscattered diffraction(EBSD) technique was used to analyze the recrystallization texture. It was found that recovery and application ofelectric field in primary annealing lead to an increase of {001} component and a decrease of {111} component afterannealing at 900℃. The development of recrystallization texture can be explained in terms of the effects of electricfield and primary annealing temperature on recovery.     

残余碳对取向硅钢初次和二次再结晶的影响

研究了脱碳退火样品中的残余碳对取向硅钢初次和二次再结晶的组织和磁性能的影响。结果表明：随着脱碳退火样品中残余碳含量的提高,初次再结晶的平均晶粒尺寸减小,表层和中心层的晶粒尺寸差增大;初次再结晶的强{111}<110>或{111}<112>织构向强{112}<110>织构转变,部分1/4层的Goss晶粒或{111}<112>晶粒转变为其他取向的晶粒;残余碳含量超过0.0200%后,高温退火样品二次再结晶不完善,磁性能较差。相变是导致上述现象的主要原因。     

退火张力对无取向硅钢再结晶织构和磁性能的影响

采用取向分布函数(ODF)分析了无取向电工钢冷轧板施加不同张力时再结晶退火后组织织构的变化.结果表明,随着退火张力的增加,再结晶晶粒尺寸逐渐增大,当退火张力为4 MPa时,晶粒平均直径达最大值75 μm,且尺寸均匀,Cross织构和立方织构组分也增强,其铁损P1.5/50降低到4.34 W· kg-1,同时磁感Bs.升至1.684 T;当张力增加到6 MPa时,晶粒直径减小至40 μm,{110}<001>和{001}<100>织构组分减弱,γ线织构组分明显增强,磁性能恶化.     

Texture evolution during inclined cold rolling of used non-oriented silicon steel

With the objective of optimizing the texture components and exploring a method to improve the magnetic properties of used silicon steel, the methods of one inclined rolling and two inclined rolling were applied. The result shows: the new Goss grains were nucleated except at {111} deformed grains, and also formed at the grain boundary between two deformed grains with {113} orientation, and at grains boundaries between {113} and {100} deformed grain. The grain size after one inclined rolling (57 %) was larger and more homogeneous than the grain size after the two inclined rolling. Although with different cold rolling methods (one and two inclined rolling), the resulted annealing textures all had similar features. The difference was the relative intensities between the main texture. A significant feature of one inclined rolling was the intensification of the η-fiber and the Goss texture component and the weakening of γ-fiber. At an inclination angle of 60°, a significantly strong Goss texture was produced, which was highest among all samples, and the maximum volume fraction of {110}+{100} texture can also be obtained. One inclined rolling can better improve the magnetic properties of used silicon steel (B₅₀), and the magnetic induction is between 1.712 T and 1.742 T. The highest magnetic induction of 1.742 T can be obtained by one inclined rolling (at an inclination angle of 60°).     

High magnetic field effect on texture and grain growth of GNO silicon steel

Magnetic annealing at 800 °C for 3, 15 and 30 minutes was conducted to evaluate the effect of a 17T magnetic field on the microstructure formation of cold rolled Fe‐0.75 %Si samples. According to texture measurements magnetic field did not seem to significantly affect the development of grains with Goss orientation, however it showed to affect the nucleation and growth process of {001}, {110} and {111} grains by increasing the volume fraction of the η fiber and by decreasing the fraction of the alfa and gamma fibers. ESEM/OIM and optical microscope results indicate that although magnetic field may retard nucleation it also promotes grain boundary displacement and for longer annealing times the retardation effect is compensated by the magnetic filed driving force.     

P、Ti对高强IF钢{=111}面织构的影响

借助电子背散射衍射（EBSD）技术测量和计算了高强IF钢退火试样的取向分布函数（ODF）、织构组分的含量和7取向线强度。研究了{111}（112）和{111}010）织构组分的变化,分析了P、Ti对{111}面织构的影响机理。P的存在阻碍了位错的运动和晶界的迁移,进而使再结晶晶粒取向趋于一致,形成较尖锐的{111}面织...     

Formation of {111} fibre texture in recrystallised aluminium sheet

Abstract

The deep drawability of commercial purity aluminium sheets is improved by introducing a (in fcc materials rather unusual) {111} fibre texture in the sheet surface layers. An additional step of warm rolling after the conventional hot and cold rolling leads to the formation of a pronounced shear texture in the sheet surface layers. During the final recrystallisation annealing, the desired {111} texture prevails at the expense of the other shear texture components. The present paper aims to clarify the mechanisms of the formation of {111}∥ND orientations during both warm rolling and recrystallisation. The effect of the {111} surface texture on the plastic anisotropy of the resulting sheets is discussed.     

IF钢铁素体区热轧和退火过程中织构的演变

研究了一种Ti—IF（Interstitial—free）钢在铁素体区热轧和退火过程中织构的变化．由于轧制过程摩擦的影响,热轧织构和退火织构在厚度方向上都有很大的差异．在钢板的表层,热轧织构的主要组分是{110}（001）,退火后表层的铁素体晶粒没有发生再结晶,该组分转变为（001）（110）;在试样的中心和1／4面,热轧织构组分主要是较弱的（111）／／ND（板法向）织构和部分（110）／／RD且在{001}（110）处最强;退火后中心面上的晶粒发生了完全再结晶,{001}组分转变为（111）／／ND组分使（111）／／ND织构成为唯一织构组分且在{111}（112）处最强．