“ASP+罩式退火工艺”生产Ti-IF钢的织构演变

对济钢"ASP+罩式退火工艺"下生产的Ti-IF钢的热轧、冷轧及退火试样的织构演变进行分析。借助XRD测定并计算了热轧、退火及冷轧试样的取向分布函数和相关织构组分的体积分数。结果发现,济钢Ti-IF钢热轧板形成了较强的{111}面织构;在冷轧和退火后γ纤维织构显著增强;冷轧织构在罩式退火后,{111}<110>织构强度减弱,{111}<112>织构增强,{111}/{100}比值增加。     

ASP工艺下Ti-IF钢微观织构演变规律研究

利用X射线衍射三维取向分布函数(ODF),对济钢"ASP+罩式退火工艺"下生产的Ti-IF钢的热轧、冷轧及退火、平整试样的织构演变规律进行研究。结果表明:济钢Ti-IF钢热轧板形成了较强的{111}面织构,在冷轧和退火后γ纤维织构强度显著增强;经罩式退火后,{111}110织构强度减弱,{111}112织构强度增强,V({111})/V({100})增大;经平整工序后高斯织构强度略有增强;随着碳含量的增加,Ti-IF钢在各生产工序的有利织构{111}减少,有害织构{100}增加,成形性能变差。     

JSP-双机可逆冷轧条件下IF钢织构研究

针对济钢现场工艺条件下生产的Ti-IF钢,利用X’Pert ProxX射线衍射宏观织构分析方法,研究了中薄板坯热连轧轧制及随后的冷轧、退火工艺过程中织构的变化规律。IF钢冷硬板主要织构类型为{111}〈110〉、{111}〈112〉和{001}〈110〉,其中{111}〈110〉织构强度达到12;再结晶退火后的IF钢退火板,主要织构类型为{111}〈110〉和{111}〈112〉,{111}〈110〉织构强度提高到15.37。济钢生产的Ti-IF钢获得了对板材成形最有利的{111}//ND织构。     

冷轧压下率对连续退火Ti-IF钢组织和织构的影响

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射线织构测试等分析手段,研究了冷轧压下率对组织和织构的影响规律。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,而且主要形成了{223}110和{114}110织构,γ线上的{111}110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;试验钢退火后仍具有较强的{223}110和{114}110织构,且随着冷轧压下率的提高,{111}织构有增强的趋势。要获得强的{111}织构,冷轧压下率需在80%以上。     

Nb＋Ti—IF钢二次冷轧性能和织构特征

主要通过对铁素体区热轧板坯进行不同压下率的一次冷轧和二次冷轧试验,采用ODF对比一次冷轧观察了（100）,{111}和Goss面织构在二次冷轧过程中的演变。二次冷轧的织构特征是获得较高占有率的{111}织构和较低占气有率的{100}织构,二次冷轧在一次．冷轧的基础上加强了{111}〈112〉组分。通过TEM和力学性能测试分析了二次冷轧中压下率分配方式对织构演变和材料最终退火组织性能的影响,为IF钢二次冷轧工艺工业化生产提供理论依据。     

冷轧压下率对IF钢织构的影响

采用CSP工艺生产厚度为3.5 mm的IF热轧钢板,分析了冷轧压下率对冷轧织构、退火织构、各组分含量、{111}/{100}比值的影响。结果表明,采用71.4%的冷轧压下率生产的IF钢{111}织构占比最大,最有利于冲压性能的提高。     

冷轧Ti-IF超深冲钢罩式退火机理及织构变化规律的研究

在480~750℃条件下,模拟罩式退火,利用光学显微镜、X射线衍射和金相显微硬度计研究了冷轧Ti-IF超深冲钢晶粒结构的变化,通过取向密度函数分析了再结晶过程织构演变规律。研究表明:冷轧Ti-IF超深冲钢的再结晶温度约为630℃,再结晶过程能够在660℃条件下2 h之内完成;冷轧后该钢主要有4种织构,分别是{001}〈110〉、{111}〈110〉、{111}〈112〉和{112}〈110〉;在退火再结晶过程中,{111}逐渐转变为γ-{111},当退火温度升至720℃时,{001}〈110〉和{112}〈110〉转变为纤维织构γ-{111},最终{111}〈110〉和{111}〈112〉成为主要织构类型。     

冷轧压下率对铁素体区热轧Ti-IF钢冷轧板深冲性能的影响

研究了于铁素体区润滑热轧的Ti-IF钢在随后的冷轧及退火工艺中深冲性能的变化.结果表明,在冷轧压下率为75 %时IF钢所获得的r值最高.织构分析表明,于铁素体区润滑热轧的IF钢具有较强的{111}∥ND再结晶织构组分;冷轧时采用75 %的压下率和随后的退火工艺可获得最强的{111}∥ND再结晶织构;冷轧压下率进一步增加时,{111}∥ND再结晶织构将会削弱.这种织构变化与冷轧时ND纤维晶粒内部的剪切带变化有关.     

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.     

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.     

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。     

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.     

Texture,Grain Boundary Characterization and Segregation of Phosphorus in an Annealed Interstitial Free Steel

The {111} fiND plane texture, grain boundary characterization and grain boundary segregation of phos- phorus are investigated for the phosphorus added high strength interstitial free （IF） steel annealed at 810℃ for 60 s to 180 s. The results show that the maximum volume fraction of {111} fiND plane texture is about 85% and the grain boundary Segregation peak of phosphorus is about 14 at. % for the steel annealed at 810℃ for 120 s. The ∑3 and other low-∑CSL （coincident site lattice） boundaries are lowest for the steel annealed for 120 s. Segregation of phosphorus is also found at low angle grain boundaries.     

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。     

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.     

Texture of Hot Rolled Strip for Fe-3Si Steel Produced by Thin Slab Casting and Rolling

 Fe-3%Si steel strip was experimental produced by thin slab casting and rolling (TSCR) process in the laboratory. The microstructure and texture of hot rolled strip by different total reduction and rolling schedule was observed through EBSD technique and X-ray diffraction method. The changeable rule of texture density on the α、ε and γ, and fibers was analyzed. When the total reduction was increased from 82.9% to 97.1%,the gradient of microstructure and texture for A steel surface layer and center layer was found, {001}&;#8249;110&;#8250; texture had higher intensity, and {001}&;#8249;110&;#8250; texture was changed to     

Influence of hot-rolling conditions on texture development in deep-drawing steels

As the textures of deep-drawing sheet steels are important for certain material properties the purpose of this paper was to take a closer look at the hot-rolling, cold-rolling and annealing textures of different deep-drawing steel grades. Several Al-killed mild steels and vacuum-degassed Ti-IF steels have been hot rolled in the mill varying the finishing temperature (FT). After coiling, cold rolling and short-time annealing the textures at different thickness levels have been measured by means of (110)-pole figures and orientation distribution functions (ODFs). For both steel groups the textures at the surface of the hot strip exhibit a more or less pronounced shear type character. Towards the mid-thickness level (with lower FT more clearly) typical (cold-) rolling textures exist characterized by a strong {001}<110> orientation and in the Ti-IF steels additionally by a significant {112}<110> orientation density. In the case of high FT cold rolling and annealing lead to favourable {111}-textures where deep-drawing application is concerned. For the Al-killed steels lowering FT results in diffuse recrystallization textures whereas in the Ti-IF steels a sharp texture with near {223}<582> orientations can be observed which have not been known for these steels before. The results prove that the hot strip textures can be of great importance for the resulting annealing textures and the according material properties.