冷轧压下率对含Nb细晶高强IF钢织构形成机制的影响

以含Nb细晶高强IF钢热轧板为研究对象,研究了冷轧压下率对实验钢冷轧织构以及再结晶织构形成影响。结果表明,退火后铁素体晶粒细化,强度提高。实验钢经冷轧后主要的织构为{112}110、{111}112、{111}110、{001}110,并且随冷轧压下率增加,织构组分无变化,各组分强度整体增加。再经退火后,在α线上织构减弱,甚至一些织构逐渐消失。提高冷轧压下率时,织构峰值逐渐由{001}110转为{111}110。对于γ取向线,峰值由{111}110取向变为{111}112取向,最终{111}112比{111}110取向强度大。实验钢再结晶机制由定向形核和选择生长共同作用的结果,并且随冷轧压下率增大,{111}面织构强度增大,所以r(塑性应变比)值增大,深冲性能提高。     

Al-1.8Cu-0.4Mg-0.4Mn合金一次冷轧织构与二次冷轧织构的研究

将Al-1.8Cu-0.4Mg-0.4Mn合金进行50%、60%、70%、80%不同压下量的一次冷轧,随后分别将一次冷轧压下率为50%和70%的样品进行等温中间退火并进行80%压下率的二次冷轧,对其织构演变过程进行研究。研究结果表明,当压下量大于60%时,一次冷轧的样品呈现“铜式”织构特征,即在α、β取向线上分布G、B、C及S组分,C、B和S组分强度随变形量的增加而增大,G组分则先增大后减小,在70%变形量时达最大。中间退火再结晶织构较弥散,但中间退火对二次冷轧织构有较大影响。初次冷轧变形量50%的样品形成弱的{001}<110>旋转立方织构,初次冷轧变形量70%的样品形成“铜式”织构。     

冷轧压下率对铁素体不锈钢深冲性能的影响

为了获得优良的深冲性能,通过变化冷轧压下率,研究了其对铁素体不锈钢显微组织,织构和深冲性能的演化规律.结果显示,随着冷轧压下率的增加,平均塑性应变比(r值)单调增加,这主要是因为退火织构{111}＜112＞强度的显著增加.另一方面,平面各向异性(△r值)随着压下率的增加先增加后减小,在冷轧压下率为80%时达到最小,冷轧压下率继续增加到90%时,退火织构的峰值逐渐偏离{111}织构,接近{223}＜582＞,△r值重新增大.     

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。     

轧制工艺对薄带铸轧无取向硅钢组织性能的影响

利用光学显微镜、XRD、EBSD等研究了轧制工艺对薄带铸轧无取向硅钢组织、织构和磁性能的影响。研究表明,随热轧压下率增大,冷轧组织变形储能及剪切带的比例逐渐降低,冷轧板中α织构减弱,γ织构增强。退火板晶粒尺寸随热轧压下率增大而增加。热轧压下率为17%及40%时,退火织构以强的Goss织构及相对弱的{100}织构为主,热轧压下率达到55%后,退火织构为强的{115}<110>和{114}<371>织构,Goss织构和{100}组分明显减弱。随热轧压下率增大,退火板磁感值先升高后降低,铁损值先减小后增加。热轧压下率为40%时,退火板综合磁性能最优。     

高强Nb-IF钢的深冲性能研究

以工业生产的高强Nb-IF钢为试验材料,在实验室研究了卷取温度和冷轧压下率对试验钢显微组织和力学性能的影响。结果表明:试验钢退火后均为完全再结晶组织;不同卷取温度下,随着冷轧压下率的增加,晶粒变得细小均匀;当卷取温度为650℃且冷轧压下率为75%时,以及卷取温度600℃和700℃且冷轧压下率65%时,试验钢的织构强度逐渐增大,并且峰值有向{111}织构靠拢的趋势,可以得到优良的深冲性能。     

390MPa级超低碳BH钢织构演变规律

采用ODF织构分析方法,对390 MPa级超低碳BH钢板热轧、冷轧、退火过程织构演变规律进行研究,并对不同冷轧压下量和不同退火工艺织构进行分析。结果表明:经冷轧变形后的钢板有较强的择优取向,具有典型的{112}<110>和{111}<110>织构,形变织构中的不利织构{001}<110>较强;冷轧压下率为80%时再结晶退火后钢板具有较强的γ织构,{111}<112>织构取向密度高达11.7;退火温度和保温时间对α织构影响不大,提高退火温度和延长保温时间使γ织构增强,r值增加。     

冷轧大压下量下新型无取向电工钢的退火组织演变

研究了冷轧大压下量,950 ℃退火时间对一种新型含铜无取向电工钢晶粒度和织构的影响.结果表明,大压下量冷轧,随压下量的增加,退火晶粒向γ线聚集,形成强{111}<112>织构.提高冷轧压下率,退火织构 {111}<100>,{110}<001>强度减弱,增加退火时间,退火织构{111}<110>,{100}<001>,{110}<001>强度变弱.采用87.5%冷轧压下率和950 ℃退火60 s,有利织构{100},{110}占有率最大.     

冷轧压下率对Nb-Ti复合IF钢力学性能及组织织构的影响

以工业生产的不同厚度规格Nb-Ti复合IF钢为试验材料,研究了冷轧压下率对IF钢力学性能及组织织构的影响。试验结果表明,随着冷轧压下率提高,IF钢退火板平均晶粒尺寸增大,强度降低,伸长率升高,塑性应变比r值增大,屈强比以及加工硬化值则变化不大;提高冷轧压下率,有利于促进γ织构,抑制α织构,优化成型性能,但是过高的冷轧压下率会恶化γ纤维织构的均匀性,增加Δγ值。     

冷轧压下率影响工业纯铝板退火织构变化的EBSD研究

采用电子背散射衍射分析方法,研究了34.7%和79.2%两种压下率对1060(L2)冷轧工业纯铝板退火期间织构演变过程的影响。结果表明,两种试验板冷轧织构均由β取向线的S、Brass和Copper织构组成,它们的体积分数随压下率降低而减小;两种试验板退火织构主要呈现为Cube织构组分增强和β取向线织构组分减弱的演变规律,且变化趋势随压下率增大而加强;在压下率为34.7%所对应的试验板中,Goss及其附近取向的晶粒主要发生了回复和被吞噬的现象,最终退火组织中取向差为60°的大角度晶粒数量较多。     

CSP生产SPHC板材的冷轧退火工艺研究

采用酒钢CSP工艺生产的SPHC热轧板,在实验室模拟了不同冷轧及退火工艺,并对冷轧钢板显微组织、力学性能和成形性进行了分析和研究。结果表明,当冷轧压下量为70%、退火温度为700℃时,冷轧板具有良好的织构和优异的冲压性能。     

Investigation on the Recrystallization Mechanism in Warm-Rolled Ti-IF Steel

The nuclei orientation, the nucleation site at the early stage of recrystallization, and the growth mechanism of the nuclei have been studied by EBSD analysis in Ti-IF steel during direct annealing after warm rolling. It is concluded that the formation of the recrystallization texture is dominated by the oriented nucleation mechanism. The recrystallized nuclei with γ-orientation emerged preferentially at the beginning of recrystallization and preferred to form in the deformed bands with γ-orientation and on the boundaries between γ- and α-orientations. The recrystallized grains first consumed their neighboring γ-oriented matrix; and then consumed the α-oriented deformed bands at the late stage of recrystallization, leading to strong γ-fiber.     

基于铁素体轧制工艺低碳铝镇静钢板r值降低原因分析

某钢厂试开发基于铁素体轧制工艺的SPCC板,经热轧-冷轧-罩式退火工序后对样品进行性能检测,发现与传统奥氏体轧制工艺相比,该工艺路径下的产品各项力学性能指标均有不同程度下降,且r值有明显降低。对两种工艺路径的热轧板和冷轧退火成品板进行了组织和织构的对比分析,且提出了改进措施。结果表明:铁素体轧制工艺中热轧精轧温度过高,形成两相区轧制,得到粗大F+纤维状F的不均匀室温组织,从而导致冷轧退火板中存在较高强度{001}<110>织构组分,是导致最终产品r值降低的主要原因。     

Texture Evolution,Formability and Ridging Resistance of a Sn-bearing Ferritic Stainless Steel Under Different Hot Band Annealing Temperatures

The microstructure, texture evolution and spatial orientation distribution during cold rolling and the subsequent annealing as well as formability and ridging of a Sn-bearing ferritic stainless steel under different hot band annealing temperatures were investigated. The four hot bands with annealing temperatures of 900, 950, 1000 and 1050 °C were all cold-rolled to 80% reductions and then were annealed at the same temperature of 900 °C. The results show that optimizing hot band annealing process is benefi cial to reduce the amount of {001} 110 grains and weaken the texture intensity, and thus, to reduce ridging and improve formability. In the present study, the fi nal sheets with hot band annealing temperature of 900 °C possess small and inhomogeneous grains with a large amount of {001} 110 orientations, which deteriorates the formability and increases the ridging. In comparison, the fi nal sheets with hot band annealing temperature of 950 °C are comprised of uniform and equiaxed 111//ND(ND: normal direction) recrystallized grains with a high texture intensity favorable for the improvement in r value and surface quality. However, when hot band annealing temperature further increases to 1000 and 1050 °C, it shows a sharp decrease in r value and a remarkable increase in ridging as a result of a reduction in γ-fi ber texture intensity and an increase in grain size in the fi nal sheets. Suitable controlling and optimizing hot band annealing process is essential to improve the formability and reduce the ridging.     

ORIENTATION VARIANT SELECTION AND ITS EFFECTING FACTORS IN TITANIUM SHEET

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超纯铁素体不锈钢织构演变与成形性能的研究

系统研究了超纯铁素体不锈钢(w(Cr)=17%)沿钢板厚度方向各层织构的演变规律和不同精轧温度对织构演变及成形性能的影响规律。采用X射线衍射仪分析了宏观织构演变。研究表明: 热轧及退火后, 钢板表层以剪切织构为主, 中心层由?和?纤维织构组成; 冷轧后, 各层均由较强的?纤维织构和较弱的?纤维织构组成; 冷轧退火后各层均形成?纤维再结晶织构。与高温精轧相比, 低温精轧有利于冷轧退火板?纤维再结晶织构的强化、偏离{111}<112>组分的程度降低, 从而显著改善冷轧退火板的成形性能。     

Effect of Laser Texturing on the Microstructure and Textures of 1050 Aluminum Alloy

To improve the surface morphology, formability, and deep drawing properties of 1050 aluminum alloy sheets, laser-textured rolls were used in cold rolling process. Effects of laser-textured rolls, comparing with conventional ones, on microstructure and texture of aluminum alloys after rolling and following recrystallization were studied. In aluminum sheets processed by laser-textured rolls and conventional rolls, microstructure and texture were similar after rolling, but significantly different after recrystallization. Laser texturing process results in finer and inhomogeneous recrystallized grains. The recrystallization texture of the specimen rolled with conventional roll has a major cube component and a minor R component. The intensity of cube component increases with increasing annealing temperature. However, recrystallization texture of the specimen rolled with laser-textured roller is much more random. The specimen shows that recrystallization texture has only a weak cube orientation but strong rotated-cube orientation as well as a much higher fraction of random orientation.     

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。     

Influence of Finish Rolling Temperature on Microstructure and Mechanical Properties of a 19Cr1.5Mo0.5W Ferritic Stainless Steel

A 444-type heat-resistant ferritic stainless steel containing 0.05 wt% Ce(rare earth element) and 2 wt%(Mo+W) was adopted as an experimental material to study the effect of finish rolling temperature on microstructure and texture evolution as well as on mechanical properties and formability.The rolling processes contain hot rolling at two different finish rolling temperatures(860℃ and 770℃) and annealing,cold rolling and subsequent annealing.It was found that the microstructures after hot rolling and annealing could be refined by lowering finish rolling temperature.The resultant microstructures after cold rolling and annealing were hereditarily refined.Lowering finish rolling temperature can weaken α-fiber texture in hotrolled or cold-rolled ferritic stainless steel strip,while γ-fiber texture in the final product was homogeneously strengthened.Additionally,enhanced mechanical property and formability in terms of strength and average plastic strain ratio could be obtained via decreasing finish rolling temperature.