大压下率冷轧无取向硅钢织构演变及性能

组织和织构是影响无取向硅钢性能的重要因素。为改善产品性能,研究了冷轧压下率(71.7%~87.0%)对高牌号无取向硅钢组织、织构、磁性能和力学性能的影响。结果表明,随冷轧压下率的增加,退火晶粒平均尺寸先减小后增大;高斯和立方织构强度减弱,γ纤维织构增强,α纤维织构转变为较强的α*({ h, 1, 1}〈1/h, 1, 2〉)织构,并随冷轧压下率的增加而增强,同时其峰值逐渐向{111}面移动;工频铁损P1.5/50、高频铁损P1.0/400和磁极化强度J5000同时降低,屈服强度变化不大,表面硬度逐渐增加。当冷轧压下率由84.7%增至87.0%、厚度减至0.30 mm时,高频铁损降幅是工频铁损的11倍,表面硬度增幅变大。以上研究成果对硅钢减薄后织构及组织的优化提供了很好的指导。     

常化温度对冷轧无取向硅钢薄带磁性能和织构的影响

研究了常化温度对冷轧无取向硅钢薄带磁性能和织构的影响.结果表明,冷轧无取向硅钢薄带生产过程中采用常化工艺能够降低高频铁损值,在900～950℃温度范围内常化能够降低成品硅钢中γ织构不利组分的强度,同时提高{100}面有利织构的强度.过高温度下常化会使成品晶粒尺寸偏大,导致涡流损耗增加,对冷轧无取向硅钢薄带的磁性能不利.     

成品厚度对无取向硅钢织构和磁性能的影响

研究了成品板厚度(0.35～0.65 mm)对0.003%C-2.40%Si-0.32%Al无取向硅钢织构演变、磁感和铁损的影响。结果表明,随着钢板厚度的减薄,成品中对磁性不利的织构组分增加,有利织构组分减少,磁感降低。在化学成分和晶粒尺寸一定的情况下,影响铁损的主要因素是钢板厚度,钢板厚度从0.65 mm减薄至0.35 mm时,铁损显著降低。     

不同厚度无取向电工钢在不同频率下的磁性能研究

通过测试马钢不同厚度的无取向电工钢在不同频率下的磁特性参数,比较分析了厚度和频率对无取向电工钢铁损和磁导率的影响。结果表明,钢板厚度减薄,涡流损耗急剧减小,进而使无取向电工钢铁损降低。随频率的增加,铁损增加,磁导率降低,特别是在高频下,铁损增加或磁导率降低的速率增大。     

提高0.10mm厚硅钢薄带的取向度

１　引　言众所周知，减薄取向硅钢带的厚度可有效地降低其铁损值。但是，应用以有利夹杂和以晶界能促使（１１０）结晶晶粒长大的成品取向硅钢为原料再制作成厚度为０．１５～０．１６ｍｍ以下时，要降低其铁损值是困难的。与此不同的是，以热轧板作原料，以两次冷轧法控制适当的压下率和热处理条件，生产出最终厚度为０．１０ｍｍ的取向硅钢薄带。这一方法的特征是成品中（１１０）晶粒成长的动力主要是利用表面能。另外，用二次冷轧法的取向薄带其［００１］方向的取向度与高磁感取向硅钢相比要显著低一些。现在的问题是，一方面进一步减…     

二次冷轧压下率对无取向电工钢薄带磁性能和织构的影响

研究了二次冷轧压下率对无取向硅钢薄带磁性能和织构的影响,结果表明:采用二次冷轧工艺时,55%左右的二次冷轧压下率能够获得磁性能优良的0.2 mm厚无取向硅钢薄带.当二次冷轧压下率高于55%后,成品钢带中对磁性能不利的r织构组分比例逐渐增强,特别是{111}<112>、{111)<110>织构.采用55%左右的二次冷轧压下率制造能获得{100}面织构和高斯织构比例都较高的产品,其铁损P1.0/400能够降低到10.6 W/kg,同时磁感B50能达到1.68T.     

热轧工艺对无取向硅钢组织结构和磁性能的影响

研究了热轧加热温度、终轧温度、卷取温度对w(Si)=1.50%无取向硅钢晶粒组织、织构演变、铁损和磁感的影响.结果表明,随着铸坯加热温度的提高,冷轧无取向硅钢成品晶粒尺寸减小,有利织构组分增加,铁损增加,磁感提高.提高终轧温度可以促进热轧板的再结晶,增加成品中有利织构组分,降低铁损,提高磁感.卷取温度对成品的晶粒大小没有显著的影响,但提高卷取温度能增加成品中有利织构组分,降低铁损,提高磁感.     

冷轧压下率对DQ级深冲带钢组织和性能的影响

研究了60%～80%冷轧压下率对3.5 mm CSP热轧板轧制的1.4～0.7 mm冷轧深冲带钢力学性能、组织和织构的影响。结果表明,随冷轧压下率由60%提高至80%,冷轧带钢的再结晶开始温度由560℃降至520℃,成品带钢组织细化;当冷轧压下率为74.3%时,成品DQ级带钢的深冲性能最佳。随冷轧压下率提高,成品深冲带钢△r值逐渐减小,这与成品带钢中{112}〈110〉织构取向函数值f(g)升高有关。     

冷轧压下率对薄规格取向硅钢冷轧和退火织构的影响

实验采用不同厚度的低温取向硅钢热轧板冷轧至0.18 mm。通过XRD分析冷轧板表面和中心层的织构,通过EBSD分析了脱碳板截面的织构。结果表明,冷轧样品表层和中心层,随着压下率增大,{111}面织构总含量有所减少,{100}面织构总含量有所增多;脱碳样品中{111}面织构明显增多,尤其是{111}〈112〉织构组分,{100}面织构明显减少,尤其是{100}〈011〉织构组分,{411}〈148〉织构组分也明显增多;脱碳样品中,随着压下率增大,晶粒尺寸逐渐减小。不利于二次再结晶发展的织构随着压下率的增大明显增加,同时有利的CSL晶界随着压下率的增加会稍有减少。     

0.20 mm薄规格取向硅钢的开发及关键工艺探讨

为开发磁性能优良的0.20 mm薄规格取向硅钢,对该取向硅钢的组织特征,不同冷轧压下率和高温退火气氛对磁性能的影响进行了研究。结果表明：所获得的0.20 mm薄规格取向硅钢成品组织二次再结晶完全,铁损（P1.7/50）为0.89 W/kg,磁感（J800）为1.906 T;热轧和常化1/8层的主要织构组分为Goss织构,冷轧织构为较强的{001}〈110〉,退火织构主要为{411}〈148〉,脱碳晶粒尺寸约为21.17 μm,Goss晶粒极少;0.20 mm薄规格取向硅钢合适的冷轧压下率为91.3 %;高温退火升温段合适的气氛为75% N2。     

冷轧厚度对3.0 %Si无取向硅钢组织及磁性能的影响

研究了冷轧厚度对3.0 %Si的无取向硅钢组织和磁性能的影响规律。结果表明：当冷轧厚度由0.35 mm减薄至0.27 mm时,平均晶粒尺寸由104 μm降低至89 μm ,P1.5/50由2.186 W/kg降低至2.139 W/kg,P1.0/400由16.978 W/kg降低至13.978 W/kg,涡流损耗占比随之降低,{112}〈110〉取向强度减弱而{111}〈110〉取向强度增加,B50由1.684 T降低至1.662 T。     

Effect of Thermomechanical Processing on Microstructure,Texture Evolution,and Mechanical Properties of Al-Mg-Si-Cu Alloys with Different Zn Contents

The effect of thermomechanical processing on microstructure, texture evolution, and mechanical properties of Al-Mg-Si-Cu alloys with different Zn contents was studied by mechanical properties, microstructure, and texture characterization in the present study. The results show that thermomechanical processing has a significant influence on the evolution of microstructure and texture and on the final mechanical properties, independently of Zn contents. Compared with the T4P-treated (first preaged at 353 K (80 °C) for 12 hours and then naturally aged for 14 days) sheets with high final cold rolling reduction, the T4P-treated sheets with low final cold rolling reduction possess almost identical strength and elongation and higher average r values. Compared with the intermediate annealed sheets with high final cold rolling reduction, the intermediate annealed sheets with low final cold rolling reduction contain a higher number of particles with a smaller size. After solution treatment, in contrast to the sheets with high final cold rolling reduction, the sheets with low final cold rolling reduction possess finer grain structure and tend to form a weaker recrystallization texture. The recrystallization texture may be affected by particle distribution, grain size, and final cold rolling texture. Finally, the visco-plastic self-consistent (VPSC) model was used to predict r values.

     

二次冷轧压下率对高牌号无取向硅钢组织结构和磁性能的影响

 研究二次冷轧压下率对于硅的质量分数为3.0%的无取向硅钢组织结构和磁性能的影响。结果表明：当第二次冷轧压下率从0变化至16.7%时,铁损逐渐增加,磁感逐渐降低。当第二次冷轧压下率大于16.7%时,随压下率的增加,铁损逐渐减小,磁感逐渐增加。当第二次冷轧压下率大于38%时,二次冷轧法所能获得的磁性能明显优于一次冷轧法。     

Influence of subsurface layers on texture and microstructure development in RGO electrical steel

RGO (regular grain oriented) electrical steel is produced by a two stage cold rolling process with intermediate annealing. In this study the influence of surface layers on the recrystallization behaviour is investigated. By controlled thinning of the sheets at different processing stages surface layers were removed single- and double-sidedly in successive steps of 1/10th of half thickness keeping the final thickness, as well as the 2nd cold reduction, constant. All specimens were processed to the final product relating to standard conditions and texture analysis as well as magnetic measurements being performed, indicating very sensitively any disturbance in Goss-texture development. A deterioration of Goss-texture sharpness only appears if a critical surface layer is removed from both sides of the sheet, no matter the processing stage at which the removal was performed. This result suggests a kind of “texture inheritance” due to a texture profile being present at hot strip with a strong Goss-texture at its surface layer. The observed detrimental effect on secondary recrystallization due to the surface removal can be explained by the texture and microstructure development during the processing of RGO electrical steel. Thus the complete texture and microstructure development was investigated first and explained relating to theoretical models of texture development during deformation and leading to a new understanding of what was called “texture inheritance”.     

Effect of Cold Rolling Reduction Ratio on Microstructure and Magnetic Properties of Secondary Cold-Rolled High-Grade Nonoriented Silicon Steel

Trial production of 0.25 mm-thick thin-gauge high-grade nonoriented silicon steel with a Si content of 3.5% by the secondary cold rolling process is studied. The recrystallization microstructure and magnetic properties are systematically studied by the microstructure, texture evolution, and the effect of two-stage cold rolling reduction ratios (37.5–70.5%) during the whole process. The results show that the magnetic induction intensity B₅₀₀₀ first increases and then decreases; the iron loss first decreases and then increases at the frequencies of 50 and 400 Hz with the reduction of the cold rolling reduction rate in the second stage. The cubic and Goss texture of the finished annealed sheet has the highest strength when the reduction ratio of the second stage cold rolling is 58.3%. The highest magnetic induction intensity, B₅₀₀₀ = 1.671 T. Lowest iron loss, P_1.0/50 = 0.83 W kg⁻¹, P_1.5/50 = 1.98 W kg⁻¹, and P_1.0/400 = 11.94 W kg⁻¹, respectively.     

Influence of the Cold Rolling and Annealing Sequence on the Ridging Behaviour of Ti‐Stabilized 18% Cr Ferritic Stainless Steel

The influence of the cold rolling and annealing sequence on the ridging resistance and the crystallographic texture distribution of AISI 439 type ferritic stainless steel was studied in order to determine optimal processing conditions for surface quality improvement. In the present study, the effect of two sequences of cold rolling and annealing were analysed: a single cold rolling and annealing, and an interrupted cold rolling with an intermediate and a final anneal. In the conventional single step cold rolling, the ridging resistance was found to deteriorate with increasing cold reduction ratio. For a fixed total cold reduction ratio in the two stage cold rolling, ridging was less pronounced when a higher reduction was applied in the second step. Band‐like clusters of grains with similar crystallographic orientations were observed in the mid‐thickness of sheets with severe ridging. The results show that severe ridging is related to the presence of band‐like clusters of 〈111〉//ND oriented grains. The two stage cold rolling was found to result in less band‐like clusters and an improved surface quality.     

Effect of Through‐Thickness Macro and Micro‐Texture Gradients on Ridging of 17%Cr Ferritic Stainless Steel Sheet

In order to study the formation of ridging in ferritic stainless steel (FSS) sheets, the evolution of the crystallographic texture was investigated by macro and micro‐texture measurements throughout the thickness of the sheets. The as‐received hot band material displayed a pronounced through‐thickness texture gradient with a strong rotated cube orientation in the sheet center layer. The initial texture of the hot band had a high impact on the formation of the cold rolling texture and on the final recrystallization texture. Modification of the cold rolling texture by means of cross‐rolling led to an improvement of the macro and micro‐textures after final recrystallization annealing, which gave rise to an enhanced sheet formability in FSS. Tensile tests of specimens with half thickness revealed that ridging formed in the sheet center was much stronger than that in the surface. This observation was attributed to the more frequent formation of orientation colonies in the sheet center when compared to the sheet surface.     

剪切变形方式对取向硅钢织构和磁性的影响

采用异步轧制将经过一次正常冷轧和中间退火的０．７５ｍｍ厚的工业取向硅钢板材异步轧至不同的厚度,然后进行工业退火,研究剪切变形方式对板材织构和磁性的影响。结果表明：异步轧制下,作用于差轧区上的剪切应力能够有效地改善板材心部的织构组态,并在板材亚表层附近相对较大的区域内形成了理想的冷轧织构;退火后板材内重新形成了取向集中的Ｇｏｓｓ织构,其磁性均不低于常规轧制。