铁素体不锈钢铸轧薄带凝固组织对冷轧退火带晶粒簇的影响

 研究了Cr17铁素体不锈钢铸轧薄带凝固组织对其冷轧退火带晶粒簇、成形性和皱折特性的影响。利用电子背散射衍射技术对Cr17铁素体不锈钢铸轧薄带及相应的冷轧退火带进行了显微织构分析。结果表明：①Cr17铁素体不锈钢铸轧薄带冷轧退火带的晶粒簇依赖于初始铸轧薄带的凝固组织类型;②柱状晶组织的铸轧薄带具有显著的{001}∥ND晶体取向特征,而等轴晶组织的铸轧薄带晶体取向随机、分散;③等轴晶组织铸轧薄带比柱状晶组织铸轧薄带的冷轧退火带具有更少的{001}<110>晶粒簇和更多的{111}<112>、{111}<110>晶粒簇;④铸轧薄带的等轴晶组织比柱状晶组织有利于提高冷轧退火带的成形和抗皱性能。     

薄带连铸取向硅钢退火组织及织构演变研究

研究了薄带连铸取向硅钢的铸带、冷轧、脱碳退火的组织及织构。研究表明:取向硅钢铸带由铁素体及细碳化物组成,其中表层为细小等轴晶,心部为粗大等轴晶,次表层为粗大柱状晶。铸带主要织构为{001}织构;冷轧组织为拉长的纤维组织,冷轧织构主要为较强的α和γ纤维织构;脱碳退火组织主要为细小的等轴晶,织构主要为弱α和γ纤维织构组分。     

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.     

CSP无取向电工钢50 W600组织及织构演变研究

文章研究了CSP无取向电工钢50W600在热轧、冷轧、退火过程组织、织构演变情况,研究结果表明:铸坯为柱状晶组织;热轧板沿厚度方织构是不均匀的,表层主要织构为黄铜织构;脱碳退火板为再结晶组织,平均晶粒尺寸50μm,主要为γ纤维织构。     

GCr15轴承钢大方坯微观组织数值模拟

以某钢厂GCr15钢大方坯为研究对象,采用ProCAST软件建立凝固数学模型,在此基础上采用CAFE模型对铸坯凝固组织进行模拟,研究了过热度、拉速和二冷强度对铸坯凝固组织的影响。结果表明:过热度对铸坯凝固组织影响较大。随着过热度的提高,同一位置柱状晶区平均晶粒半径增大,柱状晶区增大,中心等轴晶比例减小,柱状晶向等轴晶转变延后,过热度由40℃降低至10℃时,中心等轴晶率增加21.14%。拉速和二冷强度对铸坯凝固组织影响较小。随着拉速的提高或二冷强度的降低,柱状晶区减小,中心等轴晶比例增大,柱状晶向等轴晶转变提前,但其变化并不明显。在实际生产过程中可以通过降低过热度来细化铸坯凝固组织晶粒。     

稀土Ce对取向硅钢铸坯及热轧态组织的影响

文章介绍了稀土Ce对取向硅钢铸坯组织及热轧态组织的影响。采用冷酸低倍及光学显微镜观察有无稀土铸坯及热轧态组织,对比分析稀土的作用。结果表明,稀土Ce可以改善取向硅钢铸坯组织,增加等轴晶比例,细化部分柱状晶。稀土Ce作为第二相粒子,起到钉扎作用,热轧时阻止晶粒过度长大,细化晶粒,使再结晶晶粒增多。     

凝固组织对超低碳铁素体不锈钢皱褶和深冲性的影响

为了研究凝固组织对超低碳铁素体不锈钢成形性的影响,采用XRD和SEM等分析手段详细研究了材料的皱褶和深冲性能。研究发现:相对于等轴晶的试样,柱状晶试样展示了更高的皱褶高度,这主要同柱状晶试样中存在明显的晶粒簇有关;经最终的再结晶退火后,等轴晶试样也展示了更好的深冲性能,这同等轴晶试样形成了强烈的γ纤维织构紧密相关。     

薄带连铸Cr17铁素体不锈钢的织构演变

以具有不同初始组织的Cr17铁素体不锈钢双辊连铸薄带为实验材料,分别进行相同的冷轧及退火处理,对织构演变进行了对比研究.结果表明:织构演变与薄带的初始组织、织构密切相关.柱状晶薄带具有显著的(001)//ND织构,等轴晶薄带则具有微弱的随机织构;两者经冷轧后都形成了较温和的α纤维织构及较均匀的γ纤维织构,但是,后者的α,γ纤维织构明显强于前者;经再结晶退火后,两者都能形成较均匀的γ纤维再结晶织构,但后者的γ纤维再结晶织构明显强于前者.     

连铸坯凝固组织均质化技术的研究现状及进展

造成连铸坯宏观偏析的最主要原因是连铸坯在外部强冷条件下形成发达的柱状晶组织,消除宏观偏析的根本途径是有效控制铸坯的凝固过程,减少铸坯中柱状晶比率,提高等轴晶率。文中对国内外提高铸坯等轴晶率的应用研究现状进行了系统的总结,在介绍各类提高铸坯等轴晶率应用研究的基础上,介绍了最新的提高铸坯等轴晶率的方法-振动激发金属液形核技术,对其在连铸中的应用进行了展望。     

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.     

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.     

Effect of Processing Condition on Texture and Drawability of a Ferritic Rolled and Annealed Interstitial-Free Steel

The processing conditions of the texture formation and deep drawability of a Ti-IF steel strip hot-rolled in ferritic region and subsequently annealed were investigated. The r-value increases with the decrease of reheating temperature, and finish rolling temperature and the increase of reductions in ferritic region. For lubricated ferritic rolling and annealing, the r-value is raised up to 1.75, and elongation rate is over 50% at the finish rolling temperature of 650 ℃, which is suitable for DDQ grade products. However, the r-value is below 1.0 in the case of unlubricated rolling. The X-ray diffraction was used to analyze the textural characteristic of samples. For samples subjected to lubricated rolling and annealing, the strong { 111 }//ND recrystallization texture is distributed homogeneously along the thickness direction, and the intensity of { 110} recrystallization texture is very low even in surface. However, for unlubricated samples, the {111} texture is distributed inhomogeneously and is weak along the thickness direction, and （110}//ND recrystallization texture is strong, which deteriorates the formability.     

00Cr17Ti热带退火对冷轧薄板表面皱折的影响

 通过对00Cr17Ti经热带退火、不经热带退火两种工艺的冷轧板进行对比试验,在分析显微组织、织构的基础上,研究了热带退火对00Cr17Ti薄板表面皱折的影响。研究结果表明：与不经热带退火相比,经热带退火能使成品薄板的表面皱折大大减轻,最大粗糙度仅为12.06 μm,平均粗糙度仅为1.27 μm。两种工艺的成品板表面皱折程度的不同是由两者在显微组织、微织构上的差异造成的。与不经热带退火相比,经热带退火的成品薄板在板厚方向具有较均匀的组织,板宽方向的织构梯度较小,晶粒簇较间断、细窄、分散,所有这些使得成品薄板的表面皱折大大减轻。为了满足用户对薄板表面质量的严格要求,对热轧带进行退火是很有必要的。     

热带退火对00Cr17Ti薄板成形性能的影响

 通过对00Cr17Ti经热带退火、不经热带退火两种工艺的对比试验,在分析显微组织、织构、值和ΔR值的基础上,研究了热带退火对00Cr17Ti薄板成形性能的影响。研究结果表明：与不经热带退火相比,经热带退火能使00Cr17Ti薄板的值提高约0.2,但是,ΔR值会增大约0.7。这是由两种工艺的成品薄板在显微组织、织构上的差异造成的。与不经热带退火相比,经热带退火的成品薄板具有更大的晶粒尺寸、更加均匀的组织以及更强的{111}再结晶织构,这使值提高,但是,其{111} γ取向线上各织构组分强度的非常不一致却导致ΔR值明显偏大。     

Texture Evolution of Columnar Grains in Electrical Steel During Hot Rolling

Columnar grains in cast slabs of electrical steel show strong anisotropy in grain orientation and morphology and thus influence the subsequent microstructure and texture after hot rolling significantly. The texture evolution of hot rolled sheets containing initial columnar grains with their <100> directions approximately parallel to the rolling direction (RD), transverse direction (TD) and normal direction (ND) of the hot rolled sheets was investigated by using EBSD technique. The results indicated that, whatever the initial texture of the columnar grains was, typical Goss, brass-type and copper-type shear texture component could develop in shear-deformed surface region. The copper-type texture formed under the maximum shearing force with the fine, sheared or dynamically recrystallized grains, and Goss grains were mainly elongated and deformed grains, while brass grains behaved between them. Additionally, the rotating relationship of the three types of shear textures was different due to the restriction of grain boundaries. In homogenously deformed center region, the RD sample contained more {112} <110> grains, and TD sample was covered by {100} textures such as {100}<011> and {100}<021> with coarse grains, while the ND sample developed many {100}<011> grains which were attributed to more {100} grains in the initial sample. Remarkable texture transition occurred on both sides of grain boundaries when {110} grains were adjacent to α-fiber texture grains. It was found that significant texture gradient and preferred distribution of rotating axis existed in the soft orientation grains on the α-fiber when the grains neighbored hard grains on γ-fiber.     

Structure and Texture Formation During Single and Double Cold Rolling and Annealing Processes for Nb+Ti Added Interstitial-Free Steels

 The structure and texture formation for single cold rolling (SCR) with annealing and double cold rolling (DCR) with annealing were investigated based on optical microscope and X-ray diffraction (XRD) with a Nb+Ti bearing interstitial free (IF) steel. The results indicated that DCR recrystallization grain was smaller than that of SCR sample and double cold rolling process resulted in better mechanical properties than those resulted from single cold rolling process with the same total reduction conducted. The plastic strain ratio increases from 2. 23 for single cold rolling process to 3. 2 for double rolling process. The fish-bone structure was observed in all SCR and DCR samples. DCR annealed sample is made up of equiaxed grains of almost uniform size, whereas SCR annealed sample shows a duplex grain structure, consisting of both large and small-sized grains. (Ti+Nb)C and Fe(Ti+Nb)P type precipitates were very rarely observed in SCR annealed and DCR annealed steels. The intensity of {111}∥ND for the DCR annealing was higher than that for SCR annealing.     

Textures and Properties of Hot Rolled High Strength Ti-IF Steels

The texture evolution in a high strength Ti-IF steel during the processing of hot rolling, cold rolling, and annealing is studied. For comparison, both ferrite rolling and austenite rolling are employed. It is found that the texture type is the. same after ferrite rolling and austenite rolling, but the texture intensity is much higher in the ferrite rolled sample. Furthermore, texture characteristics at the surface are absolutely different from those at the mid sec tion in both ferrite rolled and austenite rolled samples, as well as under the cold rolled and annealed conditions. The shear texture { 110 } 〈001 〉 disappears and orientation rotates along { 110 } 〈001 〉→ { 554 } 〈 225 〉→ { 111 } 〈 112 〉→{111}〈110〉→{223}〈110〉 during cold rolling. Compared to the austenite rolled sample, the properties of the cold rolled and annealed sheet which is subjected to ferrite rolling are higher.     

退火工艺对DC04汽车板再结晶组织和织构的影响

以酒钢CSP工艺DC04冷轧汽车板为原料,通过实验室模拟退火工艺,采用OM、EBSD、ODF技术,研究退火工艺对其组织和织构特征的影响。结果表明,DC04汽车板退火组织为铁素体和少量渗碳体,575℃退火1h再结晶开始,730℃退火1h后再结晶较为充分,并随着退火时间的延长,铁素体晶粒长大。不同压下率的DC04冷轧板和退火板中,主要织构均为bcc金属中典型的α(<110>//RD)纤维织构和γ（<111>//ND）纤维织构。随着压下率增加,{111}<112>织构的取向密度明显大于{111}<110>织构的取向密度。730 ℃退火后,低压下率67%的退火板织构中有微弱的{001}<110>取向,但随着压下率增大,这种织构逐渐消失,而形成较强的{111}<112>、{111}<110>有利织构。增加变形量有利于获得有利的{111}织构而抑制不利{001}织构的生成,从而提高DC04的深冲性能。     

CSP工艺0.04C钢热轧板冷轧-退火织构的演变

通过实验室4辊轧机和保护气氛管式退火炉，对0．04C钢CSP工艺生产的3姗热轧板进行冷轧（至0．8mm）和退火试验，并用蚀坑法对退火试样进行织构分析；同时对包钢薄板厂CSP3mm热轧板冷轧的1．2姗板卷退火试样进行了X-射线检测。结果表明，1．2mm SPCC冷轧板退火织构表层有较弱的{111}织构组分，中心层没有发现有利于提高钢的深冲性能的{111}织构。1．2mm板卷退火试样{111}／{100}取向密度比为2．0～3．0，与实验室蚀坑法的试验结果一致。