钢厂
常化工艺对Si的质量分数为1.6%的无取向电工钢磁性能的影响
研究了常化温度、常化时间及常化后冷却速度对Si的质量分数为1.6%的无取向电工钢成品磁性能的影响。结果表明:在850~1 050℃范围内,随着常化温度的升高,成品铁损先减小后增大,成品磁感应强度先增大后减小;当常化温度为1 000℃时,成品平均铁损最低,平均磁感应强度最高;常化时间从3min延长到7min时,成品铁损先减小后增大,成品磁感应强度则呈单调下降趋势;随着常化冷却速度的降低,成品铁损先减小后增大,成品磁感应强度则呈单调增大趋势;对于Si的质量分数为1.6%的无取向电工钢,最佳的常化制度为:在1 000℃进行常化,时间5min,常化后空冷。对热轧板进行常化后,热轧板发生了不同程度的再结晶和晶粒长大。提高常化温度、延长常化时间、降低冷却速度,都能使常化板晶粒粗化,进而粗化成品板晶粒,改善磁性能。通过扫描电镜观察发现,成品板中析出物主要为AlN和MnS的复合析出物,以及少量的单独析出的AlN和MnS,而常化工艺主要是通过粗化析出相,减少细小析出相数量,从而减少对晶界钉扎作用来改善成品磁性能。 The effects of normalizing temperature,normalizing time and cooling rate after normalizing on magnetic properties of non-oriented electrical steel with mass fraction of Si of 1.6% were investigated.The results show that core loss of product decreases first and then increases,while magnetic induction increases first and then decreases with the increase of normalizing temperature from 850 to 1 050℃.Average core loss of product is the lowest and average magnetic induction is the highest when normal...
无取向硅钢热轧边裂的形成原因
利用加热炉模拟、动态再结晶以及热模拟等试验方法以及扫描电镜、金相显微镜等分析观察手段对无取向硅钢边裂的成因进行了探讨。结果表明,长时间加热使得板坯边部晶粒异常长大,晶界氧化并脱碳,轧制过程中边部温度过低,动态再结晶过程变弱,使得板坯边部延伸性能变差,是导致硅钢边裂的主要原因。建议通过适当降低铸坯加热温度、缩短保温时间、提高终轧温度来改善硅钢边裂缺陷。 The behaviors of high temperature oxidation,dynamic recrystallization,and hot ductility,microstructure evolution were investigated on the non-oriented electrical steel sheets to discuss the formation of edge crack.The key causes of cracking was found to be the coarse as-cast microstructure,grain boundary oxidation and decarburization in reheating furnace,as well as reduced temperature at strip edge region during hot rolling process resulting in reduced hot ductility and lack of enough dynamic re...
双辊连铸无取向硅钢铸带特征及常化作用研究
双辊连铸技术是冶金及材料领域内的一项前沿技术,对于生产高品质硅钢具有独特优势.本实验研究了一种双辊铸轧w[Si]=4.5%的无取向硅钢,考察其铸态和常化处理后样品的组织、织构及析出相尺寸特征.结果表明:铸带组织以与铸带法向成5~20(°)倾角的柱状晶为主,晶内存在少量0.3~0.4μm的AlN析出相,铸带织构以λ(<001>//ND)织构为主,表层织构漫散.950℃/10 min常化处理后,析出相尺寸增大,表层λ织构增强. As an advanced technique of metallurgy and material science,twin- roll strip casting has unique advantages for producing high quality silicon steel. The present study was aimed at a 4. 5% Si non- oriented electrical steel for analyzing the structure,texture and the size of precipitates at the initial and normalized state. The results revealed that the initial structure mainly consisted of columnar grains with 5 ~ 20( °) angle to the normal of cast strip,and some AlN precipitates of 0. 3 ~ 0. 4 μ...
电工钢铸锭内析出相粒子特征及回溶行为
利用场发射电镜及能谱仪研究了取向电工钢薄、厚板坯铸锭中不同区域的析出相差异,确定了MnS、AlN及Fe3C的析出顺序和形貌特征。结果表明AlN以先析出的MnS为形核核心,形成粗大微米级的复合析出相。针状Fe3C既可以在复合析出相表面形成也可以在基体中单独出现,主要受冷却速度的影响。在1250℃保温1～2 h,AlN、Fe3C均可完全回溶,但部分MnS仍不回溶。MnS尺寸随着保温时间延长而增大。导致热轧板中沿轧向分布的粗大MnS,减弱了粒子钉扎力。 Precipitates in thin and thick slabs of electrical silicon steel were investigated by means of field emission SEM and EDS analysis.The precipitation sequence and the morphology of MnS,AlN and Fe3C particles were identified.AlN particles are observed to be nucleated on surface of MnS forming micron-meter-sized complex particles.Acicular Fe3C can precipitate on surface of the complex MnS/AlN particles or directly from matrix depending on cooling rate of the slabs.After holding at 1250 ℃ for 1-2 h,...
电感耦合等离子体质谱法测定硅钢中痕量铝钼钒钛铌
研究了应用电感耦合等离子体质谱(ICP-MS)同时测定硅钢中痕量铝、钼、钒、钛、铌元素的分析方法。通过条件试验对测量参数进行了优化,确定RF功率1 400 W,泵速30rpm,采样深度140,雾化压力0.90。样品采用硝酸分解,以Be、Y混合内标校正了测量过程中高基体引起的信号漂移。根据测量时存在的质谱干扰情况,选择同位素27 Al、98 Mo、51 V、47 Ti和93 Nb作为测定同位素,同时通过调节仪器参数使得双电荷离子和氧化物离子的产率最低,以减少其带来的干扰。采用基体匹配法配制校准溶液,以标准加入法建立工作曲线,并扣除试剂空白。该方法各元素的测定下限均可达到1μg/g。用于硅钢标准样品的测定,所得结果与参考值完全吻合,各元素的RSD小于5.2%。 A method for the determination of trace aluminum,molybdenum,vanadium,titanium and niobium in silicon steel by inductively coupled plasma mass spectrometry(ICP-MS) was described.A series of single parameter condition experiment was conducted.The optimized operation parameters with RF power 1 400 W,turbo pump rate 30 rpm,sampling depth 140 and nebulizer pressure 0.90 were obtained.The samples were dissolved by HNO3,and the Be and Y mixing internal standard were used to eliminate the signal drift c...
低温取向硅钢热轧态组织及织构的研究
利用热模拟试验机、光学显微镜和X射线衍射仪对Fe-3.2%Si低温取向硅钢热轧工艺参数对组织及织构的影响进行了研究。结果表明,Fe-3.2%Si硅钢在1110℃粗轧、880℃终轧,轧后以10℃/s的速度冷却到550℃卷取,然后空冷到室温,热轧硅钢板沿板厚方向的显微组织不均匀性显著,对后续发展完善的二次再结晶有重要作用。无论是热轧板,常化板还是冷轧板,它们的织构集中分布在γ取向线上,γ取向线的织构除取向密度不同外,织构种类是一致的,这说明γ取向线上织构是有继承性的。从热轧到常化,织构取向密度显著减小,经二次冷轧后,织构密度又显著升高,可见,轧制变形有助于织构的形成并使织构强度升高。 The influence of hot-rolled process parameters on the microstructure and texture of Fe-3.2%Si low temperature hot rolled grain-oriented silicon steel were researched by hot simulation experiment machine,light microscope and X-ray diffractometer.The results show that,Fe-3.2%Si silicon steel is rolled by the technology with a temperature of rough rolling of1110℃,finish rolling of 880℃,coiling with the speed of 10℃ /s,and then cooled to room temperature with air.The microstructure of hot-rolled sil...
冷轧无取向硅钢横向厚差控制
冷轧中中低牌号的无取向硅钢多采用万能凸度轧机(Universal crown mill,UCM)生产,其板形好坏受制于UCM轧机板形调节手段的协调使用。为掌握UCM轧机的板形控制特点,建立基于二维变厚度有限元的辊系弹性变形和基于三维差分的轧件塑性变形的六辊轧机耦合模型,对UCM轧机的板形调控性能进行详尽的分析,包括工作辊和中间辊弯辊、中间辊窜辊的调控功效、辊间接触压力分布等。在此基础上,提出可用指导生产的板形控制策略,指出UCM轧机在横向厚差控制方面的不足。针对工业生产中UCM轧机轧制无取向硅钢横向厚差大的问题,在大量仿真计算的基础上,开发具有高次曲线函数的边部变凸度(Edge variable crown,EVC)的工作辊。采用该工作辊后,各种品种的无取向硅钢的横向厚差不大于10μm的百分比由24%提高到99%,横向厚差的均值小于6μm,远小于之前的13μm。 Medium-low grade non-oriented silicon steel is rolled often by universal crown mill(UCM) during cold rolling.Its shape quality is dependent on the coordinated control of several shape adjustment devices of UCM.In order to understand the shape control characteristics of UCM,coupling model of six-high rolling mill,based on two-dimensional varying thickness finite element rolls elastic deformation model and three-dimensional finite difference strip plastic deformation model,is setup for the detaile...
稀土铈含量对1.2%Si无取向电工钢组织、织构及磁性能的影响
在实验室模拟CSP流程制备了不同含量稀土铈(质量分数0~0.018%)的1.2%Si无取向电工钢,并对其进行1 000℃×5min的再结晶退火处理,研究了铈质量分数对无取向电工钢夹杂物、显微组织、再结晶织构和磁性能的影响。结果表明:随着铈质量分数的增加,微细夹杂物数量、再结晶晶粒尺寸、{100}和{110}织构组分、磁感应强度先增后减,{111}织构组分、铁损先减后增;铈的质量分数为0.005 1%时,钢中的夹杂物数量最少,再结晶晶粒尺寸最大,有利织构最多,磁性能最优,铁损P15/50为3.253W·kg-1,磁感应强度B50为1.751T。 Non-oriented electrical steels containing different contents rare earth Ce element(0-0.018wt%) were prepared in the laboratory by simulated CSP(compact strip production)process,and then recrystallization annealing at 1 000 ℃ for 5 min were performed,the effects of Ce content on inclusion,microstructure, recrystallization texture and magnetic properties of non-oriented electrical steels were studied.The results show that with the increase of Ce content,the amounts of fine inclusion,the size of re...
