钢厂
低温高磁感取向硅钢常化工艺中间冷却制度的研究
借助电子背散射(EBSD)技术对AlN为主抑制剂的Hi-B取向硅钢常化工艺的中间冷却制度进行了研究。结果表明:常化后试样均发生了完全再结晶,在60℃/s冷速下组织最均匀;在合适的冷却制度下常化板表层保留了强的Goss织构,它深入到1/4厚度处,并且形成对Goss织构有利的强{554}<225>织构。 The intermediate cooling system of Hi-B oriented silicon steel with AlN main inhibitor in normalizing process was studied by means of electron back diffraction(EBSD) technique. The results show that:the specimens after normalizing are fully recrystallization, and the microstructure is most uniform under the intermediate cooling rate of 60℃/s; under suitable cooling system, normalized plate surface retains strong Goss texture, it penetrates into the 1/4 thickness of the plate and forming strong {...
修正GTN模型及其在预测硅钢冷轧边裂中的应用
考虑剪应变对微孔洞损伤演化的影响,对GTN损伤模型的损伤演化机制进行修正,建立了适用于不同应力三轴度水平的损伤模型。结合隐式应力更新算法和显式有限元计算,采用VUMAT子程序实现了修正GTN模型在有限元软件ABAQUS中的数值计算。通过模拟纯剪切和剪切-拉伸两组试样的损伤演化和断裂行为,验证了修正GTN模型在不同应力三轴度承载条件下的有效性。运用修正GTN损伤模型模拟含边部缺口的带钢在轧制过程中裂纹的萌生和扩展行为,模拟结果与实验相一致,表明该模型可有效地用于带钢缺陷在轧制过程中扩展行为的分析和预测。模拟和实验结果表明,带钢边部缺口在轧制过程中,缺口前沿和后沿均会萌生裂纹,且后沿裂纹扩展更为明显。 Considering the effect of shear strain of micro-void on damage evolution, a modified GTN model applicable to various stress triaxiality conditions is proposed by modifying the damage evolution mechanism of the GTN damage model. The modified model is implemented in commercial finite element software ABAQUS by combining the implicit stress update method with an explicit finite element solving algorithm and through the user-defined material subroutine VUMAT. The damage evolution and the failure pro...
奥氏体化温度对高碳含硅钢等温转变的影响
采用XRD物相分析、金相组织观察及TEM精细组织分析研究了奥氏体组织结构状态对Fe-0.88C-1.35Si-1.03Cr-0.43Mn钢中温等温相变鼻温和孕育期的影响,以及不同温度奥氏体化后240℃等温20 min试样的组织结构特征。试验发现,随着奥氏体化温度的升高,中温等温开始转变的鼻温移向更低温度并且相变孕育期缩短;不同温度奥氏体化后同为240℃等温20 min处理,虽然均形成由贝氏体铁素体亚条平行排列构成的束状贝氏体组织,但贝氏体组织的精细结构状态不同,突出的差别在于对应低温奥氏体化贝氏体亚条端部边界具有凸起结构,而对应高温奥氏体化贝氏体亚条端部边界较为平齐且呈现楔形结构。不能简单地以马氏体切变机制认识试验钢中贝氏体组织的形成。 The influence of austenitization temperature on the incubation period and the bainitic phase transformation behaviour in high-carbon silicon steel has been investigated using X-ray diffraction(XRD), optical microscopy and transmission electron microscopy(TEM). The microstructure characteristics of the isothermal transformation(240 ℃, 20 min)products were also studied. It was found that the nose temperature of bainite transformation and incubation period decreased with the increasing austenitizin...
硅钢在连续退火机组浪形缺陷的控制
为了消除硅钢在连续退火机组产生的浪形缺陷,对浪形缺陷产生的主要原因进行了分析。制定了相应控制措施,对炉内带钢张力、冷却段输出、碳套辊与带钢的同步性、无氧化炉燃烧状态等参数进行了调整;在生产组织上安排高低牌号宽窄规格穿插生产、定期更换碳套辊等,实施后效果明显。 The main cause leading to waviness defects of silicon steel is analyzed in order to eliminate the waviness defects of silicon steel in continuous annealing line.And thus corresponding measures for controlling these defects are made by means of adjusting these parameters such as the tension of silicon steel coils in continuous annealing furnace,the output in cooling section and the combusting condition of the non-oxidation furnace as well as keeping the synchronization between carbon sleeved roll...
冷轧无取向硅钢冶炼过程炉渣分析
对冷轧无取向硅钢在冶炼过程中各个工序的顶渣进行了检测,分析了顶渣变化原因,并得出结论:硅钢生产宜采用复吹转炉,以降低吹炼终点渣中TFe含量,进而减轻对精炼的压力;使用低S、低Al2O3含量中间包覆盖剂;RH脱氧及合金化顺序采用先加硅铁后加铝;首罐宜经LF提温并降低渣中TFe。 The top-surface slag used for the various production processes in smelting coldrolled non-oriented electrical steel is tested and based on tested results the cause of the top surface slag change is analyzed.So it is concluded that the combined blown converter is more suitable to be used for smelting electrical steel in order to reduce the content of TFe in slag at blow end point and then much better results can be achieved during the period of refining.Secondly the tundish flux contenting low co...
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,...
高牌号无取向电工钢热轧板常化退火组织的EBSD分析
借助于EBSD对比研究了常化退火对高牌号无取向电工钢热轧组织和织构演变的影响,分析了常化退火对热轧板各厚度层织构的演变规律。结果表明,常化退火改善了热轧组织的均匀性,并弱化了热轧变形的γ纤维织构。升高常化退火温度,可增大热轧板的晶粒尺寸,提高{100}和{110}织构组分占有率,有利于提高无取向电工钢成品板的磁性能。 Effects of normalizing annealing on microstructure and texture of high-grade non-oriented electrical steel hot-rolled sheet were investigated by EBSD. Emphasis was put on the effects of normalizing annealing on texture evolution in the sheet thickness. The results show that the hot-rolled microstructure homogeneity is improved and the γ-fiber texture is weakened by normalizing annealing treatment. The grain size of hot-rolled sheet and intensity of the {100} and {110} favorable texture can be in...
正火对双辊薄带连铸5.28%Si-1.11%Al无取向高硅钢磁性能的影响
采用双辊薄带连铸工艺试制了2.6 mm厚5.28%Si-1.11%Al高硅钢薄带,对比了1050℃×5 min正火及不正火铸带280℃冷轧至0.5 mm后,再经900～1100℃退火的磁性能。结果表明,高硅钢铸带显微组织为等轴晶组织,正火后铸带边部晶粒长大,中心层晶粒变化较小。成品中析出物主要为较粗大的AlN和AlN+MnS复合析出物,尺寸为0.5～2.5μm。与不正火试样相比,正火试样成品铁损大幅降低,磁感小幅下降;随退火温度的升高,两种工艺下铁损和磁感都是先降低后升高,在1050℃出现最低值。 2.6 mm thickness 5.28% Si-1.11% Al non-oriented high silicon steel was produced by twin roll thin strip casting.Magnetic property of the strip un-normalized and normalized at 1050 ℃×5 min was contrasted after cold rolled to 0.5 mm at 280 ℃ and 900-1100 ℃ final annealing.The results show that microstructure of the strip is equiaxed crystal.The surface grain is coarsened and the center layer grain has little change of the normalized strip.The main precipitates are AlN and MnS+AlN with 0.5-2.5 μm s...
剪切方式对冷轧无取向硅钢边部磁畴的影响
为提高无取向硅钢导磁性能,研究了不同剪切方式对无取向硅钢剪切处磁畴结构的影响。利用纳米磁流体观测无取向硅钢剪切后边部磁畴结构。结果表明,硅钢无论在机械剪切还是线切割后的边部磁畴都会发生不同程度的改变:线切割对边部磁畴结构改变较小,边部磁畴分布均匀且连续,在距边缘0～20μm范围内出现磁畴宽度变小现象;机械剪切对磁畴的改变较为严重,剪切处磁畴零乱且不连续,在距边缘20μm处仍难以观察到完整的磁畴结构。 The effects of different shearing modes on magnetic domain structure of cold rolled non-oriented silicon steel are studied in this paper.The magnetic domain of cold rolled non-oriented silicon steel is observed by nanometer magnetic fluid pattern method.The results show that the edge magnetic domain structure will be changed by mechanical shear and wire-electrode cutting,the variation of edge magnetic domain structure wire-electrode cutting edge is very small,the magnetic domain structure is wel...
