钢厂
单道次热轧对Fe-1.5Si硅钢氧化层形貌的影响
将Fe-1.5Si硅钢试样分别在1 000~1 200℃空气条件下氧化30 min,观察发现在1 000℃和1 100℃时,氧化层与基体界面处存在硅酸亚铁,而当温度为1 200℃时,硅酸亚铁不但存在于界面处,同时也存在于氧化层中.将各温度下得到的带有氧化层的试样进行单道次热轧试验,压下率分别为10%和30%,发现1 000℃和1 100℃时,较高的压下率使氧化层破碎更加严重,但是单道次热轧未能改变氧化层的结构;当温度为1 200℃时,由于液态的硅酸亚铁的出现,单道次热轧能够将界面处的液化的硅酸亚铁层挤压到氧化层中,消除了硅酸亚铁层的钉扎基体的效应,改善了氧化层与基体界面的平直度. Specimens of Fe-1.5Si silicon steel were oxidized at 1 000 ~ 1 200 ℃ in air for 30 min.At 1 000 ℃ and 1 100 ℃ fayalite was observed at the scale/substrate interface.While at 1 200 ℃fayalite was found both at the scale/substrate interface and at the outer oxide layer.Then after the single-pass hot rolling process,with the compression ratio of 10% and 30%,it was found that at 1000 ℃ and 1 100 ℃,higher compression rate accelerated the broken of the scale layers,but the scale structure was not affec...
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...
电工钢中柱状晶热压缩时取向的变化及对析出的影响
利用电子背散射衍射(EBSD)技术和场发射电子扫描显微镜(FESEM)研究了电工钢中柱状晶不同初始取向50%热压缩变形后的演变规律及其对粒子析出行为的影响。结果表明:〈100〉晶粒形变后仍为〈100〉取向,只发生绕ND∥〈100〉方向的转动,具有遗传性,粒子析出数量少。柱状晶长轴与压缩轴的偏转度增加,取向的稳定性变差,超过40°,可形成〈111〉取向,期间发生复杂的滑移系交互作用,产生较高的缺陷密度,促进粒子析出。MnS粒子主要在晶内析出,变形温度高、形变量低,粒子均无法充分析出。回复时,形变晶粒内高的储能和缺陷密度是促进粒子进一步析出的必要条件。 The evolution of initial orientations and their influence on precipitation of columnar-grained electrical steel after 50% hot compression deformation were investigated by electron backscatter diffraction technique and field emission scanning electron microscopy.The results indicate that the〈100〉orientated columnar grains remain still〈100〉after hot compression deformation,with only rotation around ND parallel to〈100〉direction,with heredity,and less precipitation.As the deviation angle between the...
电工钢冶炼过程中硫含量控制
介绍了攀钢冶炼电工钢过程硫含量变化以及过程回硫、增硫情况,采取针对性措施,如:提高铁水装入量、转炉采用石英砂代替复合造渣剂造渣、RH脱硫等,降低钢中硫含量。结果表明:采取相应措施后,电工钢炼成率大幅提高,成品w[S]≤0.008%的比例由改进前的62%提高到92.4%,取得了明显的冶金效果。 The resulfurization and the change of sulphur content in production of electrical steel is analyzed.The targeted measures have been taken,such as increase the loaded quantity of liquid iron,quartz sand replaces the composite slagging agent in the converter and RH desulfurization to decrease the sulphur content of the steel.The result shows,after the measures have been taken,the finished product ratio of electrical steel increase a lot.The ratio of sulfur content of finished product no more than ...
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...
电工钢柱状晶热、冷轧时晶界作用分析
利用XRD和EBSD研究了长轴分别平行于轧向(RD)、横向(TD)和轧面法向(ND)的柱状晶样品在热轧、冷轧及退火过程中的组织、织构演变规律,并分别从几何诱导和取向诱导两个方面分析了晶界的交互作用.结果表明,热轧时由表面摩擦剪切作用引起的组织和织构梯度直接影响并遗传给后续冷轧及退火样品.热轧后,不同样品的初始晶粒形状各向异性差异消失,形成相同的各向异性晶界组织,但晶体学各向异性发生改变,导致随后冷轧、退火组织及织构的变化均不同于直接冷轧的柱状晶样品.研究中特别关注了对磁性能有利的{100}取向区域与晶界的关系. Columnar grains show their special characteristics of morphological and crystallographic anisotropies, and thus markedly influence the microstructure and texture evolution during rolling and annealing process in electrical steel. The rolling and annealing microstructure and texture of three columnar grained samples with the long axes arranged along different directions were investigated by means of XRD and EBSD techniques, and the effects of columnar grain boundaries were analyzed from the view ...
D21硅钢芯片冲压工艺分析及模具设计
变压器D21硅钢铁芯片采用冲压工艺生产。首先对其工艺进行了分析,确定了冲压方案。对产品进行了排样设计,计算了冲压力,确定了压力中心。然后,设计了单工序落料模具,完成了模具装配图。 D21 silicon steel chips for transformer are produced by stamping.First,its stamping process was analyzed and the scheme of the stamping process was determined.The product layout was designed,the punching pressure was calculated,the pressure center was determined.Then,the blanking die with single procedure was designed,the die assembly drawing was completed.
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...
