钢厂
硅钢级氧化镁反应行为的研究
利用DSC、XRD,结合热焓分析对硅钢级氧化镁和二氧化硅的固相反应行为进行了研究。比较了不同二氧化硅原料及混合方法对硅钢级氧化镁反应性的影响,找到了一种更为有效的硅钢级氧化镁反应性的评估方法,克服了传统柠檬酸活性法在比较不同厂家生产的氧化镁的反应性上的局限性。进一步研究了Na2B4O7添加剂、TiO2添加剂对氧化镁和二氧化硅反应行为的影响,结果表明,Na2B4O7添加剂含量的增加对反应有利,而TiO2添加剂对反应有阻碍作用。 The solid-state reaction behavior between silicon-steel grade MgO and SiO2 was investigated by DSC and XRD combined with enthalpimetric analysis.The influence of different kinds of SiO2 and different preparation methods were studied and a specifical measurement that is more reliable was proposed to evaluate reactivity of silicon steel grade MgO.It overcomes the limitation of the traditional citric acid activity（CAA） method,which can not be used to evaluate the reactivity of...
初次再结晶退火工艺对3%Si取向硅钢组织和织构的影响
试验研究了0.3 mm取向硅钢冷轧板(/%:0.046C,3.07Si,0.09Mn,0.029P,0.004S,0.005A1)的退火温度(760~880℃7 min)和退火时间(820℃3~9 min)对该钢的晶粒尺寸,再结晶和织构的影响。结果表明,最佳初次再结晶退火工艺为820℃5 min,该钢的平均晶粒尺寸为14.20μm,完全再结晶率为92%,不利{111}<110>结构含量为3.16%,有利织构{111}<112>,{012}<001>和高斯织构含量分别0.40%,4.73%和2.46%。 The effect of annealing temperature(at 760 ~ 880 X.for 7 min) and time(at 820℃ for 3~9 min) on grain size,recrystallization rate and texture of 0.3 mm cold-rolled sheet of oriented silicon steel(/%:0.046C,3.07Si,0.09Mn,0.029P,0.004S,0.005Al) has been tested and studied.Results show that with optimum recrystallized annealing at 820℃ for 5 min,the silicon steel average grain size is 14.20 fun,the complete recrystaUization rate is 92%,the unfavourable-texture {111}< 110 > content in steel is ...
高Cu无取向电工钢的制备
运用EBSD和光学显微镜,研究了0.25%~0.45%Cu对无取向电工钢热轧板显微组织,成品板显微组织、织构和磁性能的影响。实验结果表明:卷取过程中Cu元素在热轧板表层的偏聚作用显著阻碍了热轧板表层再结晶晶粒长大,导致热轧板表层晶粒尺寸随着Cu含量增加而逐渐较小,但热轧板中间晶粒尺寸变化不大。同时发现Cu元素能够明显改善织构类型,使有利织构组分增加,不利织构组分减少,同时减弱织构强度。从实验结果可知0.35%Cu能够显著改善电工钢的磁性能,铁损P15/50最低达到4.1 W/kg,磁感B50最高值达到1.8 T。 Effects of high content Cu on microstructure of hot rolled plates and microstructure,texture and magnetic properties of annealed finish product plates of non-oriented electrical steel were examined by means of EBSD technique and optical microscope. The results show that surface segregation of Cu significantly hindered recrystallized grain growth of surface layer in hot rolled plate during the coiling,as a result,the surface grain sizes of the hot-rohed plates decrease with the increase of Cu con...
含铜无取向电工钢中析出相及其析出机理
研究了含铜低碳低硅无取向电工钢中的析出相及其析出机理.由能谱(EDS)及选区电子衍射(SAED)分析可知,铁素体基体上存在的大量弥散分布的等轴状析出相为类B2结构的铜.这些铜析出相的析出机理可以是一般析出、位错析出、台阶机理相间析出和弓出机理相间析出:一般析出在550、650和750℃三个等温温度均可发生;位错析出只发生在较低的等温温度(550℃),此时析出相呈特殊的平行短列状;台阶机理相间析出也可在上述三个等温温度下发生,但650℃等温时最有利于台阶机理相间析出,此时析出相平直列状分布;弓出机理相间析出只发生在较高的等温温度(750℃),析出相弯曲列状分布. Precipitates in low-carbon low-silicon non-oriented electrical steel containing Cu were studied and the precipitation mechanism was analyzed by means of energy dispersive spectrometry(EDS) and selected area electron diffraction(SAED).It is found that the equiaxed precipitates of Cu with B2-like structure distribute dispersively in the non-oriented electrical steel.The precipitation mechanism involves general precipitation,dislocation precipitation,interphase precipitations formed by the ledge me...
电脉冲对取向硅钢凝固组织的影响
对熔融态钢液进行处理,研究了电脉冲对于取向硅钢凝固组织的影响作用,利用正交试验法研究了脉冲电容、频率、处理时间和电压等脉冲参数的作用效果。结果表明:电脉冲对钢锭晶粒组织具有明显的细化作用,凝固组织的等轴晶比例大幅上升,影响等轴晶比例的最显著性因素为脉冲频率,最优正交试验参数为电容1 200μF,脉冲频率1 Hz,处理时间5 s,脉冲电压800 V。随着输入能量的增大等轴晶率先增大后减小,脉冲输入能量为某值时,等轴晶率最大,利用经典形核理论和热力学对这一现象进行了解释。 The influence of electric pulse on the solidification structure of oriented silicon steel was investigated by applying electric pulse in molten steel.The affection due to different electric pulse parameters such as electric capacity,frequency,applied time and voltage was studied by orthogonal design test.The result showed that solidification structure of oriented silicon steel could be improved by the electric pulse,and the equiaxed crystal ratio increased obviously.The most influential paramete...
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,...
一次再结晶法取向硅钢超薄带的冷轧塑性变形行为
以市场上购买的取向硅钢成品板为原料，经不同压下率冷轧至0.23～0.08 mm不等。借助X射线衍射仪(XRD)检测了冷轧后样品中的织构组分及其含量，利用电子背散射技术(EBSD)测量了试样的取向因子分布情况。观察了孪晶的形貌与晶体学特征，分析了硅钢超薄带的塑性变形行为。结果发现，在平面压缩应力下，{112}<111>滑移系的取向因子较大。随冷轧压下率的增加，Goss织构的含量逐渐减少，{212}<141>织构组分的含量先增加后减少，{111}<112>织构组分的含量逐渐增加，织构组分以{110}<001>→{212}<141>→{111}<112>顺序演变。冷轧后样品中出现了孪晶，其晶体取向为{001}<110>,冷轧过程中孪晶取向没有发生变化。 The commercial finished oriented silicon steel plate as the raw material were rolled to 0.23-0.08 mm. With the X-ray diffractometer(XRD), the texture components and their volume fractions in the cold-rolled samples were detected. And the orientation factor distribution of the cross-section of the samples was measured by the electron backscattering technique(EBSD). The morphology and crystallographic characteristics of twins were observed, and the plastic deformation behaviors of the ultra-thin o...
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...
