钢厂
高强度无取向电工钢疲劳性能及断裂机制
测试了高强无取向电工钢的S-N曲线,并借助光学显微镜、扫描电子显微镜、透射电子显微镜分析了实验钢组织,疲劳断口形貌和位错结构。结果表明:室温条件下,频率为20Hz,应力比R为0.1,循环10~7周次时,实验钢的疲劳强度为360MPa,疲劳裂纹萌生于实验钢的次表面,裂纹萌生点附近有沿晶开裂现象,疲劳裂纹扩展区域有解理台阶与疲劳条纹,瞬间断裂区是韧性断裂,有大量韧窝。实验钢在循环应力作用下基体中产生了大量位错,并有驻留滑移带终止在晶界位置。 The S-N curve of a high strength non-oriented electrical steel was tested.The microstructure and fatigue fracture morphology and dislocation were analyzed by optical microscope,scanning electron microscope,transmission electron microscope.The results showed that:at room temperature and the frequency of 20 Hz and the stress ratio Rof 0.1,the fatigue strength of the experimental steel was 360 MPa when the cycle was 10~7 cycles.The fatigue crack initiation at the surface of the steel and the interg...
电工钢中柱状晶对热轧和退火时晶粒取向及组织的影响
利用EBSD技术研究了电工钢中长轴平行于轧向的柱状晶样品在热轧和退火过程中组织和取向的演变规律,并与长轴平行于板法向的样品的已有研究结果进行对比。结果表明,无论柱状晶按何种方向排列,只要表面存在剪切力,热轧后都可形成剪切织构,同时中心形成轧制织构,主要包括旋转立方织构和{112}<1-10>。柱状晶造成的影响主要体现在板中心层,长轴平行于轧向排列的样品热轧时形成的粗大旋转立方晶粒要到脱碳退火后才能完全消除,但破坏了正常的不同取向晶粒间的取向差分布及尺寸均匀性,导致二次再结晶不完全及磁性能降低。 The evolution of microstructure and grain orientation in an electrical steel containing columnar grains with its long axis being parallel to the rolling direction of sheet was studied during hot rolling and annealing by EBSD technique.The results are compared with those of samples containing columnar grains being parallel to normal direction of sheet reported in the reference [3].It was shown that,whether the long axis of columnar grains was arranged in RD or ND,shear textures can be formed in t...
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,...
电力变压器用高磁感取向硅钢的发展及应用
阐述了国内外高磁感取向硅钢的生产研究水平与发展趋势,包括通过提高高斯晶粒取向度、细化磁畴、涂覆张力涂层、减薄钢片厚度进一步降低铁损以及低温加热技术和短流程技术新工艺。分析高磁感取向硅钢在我国大型电力变压器上的应用情况,结果表明,发展更薄规格高磁感、低铁损、低磁致伸缩取向硅钢可为大型变压器的安全性、节能性及环保性提供有效保障。 The research progress and development trend of high magnetic induction grain-oriented silicon steel at home and abroad are summarized,including the technology of improving the Goss alignment,refining domain wall,adding stress coating,decreasing thickness of sheet,and the new technique of reducing heating temperature of casting slab and shortening operational.Moreover,the application of high magnetic induction grain-oriented silicon in power transformer is presented.Developing grain-oriented sili...
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...
热变形温度对3%SiCGO硅钢组织和织构的影响
通过对3%Si CGO硅钢进行恒变形速率、不同变形温度下的单道次压缩实验,结合Thermal-Calc软件,金相分析,SEM及EBSD技术,研究了取向硅钢热变形过程中组织和微观织构的变化规律。结果表明:实验钢是在双相区变形,变形后组织主要是铁素体和少量的珠光体。随变形温度的升高,晶粒由长条状变为等轴状,尺寸逐渐变大;CGO硅钢在热变形过程中立方{100}<001>取向是较为稳定存在的。随着变形温度的提高,{111}<110>等取向逐渐转向{110}<1 10>取向,且{110}<1 10>取向逐渐变得锋锐。 3% Si CGO silicon steel was studied at constant strain rate and different deformation temperatures by single-pass compression deformation experiments to reveal the evolution of microstructure and texture during thermal deformation in oriented silicon steel,and the Thermal-Calc software,metallurgical,SEM and EBSD technique was used in the experiment. The results show that experimental steel is deformed at the temperatures of two-phase zone. The microstructure of the deformed steel consists of fer...
普通冷轧取向硅钢中间完全脱碳退火工艺的确定
为了确定普通冷轧取向硅钢最优的中间完全脱碳退火工艺,在其一次冷轧后进行5种不同工艺的脱碳退火处理,借助扫描电镜及电子背散射衍射技术研究了不同工艺脱碳退火后的组织、织构和脱碳效果。结果表明:经5种工艺脱碳退火处理后,初次再结晶的平均晶粒尺寸均约为19μm,且不随退火温度和时间的变化而变化;经840℃×10min工艺退火后的晶粒最均匀,高斯织构位向更准确,高斯织构面积分数最多,为3.1%,可将碳脱至0.003 5%。 In order to determine the optimal intermediate complete decarburizing annealing processes for common grain-oriented(CGO)silicon steel,five kinds of intermediate decarburizing annealing processes were conducted,the microstructure,texture and decarbonization after different decarburizing annealing processes were studied by scanning electron microscopy and electro back-scattered diffraction(EBSD)technology.The results show that the average grains sizes of primary recrystallization were about 19μm a...
