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...
RH精炼工艺对无取向硅钢MgO·Al_2O_3夹杂物演变影响及控制
基于BOF→RH→CSP生产工艺,研究了RH精炼过程钢中夹杂物类型演变及MgO·Al2O3夹杂物形成规律,同时对MgO·Al2O3夹杂物的形成条件进行了热力学计算,借助CFD数值模拟软件研究了RH精炼过程卷渣行为。研究发现,RH精炼过程20和30 min时,w([MgO])/w([Al2O3])为0.005~0.020,未发现MgO·Al2O3夹杂物;RH出站后夹杂物w([MgO])/w([Al2O3])为0.3~0.5,且RH精炼结束后MgO·Al2O3夹杂物占夹杂物总量的58.4%;另外,RH精炼过程钢液表面速度CFD模拟结果为0.57 m/s,大于临界卷渣速度0.45 m/s,且顶渣成分与夹杂物成分相近,存在卷渣现象。热力学计算表明,钢液与炉渣平衡时钢中w([Al])为0.31%~0.37%,w([Mg])为0.00024%~0.00028%,在MgO·Al2O3生成区域之内。减少RH处理过程卷渣,浇铸过程下渣及控制顶渣和包衬相中MgO质量分数可抑制MgO·Al2O3夹杂物形成。 Based on the practical production of non-oriented silicon steel, the evolution of inclusion type and the formation of MgO·Al2O3inclusion were analyzed in the process of BOF→RH→CSP. The thermodynamic conditions for forming MgO·Al2O3inclusion were discussed and the behavior of slag entrapment of molten steel was also simulated by CFD software during RH refining. The results showed that the value of w([MgO])/w([Al2O3]) was in the range of 0.005-0.020 and no MgO · Al2O3 inclusion was observed at 20 ...
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...
不同牌号无取向硅钢夹杂物定性定量分析
无取向硅钢中夹杂物的存在会抑止晶粒生长,使基体的均匀连续性中断,其在钢中的形态、含量及分布情况都不同程度影响着硅钢的性能,尤其是对磁性能起关键的作用。因此,全尺度分布考察夹杂物对无取向硅钢夹杂物的研究极为重要。本实验确定了适用于不同牌号无取向硅钢夹杂物全尺度分布的分析方法:样品制备—小样电解—过滤喷金—根据不同牌号的要求选择合适的放大倍率扫描观测—夹杂物颗粒的分类统计。通过统计的结果,结合电解的失重量可以得到不同尺度的体积分布数据。实验分析了不同牌号和工艺无取向硅钢夹杂物的种类、形貌、大小和尺度分布,并初步考查了夹杂物与磁性能的关系,对无取向硅钢的工艺研究具有一定参考价值。 Inclusions in non-oriented silica steel could inhibit the growth of grain and cause discontinuity of micro-structure.The configuration,content and size distribution of inclusion have different effects on the performance of silica steel,especially significant on the magnetic property.Therefore,it is very useful to completely characterize inclusions with full size distribution in silica steel.In our research,full size analysis method for inclusion in silica steel had been established as follows: s...
余热利用系统在硅钢连续退火机组中的应用
介绍了烟气余热利用系统的工艺流程及控制思想,结合该系统在钢厂硅钢连续退火机组中的应用实践,估算出烟气余热利用系统每年可节约蒸汽5 040 t,经济效益良好,同时分析了该系统存在的问题及对策。 Introduced a method about the process and control of the application of waste heat system, which had been used into a silicon steel continuous annealing line and profiting a good economic benefit by saving a large number of steam every year, which has been estimated about 5 040 tons, and analyzed the problems and solutions existed in this system.
钙合金处理硅钢中的夹杂物及晶粒成长变化
采用RH精炼添加钙合金方式对硅钢进行钙处理,结果表明,钙合金添加量为0.67、1.00和1.67 kg/t钢时,钢中Ca含量分别为0、2×10-6和4×10-(6质量分数);随着钙合金添加量的增加,钢中夹杂物粒度逐渐由0～2μm向2～4μm、4～6μm偏移;不同钙处理条件下,钢中均存在粒径小于1μm和粒径为1～5μm的MnS、CuxS夹杂物,后者或单独存在,或与AlN、CaS夹杂复合;钢中粒径为5～10μm的夹杂物基本以Ca的氧化物和硫化物为主。与未经钙处理的炉次相比,钙合金添加量为0.67、1.00和1.67 kg/t钢时,粒径小于1.0μm的夹杂物减少幅度分别为68.06%、87.50%和94.94%。钙合金添加量为1.67 kg/t钢时,可以去除钢中绝大部分的微细夹杂物。 In order to improve the properties of final silicon steels,the calcium treatment was adopted by adding Ca alloys into the liquid steel during the RH refining process.Results show that when the addition of Ca alloys is 0.67 kg/t,1.00 kg/t and 1.67 kg/t,the corresponding Ca content in silicon steels is 0,2 × 10-6 and 4 × 10-6 respectively.With the increase of Ca alloy addition,the particle sizes of inclusions in steels become 2～4 μm and 4～6 μm,from 0～2 μm.Under different calcium treatments,there e...
表面机械研磨/异步轧制无取向硅钢薄带的渗硅行为
对w(Si)=3%无取向硅钢进行表面机械研磨处理(SMAT)和异步轧制(CSR),获得表面纳米结构,再进行550～650℃、4 h固体粉末渗硅处理,用透射电镜(TEM)、扫描电镜(SEM)和X射线衍射仪(XRD)研究表层组织演变。结果表明:经过SMAT后,w(Si)=3%无取向硅钢表面形成了等轴状、取向呈随机分布的、晶粒尺寸为10 nm的纳米晶组织;异步轧制后,表面纳米晶组织保持不变;550～650℃、4 h渗硅处理后,SMAT+CSR样品表面形成化合物层,其厚度随着温度的升高由17μm增加到52μm;化合物层由Fe3Si和FeSi相组成. Nanostructured surface layer was fabricated on a 3%(mass fraction) non-grain oriented silicon steel by means of surface mechanical attrition treatment(SMAT) and cross-shear rolling(CSR),and then a solid powder siliconizing treatment was carried out for the SMAT+CSR sample at 550~650 ℃ for 4 h.The microstructural evolution was examined by using transmission electron microscopy(TEM),scanning electron microscopy(SEM) and X-ray diffraction(XRD).Experimental results show that: equiaxed nanocrystallin...
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...
