钢厂
无取向电工钢深脱硫试验
为满足用户对无取向电工钢中硫含量的要求,采用CaO-CaF2复合渣系为脱硫剂,利用RH投入法对无取向电工钢进行深脱硫试验。试验结果表明,RH精炼渣成分控制在w CaO43%~51%、w Al2O325%~31%、w MgO4%~6%、w SiO29%~12%、w(FeO+MnO)3%~6%,在脱硫剂加入量为6~8 kg/t时,钢中平均硫含量从32×10-6降低到18×10-6,RH平均脱硫率为43.3%,最高达47.1%。利用KTH模型计算精炼终渣平均硫容量为0.003 1,RH精炼结束时渣-钢间实际平均硫分配比从14增加到52。 In order to satisfy the requirements of consumers on sulfur content in non-oriented electrical steel,taking( CaO-CaF 2) based flux as desulfurizer,industrial experiments on deep desulphurization of non-oriented electrical steel were carried out during RH process. The results show that as the compositions of refining slag are appropriately controlled with w CaO of 43% ~ 51%,w Al2O3 of 25% ~ 31%,w MgO of 4% ~ 6%,w SiO2 of 9% ~ 12%,and w( FeO + MnO) of 3% ~ 6%,and the desulfurizer added are at 6 ~ ...
微量Sn对0.4%Si无取向硅钢组织和磁性能的影响
结合实际生产0.4%Si无取向硅钢,统计了不含Sn和0.025%Sn无取向硅钢的磁性能变化,利用金相显微镜、X射线衍射仪观察分析不同成分下试样的显微组织和微观织构。试验结果表明:Sn元素可以显著降低无取向硅钢的晶粒尺寸,0.025%Sn试样的平均晶粒尺寸比不含Sn减小28.4%;加入Sn元素后抑制了无取向硅钢中不利于磁性能的{111}面织构组分强度,提高了对磁性能有利的{100}面织构组分强度,0.025%Sn与不含Sn相比磁感均值从1.756 T提升至1.768 T,铁损均值从5.476 W/kg降低至5.204 W/kg,明显改善了无取向硅钢磁性能。 In this paper combined with the actual production of 0.4% Si non oriented silicon steel, the magnetic properties of non oriented silicon steel without Sn and 0.025% Sn were counted. The microstructure and microtexture of samples with different compositions were observed and analyzed by metallographic microscope and X-ray diffraction. The results show that: Sn can significantly reduce the grain size of non oriented silicon steel, and the average grain size of 0.025% Sn sample is 28.4% smaller tha...
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...
0.3 mm厚的高强无取向电工钢的退火组织与性能
借助光学显微镜、扫描电镜、交流磁性能测量仪和万能拉伸试验机研究了0.3 mm厚高强无取向电工钢冷轧板在780、820、860和900℃退火保温2 min后的组织、织构和性能。结果表明:在退火温度范围内,试验钢均发生了完全再结晶,得到等轴状的铁素体晶粒;随着退火温度的升高,平均晶粒尺寸从9.2μm增长到41.3μm,工频铁损和400 Hz高频铁损均先大幅减小后趋于平缓,磁感应强度先升高后降低。在820℃退火时,铁损P1.5/50=5.51 W/kg,P1.0/400=33.22 W/kg均处于较低值,磁感应强度B5000最大,为1.649 T。试验钢的屈服强度和抗拉强度均随退火温度的升高而降低,780℃退火时屈服强度为496 MPa, 900℃退火时降低至407 MPa。综合磁性能和力学性能考虑,试验钢的最佳退火温度是820℃。 Microstructure, texture and properties of 0.3 mm thick high strength non-oriented electrical steel cold rolled sheet annealed at 780 ℃, 820 ℃, 860 ℃ and 900 ℃ for 2 min were studied by means of optical microscope, scanning electron microscopy, AC magnetic property tester and universal tensile testing machine. The results show that in the annealing temperature range, complete recrystallization of the experimental steel occurs and equiaxed ferrite grains are obtained. With the increase of annealin...
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...
氢氧化镁煅烧制备硅钢级氧化镁的研究
以青海盐湖氯化镁为初级原料,采用喷雾热解法制备原料氧化镁。原料氧化镁通过水化制备氢氧化镁。将氢氧化镁过滤、洗涤、烘干、粉碎、煅烧,制备硅钢级氧化镁。本文重点考察煅烧温度、煅烧时间、料层厚度等因素对氧化镁水化率的影响,采用均匀实验设计和DPS数据处理,确定最优煅烧实验条件为:煅烧温度1250℃,煅烧保温时间4小时,料层厚度0.5cm。在此条件下得到的硅钢级氧化镁完全满足硅钢及氧化镁的行业标准。 The magnesium oxide is prepared by Spray pyrolysis process,which magnesium chloride from Qinghai Salt Lake is used as primary raw material,and hydrated to magnesium hydroxide,then obtained silicon steel magnesia through filtering,washing,drying,crushing and calcinations.In this paper,influences of some factors on magnesia hydration rate are studied,such as calcination temperature,calcination time and material thickness.After average experimental design and DPS data processing,optimal calcination...
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...
薄带连铸取向硅钢的热轧孪生行为
薄带连铸流程下取向硅钢粗大λ晶粒(〈100〉//ND,normal direction)的“遗传”会导致磁性能恶化.为解决这一问题,针对取向硅钢的热轧孪生行为开展研究,结果表明:凝固组织粗大的取向硅钢在650℃热轧时可产生大量{112}〈111〉形变孪晶,这与具有高层错能的硅钢在较高温度下难以孪生变形的传统认知不同.热轧过程中复杂的应力状态降低了变形孪晶的取向依赖性,由于具有更高的储存能,孪晶界/孪晶界及孪晶界/晶界交叉点成为再结晶形核的优先位置,大大提高了常化过程中的再结晶率,受沿孪晶界应变分布及孪晶间距离的限制,沿孪晶界形核的再结晶晶粒通常呈“饼状”,最终形成以细小且取向漫散的再结晶晶粒为主的常化组织,消除了初始凝固组织中有害的粗大λ晶粒. In strip casting grain-oriented silicon steels, the inheritance of coarse λ grains(〈100〉//ND, normal direction) can deteriorate their magnetic properties. To solve the problem, twinning behaviors in strip casting grain-oriented silicon steels during hot rolling were investigated in this work. It is found that after rolling at 650 ℃, a number of {112}〈111〉deformation twins are formed in the coarse solidification microstructure of the steels, in contrast to the well-accepted view that it is diffic...
薄板坯连铸连轧生产中低牌号无取向硅钢的实践
本文中简要介绍了武汉钢铁有限公司采用薄板坯连铸连轧CSP(compact strip production, CSP)工艺生产中低牌号无取向硅钢的实践情况.CSP工艺生产的硅钢具有成品磁性均匀、板形好的优势,但是在利用该技术生产中低牌号无取向硅钢时,常存在成品板表面瓦楞状缺陷严重、连铸生产效率低等问题.通过优化炼钢成分、热轧等相关工艺,可消除热轧板厚度方向中心的粗大形变组织,从源头上避免了粗大{100}<011>纤维组织的出现,消除了瓦楞状缺陷;通过提升冶炼效率和控制钢中夹杂物总量,可优化隧道炉的加热温度与在炉时间,大幅度提升了连铸生产效率,实现了中低牌号无取向硅钢的批量稳定制造,使CSP产线成为中低牌号无取向硅钢热轧板原料的主要供给生产线.如何进一步提升钢水纯洁度、提高连铸生产效率、降低生产成本,以及挖掘该产线生产薄带钢的技术优点,是未来工作的重点. This paper briefly introduces the practice of producing medium and low grade non oriented silicon steel(NGO) with CSP(compact strip production, CSP)technology in Wuhan Iron and Steel Co., Ltd.. This technology has the inherent advantages of uniform magnetic properties and good shape for silicon steel finished strip. However, in the actual production process, there are serious corrugated defects on the surface of silicon steel finished strip, and production efficiency of continuous casting is low...
冷轧工艺对取向硅钢初次再结晶织构的影响
研究了取向硅钢制备过程中常见的两种冷轧工艺,主要研究了一阶段冷轧与两阶段冷轧+中间退火工艺对初次再结晶组织及织构的影响.结果表明:采用两阶段冷轧+中间退火工艺制备以Cu2S为主抑制剂的取向硅钢,其初次再结晶平均晶粒尺寸为18.1μm,高斯晶粒的体积分数为0.6%,迁移性强的重位点阵晶界(Σ5+Σ9)和高能晶界(20°~45°取向偏差角)所占比例分别为1.8%和50.4%.与一阶段冷轧工艺相比,其初次再结晶晶粒较细,且高斯晶核与特征晶界所占的比例较高,有利于高斯晶粒发生二次再结晶. Two common cold-rolling processes of grain oriented silicon steel and the effects of the single stage cold rolling and tw o-stage cold rolling w ith intermediate annealing processes on the primary recrystallization microstructure and texture w ere investigated. The results revealed that for the grain oriented silicon steel prepared under the tw o-stage cold rolling process w ith intermediate annealing w ith Cu 2 S as the main inhibitor,the average grain size of the primary recrystallization micr...

