钢厂
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...
新型无取向电工钢在退火过程中组织和织构取向的演变
通过金相分析和电子背散射衍射技术研究了一种新型含铜无取向电工钢在950℃退火不同时间(3～180s)空冷后的组织和织构取向的演变。结果表明:该钢在退火3s时的主要织构为α和γ线织构,{100}<110>织构最强;退火20s时织构以<111><112>、{111}<110>、{112}<110>、高斯织构和立方织构为主,随着退火时间的延长,高斯织构和立方织构强度呈减弱趋势;合理控制保温时间有利于提高{100}、{110}面织构的占有率。 Evolution of microstructure and texture oriented of a new non-oriented electrical steel during annealing at 950℃for different times(3-180) s and air cooling was studied by metallography and electron back-scattering diffraction analysis.The results show that after annealing for 3 s most of the texture oriented alongα-fibre andγ-fibre,the intensity of {100}〈110〉was the strongest.{111}〈112〉,{111}〈110〉,{112}〈110〉,Gauss texture and cube texture were the main texture after annealing for 20 s,with the ...
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 ...
正火对双辊薄带连铸5.28%Si-1.11%Al无取向高硅钢磁性能的影响
采用双辊薄带连铸工艺试制了2.6 mm厚5.28%Si-1.11%Al高硅钢薄带,对比了1050℃×5 min正火及不正火铸带280℃冷轧至0.5 mm后,再经900～1100℃退火的磁性能。结果表明,高硅钢铸带显微组织为等轴晶组织,正火后铸带边部晶粒长大,中心层晶粒变化较小。成品中析出物主要为较粗大的AlN和AlN+MnS复合析出物,尺寸为0.5～2.5μm。与不正火试样相比,正火试样成品铁损大幅降低,磁感小幅下降;随退火温度的升高,两种工艺下铁损和磁感都是先降低后升高,在1050℃出现最低值。 2.6 mm thickness 5.28% Si-1.11% Al non-oriented high silicon steel was produced by twin roll thin strip casting.Magnetic property of the strip un-normalized and normalized at 1050 ℃×5 min was contrasted after cold rolled to 0.5 mm at 280 ℃ and 900-1100 ℃ final annealing.The results show that microstructure of the strip is equiaxed crystal.The surface grain is coarsened and the center layer grain has little change of the normalized strip.The main precipitates are AlN and MnS+AlN with 0.5-2.5 μm s...
异步轧制硅钢的表面纳米化及轧制参数的影响
对硅钢板材分别进行异步和同步轧制,研究了轧制参数包括速比、压下量和道次对板材表面显微组织的演变的作用.结果表明,异步轧制硅钢板材表面形成了晶粒尺寸为10~50 nm,取向接近随机分布的纳米晶,而同步轧制板材的表面只形成了位错胞,证明异步轧制可以诱发表面纳米化.异步轧制板材表面纳米晶的形成过程为:在剪切力的反复作用下,高密度位错形成、滑移、湮灭和重组形成亚微米尺度的亚微晶/位错胞.随着压下量和轧制道次增加,高密度位错重复以上过程使晶粒尺寸减小、取向差增大,最终形成取向接近随机分布的纳米晶组织.大压下量和多道次是异步轧制诱发板材表面纳米化的关键,而速比的增加可以加快纳米化进程. Surface nanocrystallization(SNC) can effectively enhance the surface and global properties of the metallic materials,such as microhardness,intensity,fatigue,wear and corrosion resistances,therefore provides more promising practical industrial applicability.Up to now,several SNC treatment methods were developed based either on the principles of ball impactions or friction sliding,however,difficulty still exists for the surface treatment of large-dimensional samples with high efficiency.Recently,m...
RH精炼喂CaSi线去除无取向硅钢中的非金属夹杂物
结合工业化生产的无取向硅钢,进行了RH精炼喂CaSi线去除钢中的非金属夹杂物试验研究。针对不同的钙处理条件,分析了CaS夹杂生成热力学,观察了夹杂物的形貌和尺寸分布,确定了夹杂物的类型、数量,探讨了钙处理后钢中夹杂物的变化规律。结果表明,本试验条件下,钙处理可以有效抑制MnS、AlN夹杂物的生成,有效促进钢中微细夹杂物的聚合、上浮、去除,钢质纯净度明显提高。经过合适的钙处理后,钢中的夹杂物以独立存在的CaO为主,同时有少量含CaO、SiO2、MgO的复合夹杂,没有发现CaS夹杂存在。这部分夹杂物的尺寸集中分布在2～20μm,数量约为1.8×105个/mm3。 Experimental study on removal of non-metallic inclusions in non-oriented silicon steel obtained from industrial production by CaSi wire feeding during RH refining process was carried out.The thermodynamics of CaS inclusion formation was analyzed,the morphology and the size distribution of inclusions were observed,and the numbers and types of inclusions were also determined for the steel specimens treated under different calcium treatment conditions.Furthermore,the variation of inclusion characte...
冷轧无取向硅钢横向厚差控制
冷轧中中低牌号的无取向硅钢多采用万能凸度轧机(Universal crown mill,UCM)生产,其板形好坏受制于UCM轧机板形调节手段的协调使用。为掌握UCM轧机的板形控制特点,建立基于二维变厚度有限元的辊系弹性变形和基于三维差分的轧件塑性变形的六辊轧机耦合模型,对UCM轧机的板形调控性能进行详尽的分析,包括工作辊和中间辊弯辊、中间辊窜辊的调控功效、辊间接触压力分布等。在此基础上,提出可用指导生产的板形控制策略,指出UCM轧机在横向厚差控制方面的不足。针对工业生产中UCM轧机轧制无取向硅钢横向厚差大的问题,在大量仿真计算的基础上,开发具有高次曲线函数的边部变凸度(Edge variable crown,EVC)的工作辊。采用该工作辊后,各种品种的无取向硅钢的横向厚差不大于10μm的百分比由24%提高到99%,横向厚差的均值小于6μm,远小于之前的13μm。 Medium-low grade non-oriented silicon steel is rolled often by universal crown mill(UCM) during cold rolling.Its shape quality is dependent on the coordinated control of several shape adjustment devices of UCM.In order to understand the shape control characteristics of UCM,coupling model of six-high rolling mill,based on two-dimensional varying thickness finite element rolls elastic deformation model and three-dimensional finite difference strip plastic deformation model,is setup for the detaile...
低温高磁感取向硅钢常化工艺中间冷却制度的研究
借助电子背散射(EBSD)技术对AlN为主抑制剂的Hi-B取向硅钢常化工艺的中间冷却制度进行了研究。结果表明:常化后试样均发生了完全再结晶,在60℃/s冷速下组织最均匀;在合适的冷却制度下常化板表层保留了强的Goss织构,它深入到1/4厚度处,并且形成对Goss织构有利的强{554}<225>织构。 The intermediate cooling system of Hi-B oriented silicon steel with AlN main inhibitor in normalizing process was studied by means of electron back diffraction(EBSD) technique. The results show that:the specimens after normalizing are fully recrystallization, and the microstructure is most uniform under the intermediate cooling rate of 60℃/s; under suitable cooling system, normalized plate surface retains strong Goss texture, it penetrates into the 1/4 thickness of the plate and forming strong {...
低温取向硅钢热轧态组织及织构的研究
利用热模拟试验机、光学显微镜和X射线衍射仪对Fe-3.2%Si低温取向硅钢热轧工艺参数对组织及织构的影响进行了研究。结果表明,Fe-3.2%Si硅钢在1110℃粗轧、880℃终轧,轧后以10℃/s的速度冷却到550℃卷取,然后空冷到室温,热轧硅钢板沿板厚方向的显微组织不均匀性显著,对后续发展完善的二次再结晶有重要作用。无论是热轧板,常化板还是冷轧板,它们的织构集中分布在γ取向线上,γ取向线的织构除取向密度不同外,织构种类是一致的,这说明γ取向线上织构是有继承性的。从热轧到常化,织构取向密度显著减小,经二次冷轧后,织构密度又显著升高,可见,轧制变形有助于织构的形成并使织构强度升高。 The influence of hot-rolled process parameters on the microstructure and texture of Fe-3.2%Si low temperature hot rolled grain-oriented silicon steel were researched by hot simulation experiment machine,light microscope and X-ray diffractometer.The results show that,Fe-3.2%Si silicon steel is rolled by the technology with a temperature of rough rolling of1110℃,finish rolling of 880℃,coiling with the speed of 10℃ /s,and then cooled to room temperature with air.The microstructure of hot-rolled sil...
