钢厂
电工钢热压缩时动、静态再结晶组织及取向分析
采用热模拟方法及EBSD技术,研究Fe-3 wt%Si电工钢在不同温度下组织的动、静态再结晶及晶粒取向特征,特别是少量奥氏体对铁素体动、静态再结晶组织及取向的影响。结果表明,不同温度形变的组织主要分三类:形变长条铁素体、珠光体和等轴细小铁素体。长条形变铁素体内发生动态回复或连续式的动态再结晶,奥氏体周围的铁素体动态再结晶加速,部分以传统的不连续方式动态再结晶。铁素体、奥氏体都可发生静态再结晶。奥氏体的静态再结晶在1050℃以上明显,铁素体的静态再结晶随温度的升高逐渐进行,最显著的再结晶发生在1050℃。不同温度形变的样品,其形变晶粒取向主要以<111>和<100>为主,小等轴铁素体晶粒除与大形变铁素体取向相近外,出现了<110>取向及其它取向。 Static and dynamic recrystallization and grain orientations in a hot-compressed Fe-3 wt% Si electrical steels were studied at different temperatures using Gleeble simulator and EBSD technique,particularly focusing on the effect of small amount of austenite on ferritic microstructure and orientations.The results show that microstructure of the compressed steel,depending on deformation temperature,consisted of elongated and deformed ferrite,pearlite and fine equal-axed ferrite.The elongated ferrit...
钇元素对6.5%Si无取向硅钢组织、高温拉伸及断裂机制的影响
通过微观组织表征、高温拉伸和断口形貌分析,研究了钇(Y)元素对6.5%Si无取向硅钢组织、高温拉伸及断裂机制的影响。研究结果表明,添加Y元素可以在钢液中形成YS和YP的复合析出。YS和YP可以充当异质形核基底,提高形核率,细化凝固组织。热轧组织不均匀,由表层至芯部分别形成等轴晶、等轴晶/拉长晶和拉长晶的混合组织。退火后,热轧变形组织转变为等轴晶,含Y实验钢的退火组织得到明显细化。500℃时效处理后,含Y实验钢具备较低的有序度,300℃的拉伸断口呈现韧性断裂特征,断后伸长率达到20.2%。相反,无Y实验钢发生脆性断裂,断后伸长率仅为2.1%。研究结果证实,Y元素可以通过组织细化和降低有序度提高6.5%Si无取向硅钢的中温塑性。 The effects of yttrium(Y)on microstructure,elevated-temperature tensile properties and fracture mechanism of 6.5% Si non-oriented electrical steel were investigated by means of microstructure characterization,high-temperature tensile test and fracture analysis.The results showed that the doping of Y introduced composite Y-rich precipitates(YS/YP)in the melt.YS and YP precipitates were qualified for heterogeneous nucleation agents,which thus raised the nucleation rate and refined the solidificati...
取向硅钢常化水冷温度模型及控制方法研究
取向硅钢常化工序主要采用现场实测带钢温度的方式测定冷却速率,并通过稳定冷却水温、调整冷却水量及喷梁运行数量等方式保证合理的冷却速率,给常化工艺设计和生产带来诸多不便。通过对常化工艺水冷过程带钢的传热分析求解,在建立带钢水冷温度模型的基础上,研究了不同冷却工艺参数对带钢温度及冷却速率的影响规律以及冷却工艺的交互作用结果。结果表明:模型计算结果能够较好地反映取向硅钢在常化水冷过程中的温度及冷却速率的变化,其计算误差为0.80%~4.11%;在特定取向硅钢厚度规格和常化工艺下,随着常化冷却水量及有效冷却长度的增加,带钢水冷温度及冷却速率与呈非线性变化;常化水冷工艺主要通过调控带钢与冷却水之间热交换量和交换时间实现对带钢温度的控制,实际生产中需综合考虑机组速度、冷却水量及有效冷却长度之间的交互作用,选定喷梁投入数量和冷却水量以获得稳定的冷却速率。 The cooling rate of normalization process mainly determined by measuring the grain oriented silicon steel strip temperature on site, and ensures the cooling rate by stabilizing the cooling water temperature, adjusting the cooling water volume and the operation quantity of spray beam, which brings inconvenience to the normalization process design and production. Based on the heat transfer of strip in the water cooling section of normalization process, the water cooling temperature model for the n...
取向电工钢加工过程中第二相粒子的析出行为
利用场发射扫描电镜观察了以MnS为主要抑制剂的普通取向电工钢加工过程中第二相粒子的分布状态,统计了粒子面密度、平均尺寸以及相应的尺寸分布.结果显示,热轧加工造成了大量第二相粒子弥散、细小地析出,同时基体仍保持过饱和状态.冷轧变形会造成第二相粒子的回溶行为,而基体的过饱和状态会减弱回溶现象.中间退火与脱碳退火过程中会同时存在新粒子的形核及已析出粒子的粗化两个过程,而在最终二次再结晶升温阶段则以第二相粒子明显粗化为主. The distribution of second phase particles in conventional grain-oriented electrical steels during manufacturing processes with MnS as inhibitors was observed by field emission scanning electron microscopy,while the areal particle density,the average particle size and the corresponding size distribution were statistically determined.It is indicated that hot rolling leads to dispersive precipitation of a large amount of fine second phase particles and the matrix keeps a supersaturated state furth...
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...
凝固速率对定向凝固50W600无取向硅钢固液界面稳定性和枝晶间距的影响
采用ZMLMC超高梯度定向凝固装置,研究了5种凝固速率(10、35、80、150和450μm/s)对定向凝固50W600无取向硅钢的固液界面稳定性转变规律和一次、二次枝晶间距的影响。研究结果表明,在特定的温度梯度下,随着凝固速率的增加,定向凝固的固液界面由胞状晶转变为胞状枝晶,再转变为细小的树枝晶。随着凝固速率的增加,定向凝固组织的枝晶形貌逐渐细化,一次和二次枝晶间距逐渐减小,且与冷却速率之间都符合指数关系:λ1=151.73×(G L·R)-0.31,λ2=22.07×(G L·R)-0.44。当冷却速率达到4.275℃/s时,一次、二次枝晶间距分别为112μm、14.1μm。 Under the conditions of certain temperature gradient and different solidification rate,the directional solidification experiment of non-oriented electrical steel 50W600 was carried out.The microstructure of 50W600 steel was also analyzed in different solidification rate.The result shows that the solid/liquid interface of the steel undergoes an evolution from cellular,cellular dendrite and finally to fine dendrite morphologies.The dendrite refines gradually and the distance between dendrites decr...
硅钢连续退火生产线设备改造
针对硅钢连续生产线设备存在的故障、隐患以及精度等影响产品质量的问题进行分析及改造,实现保证生产线设备稳定运行、提高设备精度及硅钢产品质量的目的。 This paper analyzes and transforms the electrical equipment failures, risks existed in slicon continuous production line, and the effect of accuracy to product quality, in order to ensure stable operation of equipment in production line and improve the accuracy of device, quality of silicon.
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...
热处理工艺对含Mn高硅钢热轧带的组织及硬度的影响
研究了热处理工艺(退火温度、保温时间、冷却方式)对含Mn的Fe-6.5wt%Si高硅钢热轧带的显微组织及硬度的影响。结果表明,退火温度对Fe-6.5wt%Si合金的组织和显微硬度均有较大影响,随退火温度升高,平均晶粒尺寸和显微硬度均明显增大。小于1 h退火时,晶粒长大缓慢,而长时间(>1 h)退火时,一些次表层晶粒将发生异常长大。水冷组织比空冷组织略细小,但水冷显著降低了显微硬度。Mn含量提高能抑制850℃退火时晶粒的长大,并且促进退火后高硅钢的软化。 The influences of heat treatment process(annealing temperature,heating time,cooling methods) on the microstructure and microhardness of Fe-6.5wt%Si high silicon steel containing manganese for hot rolled strip were studied.The results show that the annealing temperature has a great effect on the microstructure and microhardness of Fe-6.5wt%Si alloy,and as the annealing temperature increases,the average grain sizes and microhardness will significantly increase.When annealing time for less than 1 h...
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 ...

