钢厂
薄板坯连铸连轧流程试制含钒钛取向硅钢中氮化物析出相
通过热力学计算与模拟试验研究了含钒钛取向硅钢中氮化物析出相的析出规律与析出行为,并探讨了含钒钛元素的氮化物析出相作为薄板坯连铸连轧流程制备取向硅钢中辅助抑制剂的可行性.研究表明,在所冶炼的含钒钛取向硅钢的成分范围内,Ti N在钢液凝固末期便具备析出的热力学条件,而Al N与VN只可能在凝固后的α+γ或α+Fe3C两相区内析出.含钒钛取向硅钢中氮化物析出相以成分复杂的复合析出相为主,且随着钒钛加入量的增加,钢中抑制剂析出相总的分布密度由于含钒钛元素的氮化物析出相的增加而明显提高,使抑制剂抑制初次再结晶晶粒正常长大的能力得以加强,最终成品的磁感应强度值B8由1.857 T提升至1.898 T.同时,加入不高于0.007%的Ti与不高于0.005%的V不会影响中间脱碳退火工序的脱碳效果以及高温退火净化阶段硫、氮的脱除效果,其形成的含钒钛元素的纳米级氮化物析出相适合作为薄板坯连铸连轧流程制备取向硅钢的辅助抑制剂. The precipitation behavior of nitride precipitates in grain-oriented silicon steel containing vanadium and titanium elements produced by thin slab casting and rolling process was studied by thermodynamic calculation and simulation experiment. The feasibility of nitride precipitates containing V and Ti elements as auxiliary inhibitors was also investigated. It is found that Ti N is likely to precipitate at the final stage of solidification in the grain-oriented silicon steel,but VN and Al N can p...
硅钢常化炉段工艺特征及问题分析
连续酸洗退火机组(CPAL)对于当前生产高磁感取向硅钢和高牌号无取向硅钢是必不可少的一个环节。常化炉是常化酸洗机组关键的组成部分。本文对国内自主建造的两条退火酸洗机组的工艺流程,特别是常化炉段进行了对比分析。总结出了常化炉的工艺及组成特点,对生产过程中暴露的问题进行了仔细的分析并提出了改进的意见,对于以后新建常化炉具有一定的提示作用。 The continous pickling annealing line(CPAL) is an essential step in producing high magnetic induction grain-oriented silicon steel and high grade non-oriented silicon steel.The normalizing furnace is a very important part of the CAPL.In this paper,the process flows of two CAPL with independent manufacture in our country have been compared,especially the part of normalizing furnaces.The characteristics of process and component are summarized and problems of the normalizing furnace during the prod...
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...
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...
无取向硅钢热轧卷结疤缺陷产生的原因及控制
针对不同牌号的无取向硅钢产生结疤缺陷的难易程度和表面结疤缺陷的外形特征及分布规律,分析了该缺陷产生的原因。通过调整剪前导板的对中度,设置精轧侧导板开度余量及短行程数值,及时修补与更换侧导板,减少带坯与侧导板挤撞程度,有效地降低了结疤缺陷发生率。 This article analyses the cause of the scab defects according to the defects appearance characters and distribution law,degree of difficulty to form scar of non-oriented silicon steel. It can effectively decrease the scabs by different methods,such as adjusting the center line of guide plate,setting the opening margin and short stroke value of the side guide on finishing mill,timely repairing and replacing of side guide,decreasing the collision between the strip and side guide.
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...
修正GTN模型及其在预测硅钢冷轧边裂中的应用
考虑剪应变对微孔洞损伤演化的影响,对GTN损伤模型的损伤演化机制进行修正,建立了适用于不同应力三轴度水平的损伤模型。结合隐式应力更新算法和显式有限元计算,采用VUMAT子程序实现了修正GTN模型在有限元软件ABAQUS中的数值计算。通过模拟纯剪切和剪切-拉伸两组试样的损伤演化和断裂行为,验证了修正GTN模型在不同应力三轴度承载条件下的有效性。运用修正GTN损伤模型模拟含边部缺口的带钢在轧制过程中裂纹的萌生和扩展行为,模拟结果与实验相一致,表明该模型可有效地用于带钢缺陷在轧制过程中扩展行为的分析和预测。模拟和实验结果表明,带钢边部缺口在轧制过程中,缺口前沿和后沿均会萌生裂纹,且后沿裂纹扩展更为明显。 Considering the effect of shear strain of micro-void on damage evolution, a modified GTN model applicable to various stress triaxiality conditions is proposed by modifying the damage evolution mechanism of the GTN damage model. The modified model is implemented in commercial finite element software ABAQUS by combining the implicit stress update method with an explicit finite element solving algorithm and through the user-defined material subroutine VUMAT. The damage evolution and the failure pro...
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...
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...
