钢厂
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...
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...
硅钢连续退火炉无氧化加热段辐射换热研究
以能量平衡和辐射换热理论为基础,通过合理假定,建立了硅钢无氧化加热炉数学模型。采用数值计算的方法,通过自编程序,完成对带钢加热过程温度场的仿真。结果显示:数学模型能够反映带钢在无氧化炉内的加热过程,其升温曲线能够与工艺曲线相吻合;现行炉温分布并非最优,数学模型能够为炉温分布的优化、炉段的设计提供理论依据。 Mathematical model of NOF Section of Continuous Annealing Furnace is established based on energy balance and radiation heat exchange. The temperature field of steel is simulated by mathematical computation. The simulating results show that the mathematical model can reflect the heating process of silicon steel in NOF section, and the heat-up curve is coincide with the processing curve. From the results,it is known that the current furnace temperature gradient is not the best, and the mathematica...
双辊连铸无取向硅钢铸带特征及常化作用研究
双辊连铸技术是冶金及材料领域内的一项前沿技术,对于生产高品质硅钢具有独特优势.本实验研究了一种双辊铸轧w[Si]=4.5%的无取向硅钢,考察其铸态和常化处理后样品的组织、织构及析出相尺寸特征.结果表明:铸带组织以与铸带法向成5~20(°)倾角的柱状晶为主,晶内存在少量0.3~0.4μm的AlN析出相,铸带织构以λ(<001>//ND)织构为主,表层织构漫散.950℃/10 min常化处理后,析出相尺寸增大,表层λ织构增强. As an advanced technique of metallurgy and material science,twin- roll strip casting has unique advantages for producing high quality silicon steel. The present study was aimed at a 4. 5% Si non- oriented electrical steel for analyzing the structure,texture and the size of precipitates at the initial and normalized state. The results revealed that the initial structure mainly consisted of columnar grains with 5 ~ 20( °) angle to the normal of cast strip,and some AlN precipitates of 0. 3 ~ 0. 4 μ...
无取向电工钢XG800WR连铸电磁搅拌试验研究
采用铸坯低倍组织检验和化学分析的方法,研究板坯连铸机二冷区电磁搅拌器电流和频率参数对无取向电工钢XG800WR板坯中心偏析和等轴晶率的影响,结果表明:铸坯等轴晶率随着搅拌器电流强度和电流频率的增大而增加。采用二冷区电磁搅拌可减小中心易偏析元素S的偏析,试验得出:减小铸坯S偏析效果最好的电磁搅拌参数为电流380~400A,频率6Hz。 The effect of electromagnetic stirring current and frequency parameter at secondary cooling area on the central segregation and equiaxed crystal ratio of XG800WR non - oriented electrical steels slab was investigated through the methods of chemical and macrostructure analysis.The results shows that the rate of equiaxed crystal zone is going up with increasing of current intensity and current frequency.Electromagnetic stirring in the secondary cooling area can be easily reduced segregation caused...
微合金元素对冷轧取向电工钢再结晶行为的影响
以取向电工钢成分为基础,制备了含C或Mn和S的4种实验钢。观察了接近平衡析出状态实验钢经60%冷轧后在600~1000℃范围再结晶退火过程中微观组织演变,统计分析了再结晶体积分数随退火时间的变化规律,进而计算了各实验钢静态再结晶的激活能。观察了高含C实验钢退火初期再结晶晶粒优先出现的部位。结果表明900~1000℃范围内各实验钢铁素体的化学成分相似,因而其再结晶激活能基本一致。在600~800℃范围内铁素体内会有阻碍再结晶进程的三次渗碳体析出,从而使再结晶激活能明显提高。高C含量实验钢中还会有从奥氏体转变而来的粗大珠光体或渗碳体,轧制过程中其附近形成的变形区会促进600~800℃加热时该区域附近率先发生再结晶形核、降低再结晶激活能。固溶的Mn、S元素可微弱提高再结晶激活能,但高Mn、S含量会改变粗渗碳体从奥氏体析出时的形态。 Four experimental steels based on grain oriented electrical steel containing C,or Mn and S were prepared.Microstructure evolution of the steels close to a state of equilibrium precipitation were observed during annealing processes at 600-1000 ℃after 60% cold rolling,the changes of recrystallization volume fraction were analyzed statistically as the annealing was prolonged,and the activation energy for static recrystallization of the steels were calculated.The locations,where the recrystallizatio...
温度及扩散时间对CVD法制备高硅钢的影响
采用CVD法制备6.5%Si高硅钢,介绍了具体的制备工艺过程,研究了温度对渗硅速率和试样质量减轻的影响,同时分析了扩散时间对高硅钢中硅分布的影响。结果表明:在CVD反应过程中,反应温度高于1050℃将大大提高渗硅速率,但当温度大于1200℃后,渗硅速率趋于稳定;渗硅后,试样会减轻、减薄,随着温度升高,试样质量减轻的速率逐渐增大,在1200℃左右趋于稳定;扩散时间越长,硅分布越均匀,结合制备效率进行考虑,满足Δw表-中/b≤5的时间为适宜的扩散时间。 6.5%Si high silicon steel was manufactured by using CVD method and the process was introduced,the influence of temperature on the siliconizing rate and quality reducing rate,diffusion time on silicon distribution were investigated.Results as follows: the siliconizing rate will increase quickly when the temperature is higher than 1050 ℃,but the siliconizing rate will become steadily as the temperature up to 1200 ℃;The quality reducing rate will increase with the elevating of temperature and the r...
国外采用板坯低温加热工艺生产Hi-B取向电工钢最新进展
根据新日铁、JFE及浦项等国外钢铁公司2008年以来在日本专利局、欧洲专利局(EP)及世界知识产权组织(WIPO)申请公开的有关生产Hi-B取向电工钢典型专利技术,概述了近年来国外大型钢铁企业采用低温板坯加热(坯加热温度<1 280℃)技术生产Hi-B取向电工钢主要技术重点,即将调节关键化学成分Al、N、Sn及Sb等与工艺改进相结合。最后介绍了国外大型钢铁企业采用低温板坯加热技术生产Hi-B取向电工钢实例。 The latest developments on technology for manufacturing Hi-B grain oriented electrical steel sheets developed by Nippon Steel Corp.,JFE Steel and POSCO were described according to the patents published by World Intellectual Property Organization,Japan Patent Office and European Patent Office over the recent years.The low temperature slab heating process(particularly slab-heating temperature<1 280 ℃) together with suitably adjusting key chemical elements such as Al,N,Sn and Sb elements was the...
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...
氧硫交互作用对硅钢中非金属夹杂物生成的影响
结合工业化生产的无取向硅钢,探讨了氧硫交互作用对钢中夹杂物生成的影响。借助非水溶液电解+扫描电镜法,研究了不同O、S含量下钢中夹杂物的变化规律。结果表明,本实验条件下,提高O含量、降低S含量,会劣化热轧组织再结晶效果。在劣化效果上,O的作用大于S;低Si、无Al硅钢中,应尽可能降低O含量、适当提高S含量,以粗化钢中微细夹杂物,减少尺寸小于1.0μm的夹杂物的数量;O、S含量与钢中夹杂物数量不具有关联性。生产过程中,不仅要严格控制O、S含量,还要严格控制生产工艺,以免生成较多的有害夹杂物。 Based on the industrial production of non-oriented silicon steel,the effects of interaction between oxygen and sulfur on the formation of inclusions were discussed.The change of non-metallic inclusions in steel sheets was investigated by means of electrolysis with non-aqueous solution under different oxygen and sulfur content.Results show that the recrystallization microstructure of hot rolled sheets will be deteriorated with the increase of oxygen content and the decrease of sulfur content.The ...

