钢厂
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 ...
高温退火气氛对硅钢表面硅酸镁底层形貌的影响
对取向硅钢在不同气氛下的高温退火工艺进行实验室模拟,利用X射线衍射仪(XRD)分析了硅钢退火至900℃和1170℃时的样品表面氧化层和底层的物相组成,采用场发射扫描电镜(SEM)观察了样品表面氧化层和底层在截面方向上的微观形貌特征,并计算了高温退火一次升温阶段氧化反应的吉布斯自由能以及900℃时退火气氛的氧分压。结果表明:当退火气氛的露点温度保持一定时,较高的氢气含量有利于生成完整连续的底层;当退火气氛的水氢分压比保持一定时,在露点温度与氢气含量两者较低的条件下,底层附着性不佳易脱落,较高条件下,底层中夹杂着较多的铁单质;当氧化层中无FeO时,底层完整连续但易脱落,当FeO层较薄时,底层下方存在部分未反应的SiO2,当FeO层较厚时,底层不完整连续且有分层。 The high temperature annealing process of grain-oriented silicon steel in different atmospheres was simulated in the laboratory. X-ray diffractometer(XRD) was used to analyze the phase compositions of the surface oxide layer and forsterite film of the silicon steel annealed to 900 ℃ and 1170 ℃. Field-emission scanning electron microscopy(SEM) was used to observe the micro morphology characteristics of the surface oxide layer and forsterite film of the samples in the cross section direction. The ...
高硅钢温轧过程压下率及中间退火对组织、织构的影响
传统轧制法制备6.5wt.%高硅钢过程中温轧工艺具有显著不同于3 wt.%Si的电工钢的特点及组织织构特征,是开发新型基于织构优化的高硅钢的关键环节。采用EBSD技术对通过热轧、温轧、冷轧及退火工艺制备0.3mm厚的6.5wt.%Si电工钢板的组织和织构进行分析,重点研究温轧过程中的中间退火和大、小压下率组合以控制织构。结果表明,在热轧退火板是部分再结晶组织的情况下,一次性温轧或先小形变量、中间退火后再大形变量的工艺可得到更多的Goss晶粒;经过最终退火后Goss取向会发生偏转,形成部分黄铜取向,而{111}〈112〉取向的晶粒内形核生成近Goss取向的再结晶晶粒;大压下量轧制是最终组织中{111}取向晶粒较多的主要原因。 Warm rolling,a key process of developing new type high-Si electrical steel based on texture optimization,has significant different characteristics from 3wt% Si steel in conventional preparing process. 0. 3mm thickness 6. 5wt. % Si steel,obtained by a series of processes including hot and warm rolling,intermediate annealing and then cold rolling,was analyzed from microstructure and texture by EBSD,which are utilized mainly for investigating the intermediate annealing process and the combination o...
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...
压下率对取向硅钢热轧板织构的影响
采用X-射线衍射分析技术测定了取向硅钢热轧板在不同压下率下不同厚度处的织构。结果表明,在压下率低于80%的情况下,几乎所有试样的不同厚度处的织构均为旋转立方织构类型{100}<011>,但不同压下率、不同厚度处的织构强度存在很大差异;在压下率大于80%的情况下,不同试样的不同厚度处的织构类型发生了变化,其织构类型为旋转立方织构或高斯织构{011}<100>,且当织构类型为旋转立方织构时,织构强度存在很大差异,而当织构类型为高斯织构时,织构强度差异相对较小。 The texture of the grain oriented silicon steel hot rolled plate at different compressibility has been measured.The experimental results have shown that the texture of all samples at different thickness is {100}<011> when the compressibility is below 80%,and its intensity at different compressibility and thickness is difference.The texture of all samples at different thickness is variable when the compressibility is above 80%,it is {100}<011> or {011}<100>,and the intensity of ...
50W600无取向硅钢钙处理的热力学分析及实验研究
通过热力学计算及实验室研究,对钙处理前后50W600无取向硅钢退火冷轧板中夹杂物的类型、数量及尺寸进行了系统分析。结果表明,50W600无取向硅钢经钙处理后(w(Ca)=0.002 6%),钙在1 600℃的钢液中主要以固态的CaO·2Al2O3、CaO·6Al2O3及溶解钙的形式存在。在钢液的凝固过程中,钢中的溶解钙和硫反应生成了CaS和CaS-MnS复合夹杂,有效抑制了MnS的弥散析出,减少了钢中微细夹杂物的数量。同时钙处理促进了钢中微细夹杂物的聚合长大,导致显微夹杂物的数量增加。 Based on thermodynamic calculation and laboratory experiment,the type,quantity and size of inclusions in annealed cold-rolled steel sheets of 50W600 non-oriented silicon steel before and after calcium treatment were systematically studied.Results showed that after calcium treatment(w(Ca) = 0.002 6%),calcium was mainly in the form of CaO·2Al2O3,CaO·6Al2O3 and dissolved calcium in steel at 1 600 ℃.Dissolved calcium could combine with sulfur to form CaS inclusions and compound CaS-MnS inclusions du...
无取向电工钢硫含量控制技术研究
针对采用含钒铁水生产无取向电工钢存在的铁水脱硫率低、转炉冶炼过程回硫量大、成品硫含量偏高的问题,通过对含钒钛铁水脱硫,减少转炉冶炼过程回硫以及RH脱硫技术等方面的研究,大幅度降低了电工钢成品硫含量。生产表明钢中w(S)=0.001 9%~0.006 9%,平均为0.004 2%;w(S)≤0.008%的比例达到了100%,且w(S)≤0.005%的比例也达到了91.43%。 In cognizance of the problems of low desulphurization rate for hot metal,large sulfur-recovery in converter as well as high sulfur content in products in producing non-orientation electrical steel with vanadium-content hot metal countermeasures have been carried out.Sulfur content in non-orientation electrical steel is decreased obviously by way of study on technologies of desulphurization for hot metal with vanadium & titanium,sulfur-recovery control in converter and desulphurization in RH ...
高温硅钢加热炉双蓄热燃烧技术的探讨
介绍了双蓄热燃烧技术的特点和高温硅钢加热炉的特点,探讨了双蓄热燃烧技术在高温硅钢加热炉中使用的技术难点,分析了双蓄热燃烧技术在高温硅钢加热炉上使用的可能性。 Introduced characteristics of double regenerative combustion technology and high temperature silicon steel reheating furnace,discussed technical difficulties for using double regenerative combustion technology,analyzed the possibility of double regenerative combustion technology applied to high temperature silicon steel reheating furnace.
取向硅钢中含铜抑制剂的固溶析出行为
含铜抑制剂作为取向硅钢的主抑制剂或辅助抑制剂不仅可以抑制初次晶粒的长大,促进二次再结晶,还可以降低铸坯的加热温度。取向硅钢中主要抑制剂为10~50 nm Cu2S,在钢的铸坯、热轧、冷轧、脱碳等工艺过程均可析出;(Cu,Mn)1.8S、Cu1.8S、ε-Cu等主要作为辅助抑制剂,尺寸一般为30~50 nm(或大于50 nm),主要在热轧阶段析出。总结了国内外有关取向硅钢中含铜抑制剂析出行为的研究进展,当前主要研究不同生产流程和工序中含铜抑制剂的析出行为和作用机理。 As main inhibitor or auxiliary inhibitor for grain-oriented silicon steel,the particles of inhibitor bearing copper not only inhibit the primary crystal growing and promote the secondary recrystallization,but also decrease the heat temperature of casting slab.The main inhibitor for grain-oriented silicon steel is 10~50 nm Cu2S,which precipitate in process and procedure including steel casting slab,hot rolling,cold rolling and decarburizing process,while the 30~50 nm or more than 50 nm...
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...

