钢厂
无取向硅钢热轧边裂的形成原因
利用加热炉模拟、动态再结晶以及热模拟等试验方法以及扫描电镜、金相显微镜等分析观察手段对无取向硅钢边裂的成因进行了探讨。结果表明,长时间加热使得板坯边部晶粒异常长大,晶界氧化并脱碳,轧制过程中边部温度过低,动态再结晶过程变弱,使得板坯边部延伸性能变差,是导致硅钢边裂的主要原因。建议通过适当降低铸坯加热温度、缩短保温时间、提高终轧温度来改善硅钢边裂缺陷。 The behaviors of high temperature oxidation,dynamic recrystallization,and hot ductility,microstructure evolution were investigated on the non-oriented electrical steel sheets to discuss the formation of edge crack.The key causes of cracking was found to be the coarse as-cast microstructure,grain boundary oxidation and decarburization in reheating furnace,as well as reduced temperature at strip edge region during hot rolling process resulting in reduced hot ductility and lack of enough dynamic re...
Cr对含Nb高强无取向硅钢组织、织构及性能的影响
高强无取向硅钢主要应用于高速电机,要求其具备高强度和优异磁性能,但目前无取向硅钢的磁性能和强度难以兼顾。因此,设计并制备了添加微量Cr的含Nb高强无取向硅钢,通过光学显微镜、EBSD、万能拉伸试验机、四探针测试仪和磁性能测量仪等研究了Cr对含Nb高强无取向硅钢微观组织、织构、力学性能及磁性能的影响。结果表明,添加质量分数为0.5%的Cr抑制了热轧组织的回复,使常化和退火组织再结晶减弱,常化和退火后有利织构面积分数增加,不利织构面积分数减小。添加质量分数为0.5%的Cr使含Nb无取向硅钢的屈服强度显著增大,磁感略升高,但对铁损几乎没有影响。Cr对屈服强度的影响一方面是由于Cr的固溶强化作用,另一方面Cr促进了Nb的析出而使Nb的析出强化效果增强;而Cr提高含Nb高强无取向硅钢的磁感主要是由于促进有利织构形成的同时抑制了不利织构的形成,使得织构因子增大;添加Cr使无取向硅钢的电阻率增加从而使铁损降低,同时Cr促进了Nb的析出,而这种富Nb析出相不仅抑制晶粒长大且会阻碍磁畴移动而使铁损增高,在两方面因素的综合作用下,添加质量分数为0.5%的Cr对含Nb高强无取向硅钢的铁损几乎没有影响。因此,... High strength non-oriented silicon steel is mainly used in high-speed motors, which requires good mechanical and magnetic properties. However, it is difficult for non-oriented silicon steel to obtain high strength and good magnetic properties at the same time. In this paper, the Cr-microalloyed Nb-containing high strength non-oriented silicon steel was designed and prepared. The effect of Cr on the microstructure, texture, mechanical properties and magnetic properties of Nb-containing high stren...
轧制法制备低铁损高磁感6.4%(质量分数)硅钢及其织构演变
采用轧制法制备出具有低铁损高磁感0.23mm厚6.4%(质量分数)Si高硅钢。沿轧制方向的最终磁性能为B8=1.474 T,B50=1.714 T;P10/50=0.30W/kg,P15/50=0.88W/kg。利用X射线衍射及背散射电子衍射(EBSD)技术分析了高硅钢在轧制及退火过程中的织构演变过程。结果表明,通过采用大压下率热轧,确保热轧板次表层中产生更多的高斯织构,随后进行遗传;温轧板中粗大的晶粒有利于冷轧剪切带的形成;冷轧板经脱碳退火后生成强{210}〈001〉织构及次表层较强的高斯织构是在轧向上获得高磁感的原因,归因于其在{111}〈112〉冷轧形变晶粒内的剪切带优先形核并长大;最终退火后虽出现了随机取向,但以{310}〈001〉织构为代表的η织构得以保留并且增强,进一步提高了磁感。随着退火温度的升高及保温时间的延长,高硅钢薄板晶粒尺寸不断增大,铁损明显降低。 6.4wt%Si high silicon steel sheets(0.23mm thick)with low iron loss and high magnetic induction were successfully produced by rolling process.The final magnetic properties along the rolling direction(RD) were:B8=1.474T,B50=1.714T;P10/50=0.30 W/kg,P15/50=0.88 W/kg.The texture evolution during rolling and annealing was investigated by means of X-ray diffraction and electron backscatter diffraction(EBSD).It was found that more Goss textures formed in the subsurface of hot rolled plates by using larg...
6.5%Si高硅钢铸锭凝固组织的CAFE法模拟研究
应用CAFE法对6.5%Si高硅钢铸锭凝固组织进行了模拟研究,确定出了适合高硅钢组织模拟的模型。进一步用该模型研究了过热度及冷却条件对凝固组织的影响,结果表明,随着过热度的降低,凝固组织中柱状晶比例和晶粒平均面积均减小。水冷条件下,高硅钢铸锭凝固组织几乎全是柱状晶,而且晶粒粗大。空冷条件下,等轴晶区扩大,但柱状晶仍占主要部分。缓冷条件下,等轴晶区占主要部分,晶粒平均面积和空冷条件下相当。 The solidification structure of 6. 5% Si steel ingot was simulated based on CAFE method and the model suitable for simulating the structure of high silicon steel wad ascertained. The influence of superheat and cooling condition on the solidification structure were studied. It was shown that with the superheat decreasing,the proportion of columnar crystals decrease,and the average grain size become smaller. Under water cooling condition,the solidification structure of casting was composed of almo...
无取向电工钢边部减薄控制技术研究
叠片系数是冷轧无取向电工钢的重要质量指标。为了提高叠片系数,必须保证无取向电工钢板形良好以及横向厚差小。针对攀钢冷轧厂4机架HC轧机轧制无取向电工钢的边部减薄问题,以无取向电工钢横向厚差最小作为目标函数,建立了一套针对无取向电工钢边部减薄控制的辊型曲线优化数学模型,开发了无取向电工钢专用辊型曲线,使无取向电工钢横向厚差从25μm降低到10μm以下,取得了良好的控制效果。 The lamination factor is an important quality index of non-oriented silicon steel strip.Considering the lamination factor,the non-oriented silicon steel must have a good shape and a smaller transverse thickness difference.In order to solve the edge thinning of non-oriented silicon steel strip in Panzhihua Steel,a mathematic model for designing the roll shape is built.In the model,the transverse thickness difference of non-oriented silicon steel strip is taken as the objective function.Based on t...
硅钢连退机组无氧化炉加热能力计算
无氧化炉具有加热效率高、投资与运营成本低、作业率高、表面质量及板型良好、NOx排放相对低等优势,在硅钢热处理领域应用前景广泛。本文阐述了确定无氧化炉(NOF)加热能力详细过程,涵盖炉温、炉断面尺寸、炉长、热平衡结算、加热能力计算等,为今后无氧化炉(NOF)在硅钢热处理应用时的设计提供了借鉴,同时也为今后明火直接加热的工业炉设计提供了参考。 Non-oxidation furnace has the advantage s of high heating efficiency, low investment and operation cost, high operation rate, good surface quality and plate shape, and relatively low NOxemission,and it still has wide application prospect in the field of silicon steel heat treatment. The detailed process of determining the heating capacity of a non-oxidizing furnace(NOF) is described, covering furnace temperature, furnace section size, furnace length, heat balance settlement, heating capacity cal...
夹杂物尺寸及数量对无取向硅钢磁性能影响的主成分回归分析
采用扫描电镜、场发射扫描电镜、能谱仪等对50SW1300冷轧无取向硅钢中的夹杂物分不同尺寸区间进行数量统计,利用主成分回归分析法,即数据的标准化处理—主成分分析—回归分析—标准化的变量还原成原始变量—确定显著影响因素,综合分析夹杂物总量及各尺寸区间的夹杂物数量对无取向硅钢磁性能的影响。结果表明:主成分回归分析能够从夹杂物尺寸区间及数量的多个影响因素中提取主要的因素,定量研究其对磁性能的影响。分析表明,显著影响无取向硅钢铁损的夹杂物为100~500nm的AlN、AlN+MnS、MnS、Al2O3、AlN+Al2O3,而劣化磁感最明显的夹杂物尺寸区间为100~200nm。 Different size intervals of inclusions in cold rolled non-oriented silicon steel 50SW1300 were counted by scanning electron microscope(SEM),field emission scanning electron microscope(FESEM)and energy disperse spectroscopy(EDS).With principal component regression method:standardization for experimental data,principal component analysis,regression analysis,transform standardized variables into original variables,determination of significant factor,effects of the total number of inclusions and the...
固溶处理对高牌号无取向硅钢磁性能的影响
对商用50W330型无取向硅钢成品在930℃下保温2 h固溶并以不同方式冷却处理,利用磁性检测仪检测分析了处理前后的磁感和铁损变化,应用光学显微镜、扫描电子显微镜、X射线衍射仪观测分析了显微组织结构的演变。考察了平均晶粒尺寸、织构组分比及第二相粒子状态对磁性能的影响规律,结果表明:固溶处理前后平均晶粒尺寸的变化对硅钢磁性能的影响非常显著;当平均晶粒尺寸相差不大时,织构组分比[Goss+{100}]/{111}越大,磁感会越高;固溶处理会将细小弥散的第二相粒子重新回溶到基体中,减小了其对磁畴壁的钉扎作用,铁损随之下降。 The commercial 50W330 non-oriented silicon steel samples were heat treated at 930℃ for 2 h and cooled in different ways,then the iron loss and the magnetic induction of the samples before and after solution treatment were measured with a magnetic detector.The evolution of microstructural texture was analyzed by optical microscopy,scanning electron microscopy and X-ray diffractometry.The effects of average grain size,texture composition ratio and the second phase particles on the magnetic propert...
高硅钢薄板退火过程中的织构演变
采用传统的轧制和退火工艺制备了0.30mm厚的6.5%(质量分数)Si高硅电工钢薄板,采用X射线衍射技术对退火过程中的再结晶织构进行了研究。冷轧高硅钢薄板700℃退火形成以{111}〈112〉为峰值的γ织构(〈111〉∥ND)和以{001}〈210〉为峰值的{001}织构;而900℃以上温度退火则形成强{001}〈210〉织构。进一步的研究表明是在晶粒长大过程中{001}〈210〉发展成为主要再结晶织构组分。 High silicon steel thin sheets with thickness of 0.3mm were successfully produced by conventional rolling and annealing methods.Recrystallization texture was investigated by means of X-ray diffraction.It is found that recrystallization texture is mainly composed of γ fiber(〈111〉∥ND)with peak at {111}〈112〉 and {001} fiber with peak at {001}〈210〉 after annealing at 700℃,while strong {001}〈210〉 component dominates recrystallization texture after annealing above 900℃.It is during grain growth that {...
薄带连铸取向硅钢的热轧孪生行为
薄带连铸流程下取向硅钢粗大λ晶粒(〈100〉//ND,normal direction)的“遗传”会导致磁性能恶化.为解决这一问题,针对取向硅钢的热轧孪生行为开展研究,结果表明:凝固组织粗大的取向硅钢在650℃热轧时可产生大量{112}〈111〉形变孪晶,这与具有高层错能的硅钢在较高温度下难以孪生变形的传统认知不同.热轧过程中复杂的应力状态降低了变形孪晶的取向依赖性,由于具有更高的储存能,孪晶界/孪晶界及孪晶界/晶界交叉点成为再结晶形核的优先位置,大大提高了常化过程中的再结晶率,受沿孪晶界应变分布及孪晶间距离的限制,沿孪晶界形核的再结晶晶粒通常呈“饼状”,最终形成以细小且取向漫散的再结晶晶粒为主的常化组织,消除了初始凝固组织中有害的粗大λ晶粒. In strip casting grain-oriented silicon steels, the inheritance of coarse λ grains(〈100〉//ND, normal direction) can deteriorate their magnetic properties. To solve the problem, twinning behaviors in strip casting grain-oriented silicon steels during hot rolling were investigated in this work. It is found that after rolling at 650 ℃, a number of {112}〈111〉deformation twins are formed in the coarse solidification microstructure of the steels, in contrast to the well-accepted view that it is diffic...
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...