钢厂
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 ...
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.
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...
取向硅钢连续退火的工艺与设计
分析了影响脱碳效果和结晶行为的各种要素及其相互制约关系,提出了Hi-B连续退火工艺曲线,总结得出快速加热及合理稳态气氛是实现工艺制度的关键。结合实际工程,介绍了在连续退火炉设计中快速加热和气氛设计的考虑方法,并指出随着Hi-B产品的发展,如何改进这些方法将是连退工程研发的方向之一。 The factors which affect decarbonization and crystallization and the mutual restriction between them were analyzed.A complete continuous annealing process for Hi-B was put forward.As a result,the rapid heating and the proper steady atmosphere were two important factors.According to an actual project,the consider methods for designing rapid heating and proper steady atmosphere were introduced,and it is pointed that with the development of Hi-B technique,how to improve these techniques would be on...
冷轧压下量对取向硅钢极薄带显微组织的影响
观察了取向硅钢极薄带经冷轧至不同厚度,并经过不同工艺热处理后的显微组织及亚结构。结果表明:冷轧压下量越大,显微组织中位错密度越高,冷变形组织越多,等轴晶粒越少;增加冷轧压下量可以使试样的再结晶温度降低,当钢带厚度为0.08 mm时,在650℃退火时就能发生明显的再结晶。 Microstructure and substructure of the grain oriented ultra-thin silicon steel sheets is analyzed,which are rolled down to different thickness and treated with different heat treatment process.The result shows that there are higher dislocation density,more cold deformation structure and less equiaxed crystal grain in microstructure of the steel sheets with more cold rolled reduction.Increase of cold rolled reduction will decrease recrystallization temperature,and when thickness of the steel shee...
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...
罩式炉常化工艺对热轧硅钢50W350组织和性能的影响
研究了罩式炉常化工艺对50W350硅钢热轧板组织、夹杂物和性能的影响。研究结果显示,罩式炉常化工艺在温度一定的情况下,随着保温时间延长,硅钢晶粒逐步再结晶并长大,同时析出物也在聚集长大。通过制定合理的罩式炉常化工艺,可以实现硅钢晶粒的再结晶和长大,从而达到连续退火炉常化工艺产品技术要求。 The influence of normalization process with a bell furnace on the structure,inclusions and properties of 50W350electrical steel hot-rolled sheet was studied.The research results showed that:when the steel was normalized at a certain temperature in the bell furnace,the silicon steel grains gradually recrystallized and grew up with the extension of the annealing holding time,and at the same time,the precipitates also gathered and grew up.The recrystallization and growth of the silicon steel grains...
电工钢中柱状晶对热轧和退火时晶粒取向及组织的影响
利用EBSD技术研究了电工钢中长轴平行于轧向的柱状晶样品在热轧和退火过程中组织和取向的演变规律,并与长轴平行于板法向的样品的已有研究结果进行对比。结果表明,无论柱状晶按何种方向排列,只要表面存在剪切力,热轧后都可形成剪切织构,同时中心形成轧制织构,主要包括旋转立方织构和{112}<1-10>。柱状晶造成的影响主要体现在板中心层,长轴平行于轧向排列的样品热轧时形成的粗大旋转立方晶粒要到脱碳退火后才能完全消除,但破坏了正常的不同取向晶粒间的取向差分布及尺寸均匀性,导致二次再结晶不完全及磁性能降低。 The evolution of microstructure and grain orientation in an electrical steel containing columnar grains with its long axis being parallel to the rolling direction of sheet was studied during hot rolling and annealing by EBSD technique.The results are compared with those of samples containing columnar grains being parallel to normal direction of sheet reported in the reference [3].It was shown that,whether the long axis of columnar grains was arranged in RD or ND,shear textures can be formed in t...
硅钢车间ST机组粉尘调质与除尘系统改造
针对某硅钢车间ST机组的除尘系统除尘效率较低、排放浓度不达标、二次污染较严重的问题,通过现场调研,对除尘系统、含尘气体组分与物性参数等进行测试和分析,运用管道伴热技术改善粉尘黏性后,再选取合适的除尘器对粉尘进行除尘处理,大大地提高了系统的除尘效率。 To solve the problems of low dust removal efficiency, substandard emission concentration and severe secondary pollution, some investigations are conducted to test and analyze the dust removal system,dust-gas composition and relevant physical parameters.Moreover, dust removal efficiency is greatly improved by the use of pipe heat tracing technology and by choosing appropriate dust remover.
脱碳温度和脱碳时间对CGO取向硅钢碳含量控制的试验研究
通过测试取向硅钢不同工艺条件下的碳含量,探讨了CGO取向硅钢碳含量控制的最优处理条件,研究了脱碳温度和脱碳时间对相同初始碳含量取向硅钢的脱碳效果的影响。结果表明,在气氛为(15%~20%)H2+(75%~80%)N2,炉压差为10~20 Pa的条件下,CGO取向硅钢合适的脱碳温度为1 073 K~1 123 K,脱碳时间为10~20 min。在该处理条件下,能取得较好的脱碳效果。 By means of testing carbon content of oriented silicon steel below the distinct technical conditions,inquires the excellent handle terms of carbon content controlling for CGO oriented silicon steel,studies effects of decarburization annealing temperature and decarburization annealing time to the oriented silicon steel decarburization efficiency in same initial carbon content.The results show that,under the condition of atmosphere(15% ~ 20%) H2+(75% ~ 80%)N2 and furnace pressure difference 10 ~ 2...
冷轧无取向硅钢冶炼过程炉渣分析
对冷轧无取向硅钢在冶炼过程中各个工序的顶渣进行了检测,分析了顶渣变化原因,并得出结论:硅钢生产宜采用复吹转炉,以降低吹炼终点渣中TFe含量,进而减轻对精炼的压力;使用低S、低Al2O3含量中间包覆盖剂;RH脱氧及合金化顺序采用先加硅铁后加铝;首罐宜经LF提温并降低渣中TFe。 The top-surface slag used for the various production processes in smelting coldrolled non-oriented electrical steel is tested and based on tested results the cause of the top surface slag change is analyzed.So it is concluded that the combined blown converter is more suitable to be used for smelting electrical steel in order to reduce the content of TFe in slag at blow end point and then much better results can be achieved during the period of refining.Secondly the tundish flux contenting low co...

