冷轧无取向电工钢连续退火工艺模拟实验

将经CSP流程生产的、w（Si＋Al）=1.0%为基的冷轧无取向电工钢,在MULTIPAS模拟器上进行连续退火工艺模拟实验。结果表明：该钢种的热轧板卷经过压下率约75%的冷轧,得到的冷轧,板完全再结晶温度为700℃,经820℃×60 s退火可获得磁性和力学性能较好的全工艺型产品,经720～780℃×60 s退火可获得力学性能和磁性较好的半工艺型产品。在MULTIPAS模拟器上进行冷轧无取向电工钢的连续退火模拟,采用合适的涂层保护可防止钢材表面氧化;选取合适的升温及降温速度,可使退火后的板形满足磁性测量的要求。在MULTIPAS模拟器上,进行不脱碳的冷轧无取向电工钢的连续退火模拟是可行的。     

薄板坯连铸连轧生产电工钢现状及其优势

重点分析了薄板坯连铸连轧工艺生产电工钢的现状,与传统的厚板流程相比,分析了GSP工艺流程生产电工钢所具有的优势.     

无取向硅钢热轧析出行为研究

研究了CSP和传统流程生产无取向硅钢热轧板析出物特征。结果表明,热轧板中的析出物以Mn S、Al N以及二者的复合析物为主,并含有少量Ti(CN)和Cu2S析出。CSP流程生产的无取向硅钢中的析出物主要是Mn S、Al N,尺寸分布峰值在100 nm-200 nm之间,传统流程生产的无取向硅钢中析出物主要以Mn S为主,析出物尺寸分布峰值在150 nm-200 nm。     

C、N、S含量对无取向电工钢磁导率的影响研究

为了研究杂质元素对无取向电工钢磁导率的影响,结合工业化生产的Si+Al含量为0.55%的产品,探讨了不同含量范围的C、N、S杂质元素与磁导率间的对应关系,并提出了合理的杂质元素控制范围。     

不同晶体学平面对无取向电工钢电磁性能的贡献及其磁性各向异性

论证了不同晶体学平面对无取向电工钢电磁性能的贡献及其磁性各向异性。结果表明,不同晶面的这两项指标均与它们在极图上的位置有关,13个重要晶面对无取向电工钢磁感应强度的贡献依照以下次序降低：{100}-{310}-{411}-{521}-{210}-{110}、{431}、{321}和{211}-{221}-{332}-{433}-{111};而磁性各向异性则以{110}晶面最强,{111}晶面最弱,{111}晶面及其他晶面的磁性各向异性以{110}晶面的极点为中心呈放射递减状分布在反极图上。     

消除应力退火对半工艺电工钢组织和磁性能的影响

为改善半工艺电工钢产品的磁性能,借助NIM2000E电工钢交流磁性能测量系统,采用方圈测量方法研究消除应力退火工艺对半工艺电工钢磁性能、组织的影响。结果表明：在760~790℃×2 h退火时,组织为粗大均匀的等轴铁素体晶粒,平均晶粒尺寸在200μm左右,铁损P1.5/50小于3.5 W/kg,磁感应强度B50高于1.70 T,对应的磁导率μ1.0高于12.57 mH/m。     

6.5％Si电工钢的特性及应用

介绍了6．5％Si电工钢的特性及生产方式，同时叙述了该牌号电工钢国内外的发展及应用情况。     

Fe-3%Si电工钢的相图计算及组织分析

使用热力学软件分析了碳含量对Fe-3%Si的电工钢相图的影响,考察了奥氏体和铁素体两相区内两相相对量随温度的变化.结合金相法观察了不同加热温度及不同保温时间的淬火组织,初步确定了不同温度及不同保温时间下电工钢组织的形貌特征.     

六辊冷连轧机电工钢矩形断面控制弯辊力模型

为满足新一代高技术冷连轧机宽幅电工钢薄板等高端板材“Dead flat”矩形断面超平材超高板形质量要求,采用显式动力学有限元法建立六辊冷连轧机一体化仿真模型,利用现场工业轧制试验数据验证有限元模型的准确性,定量分析电工钢完整轧制过程中不同轧制因素对有载辊缝凸度的影响规律;基于6辊UCM冷轧机板形控制机理和课题组自主设计的EDW-N(Edge Drop Control Work Rolls for Non-shifting of the Work Rolls)工作辊非窜辊辊形建立六辊冷连轧机电工钢矩形断面控制的弯辊力数学模型;由有限元仿真与现场工业轧制试验结果确定了六辊冷连轧机电工钢矩形断面控制弯辊力数学模型的参数,并验证了其准确性;某大型1 420 mm六辊冷连轧机生产应用现场连续检测反馈数据表明：取得电工钢高精度出口凸度均值C15≤7μm的比例从38.58%提高到67.74%的显著生产实绩,充分发挥了六辊冷连轧机的高精度板形控制能力,可在很大调节范围内对板形质量进行调控,为解决无工作窜辊的6辊UCM冷连轧机宽幅电工钢薄板矩形断面控制瓶颈难题提供了解决方案和实现路径。     

有高温相变的电工钢热轧起浪的有限元分析

针对电工钢自由规程轧制过程起浪问题,开展电工钢不同冷却条件下的连续冷却相变转变温度分析测定和Gleeble热模拟实验,发现电工钢在975~875℃的奥氏体-铁素体两相区,随着轧制温度降低,变形抗力反而减小;电工钢大量同宽自由规程轧制下的工作辊出现严重的不均匀的箱型磨损和明显的热胀,综合辊形变化显著.考虑电工钢两相区变形抗力差异和综合辊形变化,建立电工钢热轧过程轧辊轧件的三维弹塑性耦合有限元模型,仿真分析轧制力、弯辊与窜辊对承载辊缝形状的影响,研究摩擦系数、压下量与轧制速度对带钢宽度方向内应力变化规律的影响,采用Shohet板形判据确定电工钢比例凸度残差变化路径,明确电工钢在"平坦死区"较大的上游机架出现"异常起浪"的生成过程.该方法为电工钢热轧板形的浪形控制提供了依据.     

Study on temper-rapid cooling process of low carbon steel produced by CSP

On the basis of the effect of carbon precipitation on the microstructure and properties of steel products below At temperature, a new thermal treatment method （temper-rapid cooling process） was studied. By the temper-rapid cooling process, the yield strengths of the high strength low carbon （HSLC） steel ZJ330 and SPA-H produced using the compact strip production （CSP） process increased from 340 to about 410 MPa and from 410 to about 450 MPa, respectively. The results indirectly indicated that there existed nanoscaled iron-carbon precipitates that have obvious precipitation effect on low carbon steel produced by CSP. The prospect of application is discussed.     

Grain refinement of low carbon steel produced by CSP process

In comparison with conventional production for hot strips, compact strip production (CSP) brings about some new micro-structural phenomena. Investigations were carried out to clarify the grain refinement mechanism of low carbon steel strips produced by the EAF-CSP process. Samples, obtained from the same rolling stock during continuous rolling, were examined through SEM,TEM and XEDS. Thin slabs have a dominant columnar structure and the spacing of the secondary dendrite arms ranges from 90 to ～125 μm. The average grain sizes for the central area of the samples from the 1st to 6th pass are 41.6, 25.2, 21.4, 20.2, 13.1, 6.7 μm,respectively. Large number of nanometer oxide and sulfide have been found in the low carbon steel produced by the CSP process.The grain refinement mechanism can be summarized as follows: finer solidification structure of the thin slab; austenite recrystalliza-tion at higher temperature and stain accumulation at lower temperature caused by the great reduction of single rolling pass during continuous rolling; nano-scaled precipitates of sulfide and oxide which drag grain boundaries of austenite or ferrite to prevent the grain coarsening.     

连续退火温度对马钢CSP-冷轧IF钢板塑性应变比r值的影响

针对连续退火工艺方法,研究了以CSP流程热轧卷为基料生产的IF冷轧卷退火温度对r值的影响。分析了加热温度、缓冷温度和快冷温度对r值影响的显著性,制定了连续退火温度的优化方案。     

Q235钢CSP过程组织及性能的转变

对包钢CSP线生产的Q235钢连铸坯及不同道次轧制后空冷的试样进行了组织观察,测定了硬度及力学性能.分析了CSP线生产的Q235钢组织、性能变化的原因.研究表明,随轧制道次的增加,变形后轧件的室温组织细化;沿铁素体晶界分布的珠光体变得均匀、弥散;力学性能较采用传统工艺制备的Q235钢有显著提高.     

冷轧超低碳钢带表面缺陷的研究与分析

针对马钢CSP工艺生产的某品种冷轧超低碳钢带表面缺陷进行了详细的统计和分析,同时对现场收集到的典型缺陷试样进行金相和扫描电镜分析,找出了钢带表面缺陷的种类、来源及分布的变化规律。对冷轧超低碳钢带表面缺陷分析发现缺陷主要是由具有结晶器保护渣特征的钙铝酸盐夹杂物、钙铝酸盐和硫化钙共生的夹杂物以及表面条状的氧化铁皮压入造成。本文根据表面缺陷分析研究的结果提出了相应的工艺控制措施,降低了表面缺陷的发生率。     

Microstructure homogenization control of Nb-bearing X65 pipeline steel by the CSP process

In order to get the controlled methods of microstructure homogenization and high strengthening-toughening combination by compact strip production (CSP) rolling,the dynamic recrystallization characteristics of each pass were obtained during CSP rolling using a Gleeble-1500 thermal mechanical simulator.Then,the CSP process was simulated by laboratory rolling experiment.Through thermal mechanical simulation experiment and laboratory rolling experiment,a design idea of Nb-bearing pipeline steel by CSP can be ob...     

Nano-scaled iron-carbon precipitates in HSLC and HSLA steels

This paper studies the composition, quantity and particle size distribution of nano-scaled precipitates with size less than 20 nm in high strength low carbon (HSLC) steel and their effects on mechanical properties of HSLC steel by means of mass balance calculation of nano-scaled precipitates measured by chemical phase analysis plus SAXS method, high-resolution TEM analysis and thermodynamics calculation, as well as temper rapid cooling treatment of ZJ330. It is found that there existed a large quantity of nano-scaled iron-carbon precipitates with size less than 18 nm in low carbon steel produced by CSP and they are mainly Fe-O-C and Fe-Ti-O-C precipitates formed below temperature A1. These precipitates have ob- vious precipitation strengthening effect on HSLC steel and this may be regarded as one of the main reasons why HSLC steel has higher strength. There also existed a lot of iron-carbon precipitates with size less than 36 nm in HSLA steels.