硅钢绝缘涂层的研究进展

本文系统介绍了取和硅钢与无取向硅钢表面绝缘涂层，包括有机涂层，无机涂层和半无机涂层三大类，无机涂层和半无机涂层三大类，无机涂层具有良好的耐热和焊接性能，介其冲制性和粘结性不佳，半无机涂层具有良好的冲制性和粘结性，但共耐热性和焊接不及无机涂层，另外，最新研究的取向硅钢表面物理气相沉积ＴｉＮ，ＣｒＮ和ＴｉＣ绝缘涂层要使硅钢获得极低铁损，大大提高了硅钢的磁通量密度，并具有优异的耐热，焊接，冲制和粘结性。     

无取向硅钢表面绝缘涂层

无取向硅钢表面绝缘涂层包括有机涂层、无机涂层和半无机涂层三大类。无机涂层的基本成分是磷酸盐涂料和磷酸铝涂料中添加胶态二氧化硅、氧化镁和硼酸，它具有良好的耐热和焊接性能，但冲制性和粘结性不佳。半无机涂层基本成分为磷酸盐、铬酸盐、乳胶树脂溶液、弥散促进剂和表面活性剂，其中弥散促进和表面活性剂对涂层的质量有重要作用。半无机涂层具有良好的冲制性和粘结性，但其耐热性和焊接性不及无机涂层，有机涂层则已被逐渐淘     

高硅钢用半有机绝缘涂层的制备及其性能研究

为减少高硅钢铁芯叠片间的涡流损耗,以磷酸二氢铝、苯丙乳液、甘油及水为主要原料,制备出一种适合高硅钢用无铬环保半有机绝缘涂层.利用光电子谱仪、扫描电镜及能谱仪对高硅钢脱碳退火板的氧化薄膜、绝缘涂层的微观结构形貌及部分缺陷进行分析,并研究了该涂层的涂覆量对其附着性、硬度及绝缘性能的影响.研究结果表明:普通无取向硅钢磷酸盐环保半有机绝缘涂层同样适用于高硅钢;绝缘涂层的均匀性取决于高硅钢片表面的平整度、涂辊表面质量以及对涂覆速度的平稳控制;高硅钢的表面粗糙度及氧化膜厚度对绝缘涂层的附着性有着重要影响;本试验制备的半有机涂层每面涂覆量控制在0.8~1.2 g/m2,具有良好的附着性及绝缘性能,层间电阻在5Ω·cm2/片以上.     

取向硅钢横剪切口边缘绝缘涂层的破损形貌分析

采用斜刃横剪的加工方式对厚度为0.23mm的取向硅钢进行加工,研究加工过程中取向硅钢表面绝缘涂层的破损情况。在剪切加工过程中,取向硅钢表面由T2涂层(磷酸铝)与C2涂层(硅酸镁)组成的绝缘涂层在刀具作用下发生破损,其破损形貌分为裂纹区、压碎区以及剥落区。裂纹区和剥落区出现在塌角侧表面,而压碎区出现在毛刺侧表面。随着剪切侧隙的增加裂纹区宽度增大,压碎区基本保持稳定,剥落区略微增加。随着剪切速度的增加,毛刺侧表面涂层破损宽度先减小后增大。同时可观察到剥落区绝缘涂层发生了两种剥离形式,一种是T2涂层与C2涂层之间的层间剥离,另一种是C2涂层与基体之间发生的界面剥离。     

添加硼酸和钨酸铵对取向硅钢无铬绝缘涂层的影响

本工作研究了添加硼酸和钨酸铵对取向硅钢无铬绝缘涂层的显微组织和性能的影响.结果表明:在无铬磷酸盐绝缘涂液中适当地加入硼酸和钨酸铵可以显著提高涂液在取向硅钢基片上的润湿性,绝缘涂层表面变得致密光滑,且提高了涂层与硅钢基片的结合质量.涂液中复合添加2.0％(质量分数)硼酸和0.5％(质量分数)钨酸铵所制备的绝缘涂层对硅钢的综合性能提升效果最好,含有该涂层的取向硅钢的叠装系数为98.2％,铁损P17/50为1.155 W·kg-1,磁感应强度B8为1.876 T,层间电阻为19366Ω·mm2.此外,绝缘涂层的耐吸湿性和硅钢的耐腐蚀性也有所提高.     

取向硅钢表面绝缘涂层微结构与耐腐蚀性能

采用X射线衍射仪、扫描电镜、能谱分析仪和电化学工作站分别研究取向硅钢表面绝缘涂层的相成分、微观形貌、元素分布和耐腐蚀性能。结果表明:绝缘涂层为双层复合结构,底层为Mg_2SiO_4相,厚度为0.8μm;顶层为AlPO_4相,厚度为1.4μm;两层结合处存在0.4~0.6μm的扩散层。与只涂单层Mg_2SiO_4相的试样相比,双层涂层试样具有更高的腐蚀电位和极化电阻,更低的腐蚀电流密度,因此耐腐蚀性良好。随着浸泡时间的延长,腐蚀溶液逐渐渗透至硅钢基底,发生腐蚀反应,其腐蚀过程可以分为3个阶段。     

钨酸钠对取向硅钢绝缘涂层性能的影响

采用扫描电镜、爱波斯坦方圈、绝缘电阻测试仪、红外光谱仪和热分析仪等手段研究取向硅钢绝缘涂液中钨酸钠对制备的磷酸盐绝缘涂层微结构和性能的影响。结果表明:随着钨酸钠含量的逐渐增加,涂液与取向硅钢基底的润湿角先减小后增大;取向硅钢的层间电阻、叠装系数和磁感应强度均先增大后减小,铁损先减小后增大。当钨酸钠含量为2.0%(质量分数)时,涂液与硅钢基底的润湿性能最好,润湿角为39.3°;涂层致密、平整,绝缘涂层与硅酸镁底层之间存在0.8μm左右的过渡层,而且涂层的耐吸湿性能并不产生显著变化;取向硅钢的层间电阻、叠装系数、磁感应强度和铁损均达到最佳值,分别为14073Ω·mm~2,97.0%,1.893T和1.051W·kg~(-1)。     

ZnO对无铬无取向硅钢绝缘涂层性能的影响研究

主要研究了氧化锌对以Al(H2PO4)3为基料的无铬无取向硅钢绝缘涂层各项性能的影响.用盐雾实验和动电位极化研究了不同氧化锌含量对硅钢绝缘涂层的耐蚀性和电化学行为的影响.采用SEM和体视显微镜对涂层的表面形貌和附着性能进行研究.结果表明,氧化锌含量为4.0%时,氧化锌能完全中和涂层表面的游离磷酸,涂层的耐蚀性和附着性最好;氧化锌含量过少或过多时,涂层的耐蚀性和附着性都较差.     

退火温度对耐热型取向硅钢组织与磁性能的影响

采用OM和EBSD技术对两种耐热型取向硅钢的微观组织进行了检测分析，研究了不同退火温度下组织的变化规律及耐热机理。结果表明：齿状辊沟槽法是在带材表层形成小晶粒组织和“缝隙”,激光照射法是在带材表层形成“V”字型沟槽。激光照射法取向硅钢耐热温度约为850℃,齿状辊沟槽法取向硅钢耐热温度约为800℃,前者耐热性更为优异。随着退火温度的升高，两种带材的损耗逐渐升高。齿状辊沟槽法取向硅钢损耗升高主要是刻痕区与两侧的Goss晶粒取向差降低所致，而激光照射法取向硅钢损耗升高可能与沟槽附近处Goss晶粒取向的变化有关。     

树脂含量对半无机型无铬无取向硅钢涂层性能的影响

本文研究了丙烯酸树脂含量对以Al(H2PO4)3为基料的无铬无取向硅钢绝缘涂层各项性能的影响.用盐雾实验、动电位极化及交流阻抗等试验手段研究了不同树脂含量对硅钢绝缘涂层的耐盐雾性能和电化学行为的影响,同时采用SEM对涂层的表面形貌和附着性进行研究.结果表明,树脂含量为19.9~29.4%时,涂层的耐蚀性和附着性最好;树脂含量过多时,涂层的耐蚀性和附着性均较差.     

Primary Recrystallization of Grain Oriented Silicon Steel Strip Rolled by CSR and Annealed in Magnetic Field

The magnetic properties and textures of grain oriented silicon steel with different thickness rolled by cross shear rolling (CSR) of different mismatched speed ratio (MSR) and annealed in magnetic field under hydrogen were presented. Effects of the factors such as thickness and mismatched speed ratio on the magnetic properties and recrystallization texture were analyzed and the recrystallization principles in magnetic field annealing were discussed. The study would provide a new route for mass production of high quality ultra-thin grain oriented silicon steel strip.     

Magnetic properties of grain oriented ultra-thin silicon steel sheets processed by conventional rolling and cross shear rolling

A new procedure consisting of the cross shear rolling (CSR) and the subsequent tertiary recrystallization annealing under dry hydrogen atmosphere was developed to produce the grain oriented ultra-thin silicon sheets less than 0.1 mm with high magnetic property performance. For comparison, the conventional rolling (CR) was also used to process the grain oriented ultra-thin silicon steel sheets. The effect of processing parameters on magnetic properties of the grain oriented ultra-thin silicon steel sheets was investigated. With the increase of annealing temperature and holding time, magnetic properties of the sheets processed by both rolling methods reach saturation as the result of the proceeding of the tertiary recrystallization. The thin sheets rolled by CSR did achieve better magnetic properties than those rolled by CR.     

高品质取向硅钢成分控制的新进展及其对钢磁性能的影响

分析了高品质取向硅钢中合金元素硅和抑制剂形成元素成分控制的要求及水平,评价了常用的硫化物、氮化物抑制剂及晶界偏析元素铬、锡和铌在高品质取向硅钢中的应用现状,结合抑制剂对钢坯再加热温度及磁性能的影响,指出了高品质取向硅钢成分控制的发展方向。     

低碳钢板镀铅层在电阻点焊过程中的行为

本文研讨了镀铅钢板电阻点焊时,镀铅层的变化和它对接头性能的影响。试验结果表明,镀铅使焊接区的电流密度下降,析热量减少;焊后镀铅以片状或以“膜”的形式残留,在接头中这些均对接头的拉剪强度有影响。当采用大电流、短时间的强规范焊接时,能显著降低这种影响。     

初次再结晶组织和渗氮量对低温渗氮取向硅钢二次再结晶行为的影响

通过控制初次再结晶工艺获得尺寸不同的低温渗氮取向硅钢初次再结晶组织,研究初次晶粒尺寸对二次再结晶行为和磁性能的影响,探索初次晶粒尺寸过大条件下合适的渗氮量,并分析初次再结晶组织中{411}〈148〉织构对二次再结晶行为的影响。结果表明:随着初次晶粒尺寸由10μm升高至15μm,二次再结晶温度升高,Goss织构更加锋锐,成品磁性能提高,当初次晶粒尺寸为28μm时,合适的渗氮量约为6×10-4。初次再结晶组织中{411}〈148〉取向晶粒生长能力更强,极易粗化,阻碍二次晶粒的异常长大,同时{411}〈148〉与黄铜晶粒之间为大于45°的低迁移率晶界,对黄铜晶粒异常长大的阻碍作用更为显著。     

异步轧制对硅钢极薄带三次再结晶的影响

分别采用同步和异步轧制将成品工业取向硅钢板冷轧到0.045～0.10mm,然后在纯氢气热处理炉中进行三次再结晶高温退火,研究轧制工艺参数对取向硅钢极薄带织构和磁性能的影响,探索异步轧制对硅钢极薄带三次再结晶行为影响机理.结果表明,采用异步轧制取向硅钢极薄带的磁性能优于同步轧制的;硅钢极薄带厚度愈薄,磁性能愈好,三次再结晶发展得越完善.     

Effect of Electropulsing on Recrystallization and Mechanical Properties of Silicon Steel Strips

Electropulsing-induced recrystallization and its effect on mechanical properties of oriented silicon steel strips (Fe-3.0%Si) were studied by optical microscopy, scanning electron microscopy and electron back-scatter diffraction. The results indicated that electropulsing accelerated recrystallization, and decreased the temperature of recrystallization. Electropulsing favors refinement of the grain structure of the alloy. Effects of electropulsing on strength and elongation of the alloy were discussed from the point view of dislocation dynamics, microstructural changes, and electropulsing kinetics.     

Influence of primary annealing on Goss development in grain oriented silicon steels

Abstract

Two different primary annealing conditions (continuous heating and discontinuous heating) on conventional oriented silicon steel were employed, and the evolution of microstructure and Goss frequency, as well as orientations of Goss neighbourhood from recovery to secondary recrystallisation, was investigated by means of optical microscopy and advanced electron backscatter diffraction (EBSD) technique. It could be concluded that high Goss frequency before secondary recrystallisation possibly did not contribute to sharp Goss orientation, even excellent magnetic property and that no grains with less deviation from ideal Goss first began to grow. As for coincidence site lattice (CSL) grain boundary and high energy grain boundary theories, the latter can explain the development of Goss due to its high frequency compared with CSL boundary of low frequency.     

Effects of Primary Annealing Condition on Recrystallization Texture in a Grain Oriented Silicon Steel

The recrystallization texture in grain oriented silicon steel sheets, which were annealed at different primary annealingtemperatures with and without an electric field, was investigated. An automated electron backscattered diffraction(EBSD) technique was used to analyze the recrystallization texture. It was found that recovery and application ofelectric field in primary annealing lead to an increase of {001} component and a decrease of {111} component afterannealing at 900℃. The development of recrystallization texture can be explained in terms of the effects of electricfield and primary annealing temperature on recovery.