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。     

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.     

硅钢绝缘涂层的研究进展

本文系统介绍了取向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。无机涂层具有良好的耐热和焊接性能，但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，但其耐热性和焊接性不及无机涂层。另外，最新研究的取向硅钢表面物理气相沉积ＴｉＮ、ＣｒＮ和ＴｉＣ绝缘涂层可使硅钢获得极低的铁损，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。     

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。     

激光刻痕对取向硅钢铁损和磁畴的影响规律研究

激光刻痕是一种降低取向硅钢片铁损的有效方法。选取激光功率、扫描速度、激光频率、刻痕间距作为工艺变量,对取向硅钢片进行刻痕实验,并利用磁性能测试系统和磁畴观测仪研究了不同工艺参数对激光刻痕后取向硅钢铁损和磁畴的改善效果。结果表明,取向硅钢片的平均铁损降低率随激光功率和刻痕间距增大而先增大后减小,随激光频率和扫描速度增大而减小。经不同工艺参数刻痕后,硅钢片的磁畴宽度均有所减小,且磁畴宽度的变化规律与铁损降低率的变化规律相吻合。优化了取向硅钢片的激光刻痕工艺参数,利用此工艺刻痕后,取向硅钢片的平均铁损降低率达8%。     

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。     

宁波材料所在铁基纳米晶软磁合金研究方面取得新进展

中科院宁波材料技术与工程研究所沈宝龙课题组在前期探索发现的具有高饱和磁感应强度和良好软磁性能的FeSiBPCu合金基础上,对合金成分及纳米晶化工艺进行了进一步优化,成功研制出具有更优异性能的FeSiBPCu纳米晶软磁合金。该合金的纳米晶粒尺寸为15nm,其饱和磁感应强度达到1．8T,已接近于硅钢,矫顽力仅为1．1A／m,而铁损则远低于硅钢,在工频条件下（50Hz,1T）的铁损为0．22W／kg,分别是取向硅钢铁损（0．64w／kg）的三分之一,无取向硅钢铁损（2．0W／kg）的九分之一。     

电力变压器用高磁感取向硅钢的发展及应用

阐述了国内外高磁感取向硅钢的生产研究水平与发展趋势,包括通过提高高斯晶粒取向度、细化磁畴、涂覆张力涂层、减薄钢片厚度进一步降低铁损以及低温加热技术和短流程技术新工艺。分析高磁感取向硅钢在我国大型电力变压器上的应用情况,结果表明,发展更薄规格高磁感、低铁损、低磁致伸缩取向硅钢可为大型变压器的安全性、节能性及环保性提供有效保障。     

明胶涂层表面润湿性的研究

一、前言在感光乳剂多层涂布工艺中,不仅要求涂布液能很好地铺展在基底表面上,而且要求干燥后形成的涂层易为上层涂布液所润湿,即具有良好的向下与向上润湿性能。感光乳剂中影响其润湿性的主要组分是明胶与表面活性剂,选择合适的表面活性剂,以同时获得较好的向下与向上润湿性是涂布中的重要课题。就向下润湿而言,决定因素是涂     

取向硅钢制备工艺及其发展趋势

取向硅钢作为一种重要的铁芯材料,在电力行业中有着广泛的应用.基于生产工艺及技术特点,取向硅钢的制备工艺可以分为传统厚板坯工艺、薄板坯连铸连轧工艺及双辊薄带连铸工艺.传统的厚板坯工艺是工业生产取向硅钢的主要方法,其按加热温度又可分为板坯高温加热、板坯中温加热以及板坯低温加热工艺,其中板坯低温加热工艺具有加热温度低、能耗少...     

Measurement of rotating flux in silicon iron laminations

A method of calculating the magnitude and direction of the instantaneous flux density in a thin lamination of magnetic material is described. The technique was demonstrated by measuring the rotating flux in samples of mild steel, grain-oriented silicon iron, and at a point in the T-joint of a three-phase, three-limbed transformer core. The flux in the mild steel sample was found to rotate at a constant angular velocity and to be constant in magnitude. In the silicon iron sample, and at a point in the T-joint, the flux density varied both in angular velocity and magnitude. A large 150 Hz component of rotational flux was found to cause high localized power loss in the T-joint. The power loss was measured using the "initial rate of rise of temperature method" and was compared with the predicted rotational hysteresis loss.     

Assessment of the Stress Sensitivity of Magnetostriction in Grain-Oriented Silicon Steel

This paper describes a novel, versatile system for measuring the stress sensitivity of magnetostriction of Epstein strips of grain-oriented electrical steel, an analysis of results of measurements on several grades of commercial material, and an attempt to relate their stress sensitivity characteristics to material properties. The maximum value of peak magnetostriction under applied stress is proportional to the strip gauge for both conventional and high permeability grades of material. A model explains the contributions of retained stress and stress due to the forsterite coatings on grain-oriented silicon steel. This model can be used to correlate the thickness of the fosterite coating to its calculated coating stress. It is also possible to separate the effect of the phosphate and forsterite coatings. Both types of coating set up a longitudinal stress in the steel in proportion to their thickness.     

Superhydrophilic textured-surfaces on stainless steel substrates

Aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) is used to produce micro/nano-textured surfaces on stainless steel substrates at low temperatures for altering the wetting property of the substrates. The micro/nano-textured surfaces were characterized using scanning electron microscopy, X-ray spectroscopy, and X-ray diffraction. The wetting properties of the textured surfaces were characterized by water contact angle measurements. It was found that AIC of a-Si changes the apparent contact angles of stainless steel substrates from 90° to about 0°, measured 0.5 s after a water droplet drops on the surfaces. The study also shows that a superhydrophilic textured surface can be converted to a highly hydrophobic surface with an apparent contact angle of 145° by coating the surface with a layer of octadecyltrichlorosilane.     

冷轧压下率及初始高斯晶粒取向度对超薄取向硅钢织构演变与磁性能的影响

以不同高斯取向度的取向硅钢成品板为初始原料,采用一次冷轧法制备0.06~0.12mm厚的取向硅钢薄带。利用EBSD取向成像技术研究冷轧压下率以及初始高斯晶粒取向度对超薄取向硅钢织构演变与磁性能的影响。结果表明:随着冷轧压下率增大和厚度减小,退火后再结晶织构增强,当压下率为70%时,再结晶织构中RD∥〈001〉织构最锋锐,磁性能最佳;初始样品高斯取向度越高,制备的薄带样品磁性能越好;因此,生产高性能的取向硅钢薄带应选用初始高斯晶粒取向度较高的成品板。     

钨酸盐对无铬锌铝涂层性能的影响

为实现锌铝涂层的无铬化,利用具有缓蚀作用的钨酸盐替代部分钼酸盐在Q235A碳钢板上制备无铬锌铝涂层。通过超景深三维体式显微镜、划格法、铅笔硬度法、中性盐雾试验及电化学工作站研究了钨酸盐用量对自制无铬锌铝涂层的形貌、硬度、附着力及耐蚀性的影响。结果表明:当钨酸盐含量过低时,由于钝化膜不完整,形成"活化-钝化"电池使涂层的腐蚀速率加快,耐蚀性下降;当钨酸盐含量超过2.0%时,涂层硬度降低;当钨酸盐含量为2.0%时,涂层的综合性能最佳。     

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。     

CHEMICAL VAPOR DEPOSITION OF SILICON ONTO IRON AND STEEL SUBSTRATES: OXIDATION AND CORROSION PROPERTIES OF COATED MATERIALS

The influence of the gaseous phase composition (SiH₄ or SiCI₄ diluted with argon or hydrogen), used for chemical vapor deposition of silicon onto two different substrates (pure iron or low chromium mild steel) is investigated. Depending on the chosen process, two types of coatings are developed: either a very adherent, non-porous solid solution containing up to 6 to 7 wt. % Si, or a Fe₃Si iron silicide (14.35 wt. %). This solid solution coating considerably improves the oxidation resistance properties of steels at temperatures up to 800° C. This beneficial effect was not observed on the corrosion behavior of treated samples in sulfuric acid solutions. In contrast, the Fe₃Si iron silicide has the same outstanding corrosion resistance that the silicon-rich cast alloys have in very severe environments such as boiling concentrated sulfuric acid. But this remarkable behavior is certainly limited in other mediums by the open porosity of the coating, inherent to the chemical vapor process.