取向硅钢激光刻痕工艺参数优化及相关原理分析

对120牌号取向硅钢成品板进行激光刻痕,研究工作电流、激光频率、刻痕速率等参数对细化磁畴及铁损值的影响规律。在此基础上分析了不同工艺下的刻痕表面形貌及磁畴细化的程度。结果表明,该样品优化的刻痕参数:工作电流12A、激光频率3 500Hz、刻痕速率800mm/s,该参数下P1.7可降低9.45%。不同参数下样品表面刻痕形貌差异较大,刻痕蚀点刚好连续时磁畴细化效果最好;激光刻痕后,磁畴宽度明显减小,但显著细化区分布很不均匀。     

基于磁畴结构交互作用的激光刻痕取向硅钢磁致伸缩系数计算

基于取向硅钢磁畴结构与磁致伸缩系数的定量关系,综合考虑激光刻痕参数和取向偏差角对应力封闭畴与横向畴2种90°磁畴结构的影响,提出反映刻痕参数与取向偏差角交互作用的磁致伸缩系数计算模型。计算结果表明,取向偏差角的大小决定了激光刻痕条件下磁致伸缩行为是由横向畴还是应力封闭畴主导;激光刻痕产生的局部封闭畴与杂散磁场可降低取向偏差角引起的磁致伸缩系数。刻痕能量密度和刻痕线间距等参数对取向硅钢磁致伸缩系数影响的计算结果与实测结果相吻合,表明本工作所提模型可为降低激光刻痕取向硅钢的噪音提供理论基础。     

初始组织和磁性能对激光刻痕处理取向硅钢铁损降幅的影响

以27AG100高磁感取向硅钢为研究对象,通过激光刻痕试验研究了初始组织和磁性能对其铁损降幅的影响,并分析了不同初始状态下磁畴细化程度.结果表明:27 AG100取向硅钢刻痕理论铁损降幅最高可达7％,且刻痕前磁性能越接近平衡点,铁损降幅越有限.同时,二次再结晶晶粒平均尺寸大、均匀度好的组织有利于磁畴细化,最高铁损降幅可...     

取向硅钢激光刻痕对绝缘层的影响及刻痕耐热性分析

研究了不同输入电流下激光刻痕对取向硅钢表面绝缘涂层的影响,分析了刻痕宽度、刻痕深度和磁性能随电流的变化规律及刻痕对绝缘涂层的破坏程度,并对刻痕后的取向硅钢样品进行退火,研究刻痕后磁畴粗化规律,对激光刻痕的耐热性进行分析。结果表明:随着电流的增大,刻痕的宽度和深度增大,刻痕对绝缘涂层的损伤严重。激光刻痕样品在500℃以上的温度下进行去应力退火,磁畴开始粗化,铁损较刻痕后升高。确定了磁畴粗化定量关系。随着退火温度升高,磁畴宽度增大,铁损升高的幅度增大。     

高磁感取向硅钢表面处理对铁芯损耗的影响

为了进一步降低趋向硅钢铁损,研究了表面处理对取向硅钢铁芯损耗的影响,采用铁损分离的方法研究了磁滞损耗和异常涡流的变化规律。结果表明:取向硅钢经抛光处理,激光刻痕和PVD制备的高张力涂层复合作用铁芯损耗下降22%以上,其中表面抛光使得磁滞损耗下降28%左右,但异常涡流损耗上升15%左右,进一步采用刻痕和陶瓷涂层细化磁畴工艺处理,磁滞损耗上升5%,异常涡流损耗下降40%左右。     

激光刻痕对高磁感取向硅钢板耐蚀性的影响

通过扫描电镜(SEM)和能谱仪(EDS)对激光刻痕后高磁感取向硅钢表面进行形貌观察和化学成分分析，并采用硫酸铜点滴试验、加速腐蚀试验(交变湿热试验及动态接触湿热试验)研究了激光刻痕对取向硅钢耐蚀性的影响。结果发现：激光刻痕对取向硅钢表面涂层厚度均匀性和平整性造成破坏，使取向硅钢基体出现裸露的情况，耐蚀性大幅降低。     

降低铁损的激光处理实验

采用ＪＧ－２Ａ激光器对３５Ｚ１４５硅钢材料进行照射实验，阐述了激光处理提高硅钢晶粒取向，降低铁损的技术。     

压缩机电机用无取向硅钢二次退火组织和磁性能

对不同成分体系的无取向硅钢进行相同工艺的二次退火试验，研究了不同成分体系的无取向硅钢二次退火后组织和磁性能的演变规律。结果表明，二次退火能进一步增大无取向硅钢的铁素体晶粒尺寸，提升磁性能。二次退火后无取向硅钢磁性能的提升潜力与无取向硅钢的成分体系有关，与成品退火温度无关。其中，高Al成分体系的无取向硅钢二次退火后铁素体晶粒更易长大，平均晶粒尺寸达到159μm,铁损降幅最大，达到了1.14 W/kg,磁性能最优；除此之外，二次退火还能显著提升无取向硅钢在低磁场强度下的磁感应强度，进而提高无取向硅钢在低磁场强度下的磁导率；在电机工作磁感0.5～1.5 T区间内，二次退火后无取向硅钢的磁导率明显高于二次退火前。针对需要二次退火的压缩机电机铁芯，采用高Al成分体系的无取向硅钢有助于提升电机性能。     

冷轧压下量对无取向硅钢组织和性能的影响

研究了冷轧压下量对一种含硅3%无取向硅钢的组织和性能的影响。结果表明,随着冷轧压下量的降低,无取向硅钢的晶粒变粗大,晶粒均匀度较差,织构明显改善,磁感应强度有所提高;冷轧压下量对无取向硅钢铁损的影响不大。     

氮化硅张力涂层对取向硅钢性能的影响

采用反应磁控溅射技术在取向硅钢片表面制备了氮化硅(Si3N4)张力涂层.通过实验研究反应磁控溅射时间、高温退火温度和实验气氛对硅钢铁损以及涂层附着性的影响.研究表明,反应磁控溅射技术在硅钢表面溅射氮化硅张力涂层可有效的降低硅钢的铁损,且各种工艺条件对硅钢的铁损和涂层的附着性影响很大.在氮气和氩气气氛中,经过5min反应磁控溅射氮化硅,然后在氢气和氮气的气氛中,820℃下进行高温退火时,取向硅钢的铁损可降低18%.     

Effects of uniaxial stress on the magnetic properties of laser scribed grain oriented 3.2% Si steel

Effects of laser scribing on the magnetic properties of commercial grain-oriented 3.2% Si steels were investigated. Laser scribing was shown to play a significant role in reducing the core loss of tension-coated grainoriented (GO) Si steels. The reduction ratio of the core loss was dependent on the applied strees conditions and orientation of magnetic domains. Longitudinal tensile stress contributes to the increase of magnetic flux density. Laser scribing contributes to the redistribution of magnetic domains and creates 90° magnetic domains. GO Si steel is described by negative values of magnetostriction. Laser scribing results in magnetostriction positive values whereas application of tensile stress causes negative magnetostriction.     

STUDY ON REDUCING THE CORE LOSS OF GRAIN ORIENTED SILICON STEEL AND IMPROVING ITS AGING PROPERTY BY LASER NITRIDING TECHNIQUE IN ATMOSPHERIC AMBIENT

1. IntroductionSince the needsofelectric pow erindustry developm entand forlack ofenergy source, to m anufac-ture softm agnetic m aterialsofquality hasalw aysbeen a very im portanttask.The invention ofgrain ori-ented silicon steelbroughtgreatbenefitto sav…     

New process for production of ultra-thin grain oriented silicon steel

The Hi-B silicon steels were cold rolled by cross shear rolling (CSR) with different mismatch speed ratio(MSR)s and conventional rolling(CR) respectively, followed by primary recrystallization annealing. The effects of MSR and annealing temperature on magnetic properties of ultra-thin grain oriented silicon steel were analyzed. Experimental results show that, with the increase of MSR, the magnetic properties can be remarkably improved. The higher the annealing temperature is, the higher the magnetic induction and the lower the iron loss in ultra-thin silicon steel is.     

Future Prospects for Grain-Oriented Silicon Steels

Revolutionary developments for electrical steels in the 1980’s show that before the mid-point of the decade, 3% silicon steel products underwent a dramatic development in core loss improvements within a period of about four years. By the mid-80’s, higher performing silicon steels were available with 60 Hz 1.7T losses improved by about 30% to less than 500 mwpp. These improvements arose from the utilization of cleaner steels, lighter gages, higher permeabilities (B₈) and domain refinement techniques such as laser scribing, grain size control and coatings. The evolution of amorphous magnetic materials of suitable B_s and extremely low losses places more competitive pressure on grain-oriented silicon steel producers to further improve their product. By the end of the decade, it might be possible to commercially produce a high technology silicon steel product with performance rivaling that of amorphous steels.     

Magnetic properties of high-efficiency core materials NC-M3 and NC-M4

High-efficiency core materials—New Core NC-M3 and NC-M4— with very low core loss and high permeability have been developed to improve the magnetic properties of conventional magnetic lamination steels. The magnetically favorable crystalline textures are enhanced through the addition of Mn and Sn to low-silicon steel. By adding Mn, particularly more than ~ 1.0 wt.%, to low- silicon steel, a decrease in (111) plane crystals and an increase in (110) and (100) plane crystals are achieved. Moreover, by adding Sn to low- silicon steel containing Mn, the decrease in (111) plane crystals and the increase in (110) plane crystals are more significant. The most suitable amount for the addition of Sn is ~ 0.1 wt.%, because excessive Sn content prevents normal grain growth in steels and makes magnetic properties, particularly core loss, inferior. Typical magnetic properties of NC- M3 (0.47- mm thickness) are 1.70 W/lb in W_15/60 and 3000 Gauss/Oe in μ15/60, and those of NC- M4 (0.47- mm thickness) are 1.57 W/lb in W_15/60 and 3000 Gauss/Oe in μ15/60. The lower core losses are attained mainly by reducing hysteresis loss. The superior magnetic properties of NC- M4 compared to NC- M3 are due to the fact that the steel is cleaner and has undergone sufficient hot band annealing during manufacturing.     

Effects of laser irradiation on iron loss reduction for Fe–3%Si grain-oriented silicon steel

The effects of laser irradiation on iron loss reduction for Fe–3%Si grain-oriented silicon steel sheet were investigated. The local tensile residual stress states near the laser irradiated cavity lines were observed by using the new X-ray stress measurement method for a single crystal. Although the higher laser power induced the larger tensile residual stresses, the minimum iron loss was obtained at the medium tensile residual stress conditions of about 100–200 MPa. The increase of Vickers hardness was observed with increasing laser power, which was the mark of the plastic deformations induced by the laser irradiation. The tensile residual stress reduces eddy current loss and the plastic deformation increases hysteresis loss of the material. The total iron loss is determined by the balance of these two effects of laser irradiation.     

基于Stoney公式适用性分析——取向硅钢绝缘涂层张应力的计算

目的改善涂层张应力状态,进而提升取向硅钢的电磁性能。方法用扫描电镜、辉光光谱仪分析了添加磷酸盐的胶体二氧化硅绝缘涂层的厚度和微观结构,采用静态拉伸试验得到了取向硅钢沿不同位向的力学特性。在此基础上,根据取向硅钢各向异性的特点和绝缘涂层的实际状态,用Stoney公式对取向硅钢涂层应力的适用性进行了讨论。结果取向硅钢的各向异性不满足Stoney公式的适用条件,实际测试的取向硅钢的力学性能结果表明,取向硅钢符合正交对称各向异性材料的一般规律,据此给出了涂层对取向硅钢产生的张应力的计算公式,利用该公式对不同涂覆工艺条件下的胶体二氧化硅绝缘涂层的张应力进行了计算,涂层厚度在1～2μm范围内,双面张应力的计算值为4～11 MPa。结论文中张应力的计算公式不仅适用于取向硅钢,同样适用于其他基体为各向异性的类似情况。通过张应力的计算可知,涂层厚度与张应力呈正相关,张应力的增大将会促使取向硅钢的铁损降低。因此,开发大张力的绝缘涂层,是进一步改善取向硅钢磁性能的有效途径之一。     

退火工艺对平整轧制后50W800无取向硅钢磁性能的影响

为提高50W800无取向硅钢的板形,需要对再结晶退火后的硅钢进行平整轧制,在平整后会出现硅钢片磁性能下降现象。对平整轧制后的50W800无取向硅钢进行400~800 ℃的去应力退火,利用单片测量法测量其铁损和磁感应强度,并用EBSD技术对组织织构进行分析。结果表明,经过平整轧制后,50W800无取向硅钢小角度晶界增加,但晶粒不均匀性会导致磁性能下降;采用700 ℃×2 min去应力退火后,50W800无取向硅钢磁性能得到较好的改善。EBSD技术分析发现,去应力退火能消耗大量小角度晶界,使晶界含量降低,晶粒均匀性增加,不利形变织构{111}<112>强度降低,这是50W800无取向硅钢磁性能改善的主要原因。     

稀土元素Ce对取向硅钢热轧钢带组织和织构的影响

对2250 mm热轧生产线生产的取向硅钢热轧钢带的合金体系进行了设计,制定了合理的加热制度和热轧轧制工艺。对添加稀土元素Ce的取向硅钢铸坯和热轧钢带进行了分析,探究了稀土元素Ce对取向硅钢低倍组织、热轧织构及成品磁性能的影响。结果表明,稀土元素Ce能够细化取向硅钢连铸坯低倍组织和热轧显微组织,提高取向硅钢成品磁性能。