【摘要】：硅含量在6.5%左右的高硅硅鋼片具有十分優(yōu)異的磁性能：磁導(dǎo)率高、鐵損低、磁致伸縮小,可以實(shí)現(xiàn)低能耗、低噪聲,是一類節(jié)能環(huán)保的軟磁材料。但是6.5%硅鋼是一種脆性材料,不可軋制加工,因此不能用傳統(tǒng)軋制的工藝來(lái)制備。目前只有日本采用CVD法實(shí)現(xiàn)了工業(yè)化生產(chǎn),但其成本高昂。近十幾年來(lái),由于粉末冶金法成本低,成為人們制備高硅硅鋼片的又一途徑。 本文采用不同粉體原料,分別采用粉末軋制法和塊體軋制法,探索了用粉末冶金法制備高硅硅鋼片的工藝條件,研究了影響軋制工藝和硅鋼磁性能的因素,得出了比較適宜的制備工藝,制得了性能較好的高硅硅鋼片。 首先,以鐵粉為對(duì)象,采用有限元法對(duì)粉體軋制過(guò)程進(jìn)行了模擬和實(shí)驗(yàn)。模擬和實(shí)驗(yàn)結(jié)果表明,采用粉體軋制時(shí),上下表面由于受力情況與內(nèi)部不同,多呈現(xiàn)疏松的結(jié)構(gòu)。粉體軋制時(shí),粉體的流動(dòng)性和輥縫是影響軋制帶材的重要因素。輥縫是影響帶材密度的主要因素,高流動(dòng)性的粉體軋制得到的帶材較為致密。當(dāng)原料中存在流動(dòng)性差的另一硅相時(shí),流動(dòng)性差的硅相易損失,使帶材元素含量偏離配比。 純鐵在1400℃以下時(shí)難以燒結(jié)致密化。鐵硅之間的擴(kuò)散反應(yīng)與粉體粒度和溫度密切相關(guān),從而影響燒結(jié)體的軋制能力,最終影響硅鋼的性能。當(dāng)硅粉粒度適當(dāng)時(shí),經(jīng)初次熱處理后,得到既無(wú)單質(zhì)Si,又具有較好變形能力時(shí),經(jīng)二次軋制和高溫?zé)崽幚砜梢缘玫矫芏容^高、性能較好的硅鋼片。 加入少量的Sn可以提高Si與Fe的反應(yīng)能力,從而在低溫短時(shí)間內(nèi)實(shí)現(xiàn)Si與Fe的反應(yīng)。Sn的加入還可改善Fe的燒結(jié),容易得到大晶粒的Fe。含H2的氣氛對(duì)燒結(jié)硅鋼不利,易造成硅的氧化。比較適宜的燒結(jié)氣氛為Ar。 采用超細(xì)硅粉和鐵粉混合后,經(jīng)500-1000℃SPS處理后得到的塊體材料具有變形能力,可以通過(guò)軋制得到厚度為0.3-0.4mmm的片材,但是經(jīng)高溫?zé)崽幚淼玫降墓桎撈难趸瘒?yán)重,帶材致密度不高,材料的磁性能比粉末軋制法制備的材料差。 以Fe和FeSi為原料經(jīng)SPS燒結(jié)可制備出具有軋制能力的硅鋼錠。FeSi原料的顆粒粒度、SPS溫度、壓力對(duì)Fe和FeSi顆粒之間的擴(kuò)散反應(yīng)有影響,從而影響最終產(chǎn)物的物相顯微結(jié)構(gòu)。由粗顆粒原料燒結(jié)的塊體具有良好的延展性,表現(xiàn)為韌性斷裂；隨粒度的減小、燒結(jié)溫度的升高,燒結(jié)試樣延展性變差,逐漸變成脆性斷裂。制備致密且具有良好延展性的硅鋼錠的適宜工藝條件為：粗FeSi顆粒在1100℃以下溫度燒結(jié)、燒結(jié)壓力50MPa。 以具有可軋能力且密度高的硅鋼塊體為原料,經(jīng)軋制減薄和退火處理,可以制備出性能較好的高硅硅鋼片。其磁性能為飽和磁化強(qiáng)度17740Gs,矯頑力3.670e。其飽和磁化強(qiáng)度與由Fe和Si混合后再軋制燒結(jié)制備的硅鋼相當(dāng),但矯頑力約降低9倍。
[Abstract]:High silicon steel sheet with about 6.5% silicon content has excellent magnetic properties, such as high permeability, low iron loss, low magnetostriction, low energy consumption and low noise, so it is a kind of soft magnetic material which can save energy and protect environment. However, 6.5% silicon steel is a brittle material and cannot be rolled, so it can not be prepared by traditional rolling technology. At present, only Japan uses CVD method to realize industrial production, but its cost is high. In recent years, powder metallurgy has become another way to fabricate high silicon steel due to its low cost. In this paper, using different powder raw materials, powder rolling method and bulk rolling method, the technological conditions of preparing high silicon steel sheet by powder metallurgy method are explored, and the factors influencing the rolling process and magnetic properties of silicon steel are studied. The more suitable preparation process was obtained and the high silicon steel sheet with better performance was prepared. Firstly, the rolling process of iron powder was simulated and tested by finite element method. The simulation and experimental results show that when the powder is rolled, the upper and lower surfaces show loose structure due to the difference between the internal and the loading conditions. The fluidity of powder and the roll gap are the important factors affecting the rolling strip. Roll gap is the main factor affecting strip density, and the strip produced by high fluidity powder rolling is compact. When there is another silicon phase with poor fluidity in the raw material, the silicon phase with poor fluidity is easy to lose, which makes the element content of strip deviate from the ratio. It is difficult to densify pure iron when it is below 1400 鈩，

本文編號(hào)：2156141