摘要
将低牌号无取向电工钢的原始铸坯采用不同的工艺轧制得到5组样品,在H_2气氛下进行相变退火处理,使其发生α→γ→α相变,采用EBSD、XRD和磁性能测量技术确定了不同轧制工艺对低牌号无取向电工钢相变退火组织、织构与磁性能的影响。结果表明,与常规再结晶退火处理相比,相变退火处理可显著粗化晶粒降低成品板铁损;相变过程中存在织构遗传现象,相比于热轧-冷轧工艺,直接冷轧工艺相变退火后更有利于获得{100}织构,并显著改善成品板的磁性能;低温热轧比高温热轧能保留更多的{100}取向晶粒,相变退火后成品板中的非{111}取向晶粒增多,并提高了成品板的磁性能;此外,工业板中P和Al元素的偏聚或氧化对相变退火后成品板的组织、织构与磁性能有不利影响。
Non-oriented electrical steel sheets are important metallic functional materials for the iron cores in transformers and electrical motors, which require the performance characteristics of low iron loss and high magnetic induction. The magnetic properties of electrical steel critically depend on the microstructure and the occurring texture components. In addition, alloy elements can affect the magnetic properties by altering the electrical resistivity, microstructure and texture. At present, the quality of commercial non-oriented electrical steels are mainly optimized by the control of deformation, recrystallization parameters and chemical composition. And the microstructure, texture and magnetic properties are significantly influenced by the rolling process before recrystallization annealing. The favorite {100} texture in such condition takes at maximum only about 20% in volume fraction. In contrast, phase transformation combined with deformation can lead to nearly 80% volume fraction of {100}-oriented grains. In this work, the influence of rolling process on the microstructure, texture and magnetic properties of low grades non-oriented electrical steel after phase transformation annealing was studied by means of EBSD, XRD and magnetism measuring techniques. The starting material is a columnar-grained industrial low grades electrical steel cast slab. Five different initial microstructures are obtained after different rolling processes, the α→γ→α phase transformation annealing of samples is conducted in a tube furnace under H+2 atmosphere.The results show that phase transformation annealing can significantly coarsen grains and reduce the iron loss of non-oriented electrical steels compared with traditional recrystallization annealing. And the phase transformation texture is influenced by texture memory. Compared with hot rolling-cold rolling process, more {100}-oriented grains are obtained and the magnetic properties of non-oriented electrical steels are improved significantly after phase transformation in the directly cold rolling process. The proportion of non-{111} oriented grains increases and more initial {100}-oriented grains are retained after phase transformation in the process with lower hot rolling temperature, which improve the magnetic properties of final sample. In addition, the presence of P and Al elements in commercial electrical steels may affect the microstructure, texture and magnetic properties of non-oriented electrical steels due to segregation and oxidation after phase transformation.
作者
顾晨
杨平
毛卫民
GU Chen;YANG Ping;MAO Weimin(School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第2期181-190,共10页
Acta Metallurgica Sinica
基金
国家自然科学基金项目No.51771024~~
关键词
无取向电工钢
轧制工艺
织构遗传
相变
化学元素
non-oriented electrical steel
rolling process
texture memory
phase transformation
chemical element
作者简介
顾晨,女,1993年生,硕士生;通讯作者::杨平,yangp@mater.ustb.edu.cn,主要从事晶体材料的各向异性原理及织构控制技术方面的研究.
