Determining the effect of grain size and maximum induction upon coercive field of electrical steels

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:323

Article

Gomes Landgraf, Fernando Jose^1,2  Filipini da Silveira, Joao Ricardo¹  Rodrigues-Jr, Daniel¹ 

[1] Univ Sao Paulo, Escola Politecn, Dept Mat & Met Engn, BR-05508030 Sao Paulo, Brazil

[2] Inst Technol Res IPT, BR-05508901 Sao Paulo, Brazil

关键词: Coercive field;    Grain size;    Maximum induction;    Distribution breadth;    Crystallographic texture;   

DOI  :  10.1016/j.jmmm.2011.03.034

来源: Elsevier

【 摘 要 】

Although theoretical models have already been proposed, experimental data is still lacking to quantify the influence of grain size upon coercivity of electrical steels. Some authors consider a linear inverse proportionality, while others suggest a square root inverse proportionality. Results also differ with regard to the slope of the reciprocal of grain size-coercive field relation for a given material. This paper discusses two aspects of the problem: the maximum induction used for determining coercive force and the possible effect of lurking variables such as the grain size distribution breadth and crystallographic texture. Electrical steel sheets containing 0.7% Si, 0.3% Al and 24 ppm C were cold-rolled and annealed in order to produce different grain sizes (ranging from 20 to 150 mu m). Coercive field was measured along the rolling direction and found to depend linearly on reciprocal of grain size with a slope of approximately 0.9 (A/m)mm at 1.0 T induction. A general relation for coercive field as a function of grain size and maximum induction was established, yielding an average absolute error below 4%. Through measurement of B(50) and image analysis of micrographs, the effects of crystallographic texture and grain size distribution breadth were qualitatively discussed. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

Free