取向硅钢中{114}<418>织构对二次再结晶时晶粒异常长大的影响

EFFECT OF {114}<418> TEXTURE ON ABNORMAL GROWTH DURING SECONDARY RECRYSTALLIZATION IN GRAIN-ORIENTED STEEL

运用EBSD技术观察Hi B钢在大压下率冷轧条件下薄规格样品的二次再结晶行为,从而研究薄规格样品二次再结晶难以发生的原因.通过渗氮处理添加抑制剂使二次再结晶能顺利发生,并研究渗氮量对薄规格样品二次再结晶的影响,以及{114}<418>织构对黄铜与Goss取向晶粒异常长大的影响.结果表明,在二次再结晶退火时,相对于其它取向的晶粒,两侧表层的{114}<418>取向附近的晶粒具有明显的长大优势,并向中心层生长,如果样品表层抑制剂强度不足,其容易长大到样品的中心层吞并掉二次再结晶的核心而不利于二次再结晶的发生,经渗氮补充抑制剂后能有效抑制表层晶粒的长大,从而有利于二次再结晶的发生和磁性能的提高;在二次再结晶初期,{114}<418>取向附近的晶粒容易保留在发生异常长大的偏转Goss取向晶粒和黄铜取向晶粒的中心处并形成岛晶而不利于它们的异常长大,但该取向的晶粒对Goss取向晶粒异常长大的影响较小.

To find out the reason of poor secondary recrystallization behavior in thin-gauged gain-oriented steel, EBSD technique is applied to reveal the grain growth behavior of thin-gauged steel processed by HiB steel method under high cold-rolling reduction. Nitriding treatment with different times is conducted to ensure the occurrence of secondary recrystallization in thin-gauged grain-oriented steel and to determine the effect of nitrogen content. Attention is put on the influence of { 114} 〈418〉 texture on the abnormal growth of Brass and Goss grains. Results show that, at initial stage of secondary recrystallization, {114}〈418〉 grains in the surface region of sheets possess obvious growth advantage than the other oriented grains. If these grains in the surface region grew to the central layer of sheet and swallowed the nucleus of secondary recrystallization, abnormal growth could not occur. In contrast, reinforcing the inhibitors at surface region of sheet by nitriding treatment will avoid the excessive growth of surface grains and therefore improve magnetic properties of steel significantly. The {114} 〈418〉 grains are adverse to the abnormal growth of Brass-oriented and scattered Goss grains in way of island grains, but their effeet on the abnormal growth of Goss grains is weaker.