本文關(guān)鍵詞： 取向硅鋼 數(shù)值模擬 滲氮 動力學 擴散　出處：《金屬學報》2017年06期 　論文類型：期刊論文

【摘要】：通過在實驗室模擬取向硅鋼的滲氮生產(chǎn)工序,實測了不同滲氮時間下的滲氮量,并通過EPMA、FESEM等觀察了滲氮后氧化層的變化、N在硅鋼帶厚度方向的濃度梯度。根據(jù)實測的組織形貌和滲氮動力學特點,首次建立了針對取向硅鋼的滲氮動力學模型,并成功地進行了數(shù)值模擬計算。研究結(jié)果表明:(1)取向硅鋼帶的平均N含量在滲氮初期增加緩慢,之后逐漸加快,直至90 s時滲氮速率達到最大值之后保持恒定;在750℃滲氮2 min時間內(nèi),在近表面0.04 mm范圍內(nèi)存在顯著的N濃度梯度;(2)脫碳退火后,取向硅鋼的氧化層主要為層狀氧化物,滲氮時氧化層被H2還原,層狀氧化物轉(zhuǎn)變?yōu)榍驙?氧化層的變化對滲氮動力學影響顯著;(3)分析了N由氣相穿過表面氧化層至Fe基體的傳質(zhì)系數(shù)所遵循的可能模型,發(fā)現(xiàn)只有當傳質(zhì)系數(shù)遵循氧化層還原動力學模型時,即Avrami函數(shù)模型f=A(1-exp(-ktn)),計算結(jié)果才能與實測的滲氮動力學特征高度吻合。
[Abstract]:By simulating the nitriding process of oriented silicon steel in laboratory, the nitriding amount under different nitriding time was measured. The concentration gradient of the oxide layer in the direction of the thickness of silicon steel strip was observed by EPMA-FESEM. According to the measured microstructure and nitriding kinetics, the nitriding kinetics model for oriented silicon steel was established for the first time. The numerical simulation results show that the average N content increases slowly at the beginning of nitriding, then accelerates gradually, until the nitriding rate reaches the maximum at 90 s and keeps constant. During nitriding at 750 鈩，

本文編號：1553895