(1. 北京科技大學(xué) 鋼鐵冶金新技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，北京 100083；
2. 北京科技大學(xué) 冶金與生態(tài)工程學(xué)院，北京 100083；
3. 北京科技大學(xué) 材料科學(xué)與工程學(xué)院，北京 100083)
摘 要: 采用高溫實(shí)驗(yàn)和光學(xué)顯微鏡、掃描電子顯微鏡等研究Mg含量對1 873 K下Ti-Mg復(fù)合脫氧后鑄錠樣品中夾雜物組成、大小分布以及實(shí)驗(yàn)鋼中晶內(nèi)鐵素體形核的影響。結(jié)果表明：當(dāng)Mg含量(質(zhì)量分?jǐn)?shù))為0.001 5%~0.002 6%時，實(shí)驗(yàn)鋼中夾雜物的分布最為細(xì)小彌散，晶內(nèi)鐵素體形核效果較好。當(dāng)奧氏體化溫度為1 200 ℃時，鋼中晶內(nèi)鐵素體的比例較高，有利于晶內(nèi)鐵素體形核的最佳奧氏體晶粒大小為120 μm左右。
關(guān)鍵字: Ti-Mg合金；脫氧；夾雜物；晶內(nèi)鐵素體；奧氏體晶粒
（1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China;
3. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The effects of Mg content on the composition, size distribution of inclusions and microstructure of ingot samples deoxided by Ti-Mg at 1 873 K were investigated by high temperature tests, SEM-EDS and optical microscopy (OM). The results show that when the Mg content (mass fraction) varies from 0.001 5% to 0.002 6%, the inclusions in experimental steel are fine-distributed, and the effectiveness of intragranular ferrite nucleation is better. At austenitizing temperature of 1 200 ℃, the proportion of intragranular ferrite in steel is higher, and the optimized austenite grain size that is beneficial to intragranular ferrite nucleation is about 120 μm.
Key words: Ti-Mg alloy; deoxidation; inclusions; intragranular ferrite; austenite grain
