凝固組織的影響
(西北工業(yè)大學(xué) 凝固技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，西安 710072)
摘 要: 研究真空自耗電弧熔煉(VAR)條件下熔煉電流對(duì)Ti-10V-2Fe-3Al合金凝固組織的影響,分析VAR熔煉中熔池內(nèi)部的對(duì)流類(lèi)型，基于安培定理，建立VAR熔煉條件下熔池中的洛侖茲力與電流、磁場(chǎng)及鑄錠半徑的關(guān)系。結(jié)果表明：熔煉電流較低時(shí)，浮力的影響占據(jù)主要地位，加速熱量的散失，鑄錠中組織細(xì)小；隨著熔煉電流變大，熔池中電磁力(洛倫茲力)的影響逐漸占據(jù)主要地位，將表面的熱量帶入熔池內(nèi)部，增大了溫度梯度，使鑄錠組織變得粗大
關(guān)鍵字: Ti-10V-2Fe-3Al；凝固組織；真空自耗電弧熔煉；熔煉電流；洛侖茲力；浮力
（State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The influence of remelting current on the solidification macrostructure of Ti-10V-2Fe-3Al under vacuum arc remelting was investigated. Based on the Ampere–Maxwell equation, the relationships among the radius of the pool, intensity of magnetic field and electromagnetic (Lorentz) force were established. The results show that the flow is dominated by weaker buoyancy forces at low arc current, in this case, heat dissipation accelerate, the solidification microstructure becomes finer. With increasing arc current, the liquid metal flow is electromagnetically driven by Lorentz force, the heat is taken inside from superstratum of the pool, the temperature gradient in the pool increases, and the solidification microstructure becomes coarser.
Key words: Ti-10V-2Fe-3Al; solidification microstructure; vacuum arc remelting; arc current; Lorentz force; buoyant force
