Abstract: The Al in non-magnetic steel 20Mn23Al2V (/% ： 0. 14 ~ 0. 20C, ≤0. 50Si, 21. 5 ~ 25. 0Mn, 1. 50 ~ 2. 50Al, 0. 04 ~0. 10V)- [Al] easily reacts with SiO2 in mold powder- (SiO₂) led to modification of mold powder and the liquidus temperature of non-magnetic steel is lower because of higher alloy elements content, therefore the mold powder with low basicity, low A12O3 content and low melting temperature is required. Three kinds of mold powder (/% ： 20. 2 ~ 24.4CaO, 35. 3 ~40.0SiO₂,2. 2 ~ 4. 1 Al₂O₃,3. 0 ~5. 0B₂O₃) with low basicity (0. 55 ~0. 61) and low melting temperature (904 ~ 1 015 ℃) have been designed. The test results by 200 mm x 1 260 mm slab casting with 25 t tundish show that the mold powder for non-magnetic steel 20Mn23Al2V with 5.0% B₂O₃, basicity 0.50 ~0. 60, melting temperature 1 010 °C and viscosity 0. 215 Pa·s and in casting speed 0. 60 ~ 0. 65 in/min is optimum to satisfy the requirement of casting process.

摘要： 浇铸过程无磁钢20Mn23A12V(/%:0.14~0.20C、≤0.50Si、21.5~25.0 Mn、1.50~2.50Al、0.04~0.10V)中的Al-[Al]易与保护渣中的SiO₂-(SiO₂)反应,导致结晶器保护渣变性,要求低碱度、低Al₂O₃的保护渣;并且该钢合金元素含量高,液相线温度低,要求低熔化温度的保护渣。设计了3种低碱度(0.55~0.61)、低熔化温度(904~1 015℃)的结晶器保护渣(/%:20.2~24.4CaO、35.3~40.0SiO₂、2.2~4.1Al₂O₃、3.0~5.0B₂O₃),经25 t中间包,200 mm×1 260 mm板坯连铸试验。结果表明,5.0%B₂O₃,碱度0.50~0.60、熔化温度1 010℃、粘度0.215Pa·s的无磁钢20Mn23Al2V保护渣在0.60~0.65 m/min拉速下能较好的满足连铸工艺要求。 

关键词: 高铝奥氏体无磁钢20Mn23Al2V, 板坯连铸, 结晶器保护渣