Abstract: As heat conductivity of austenite heat resistant stainless steel 310S (%:0.05C,24.5Cr,19.3Ni)is poor,only 0.029 × 4.18 J/(cm · ℃)at 100℃,the surface longitudinal cracks with wide 0.1～10 mm and depth 1～20 mm of 200 mm ×(950～2150)mm casting slab easy produce.By using mold flux ST-SP/310 with lower melting point-1085 ℃ to replace mold fux ST-SP/810 with higher melting point-1120℃,decreasing broad face and narrow face cooling; water rate respectively to 4300 L/min and 430 L/min from original 4500 L/min and 460 L/min,decreasings liquid superheating extent to 20~35℃ from 30~45℃ and lowering casting speed to 0.80～0.90 m/min from 0.95 m/min,the quality of cast slab obviously improves to avoid the occurrence of surface longitudinal crack.

Key words: Heat Resistant Stainless Steel 310S, Concasting Slab, Longitudinal Crack, Process Improvement

摘要： 310S奥氏体耐热不锈钢(%:0.05C、24.5Cr、19.3Ni)导热性差[100℃导热系数0.029×4.18J/(cm·℃)],200 mm×(950～2 150)mm连铸板坯易产生纵裂纹(宽0.1～10 mm,深1～20 mm)。通过采用熔点1 085℃的保护渣(ST-SP/310)替代熔点1 120℃的保护渣(ST-SP/810),结晶器宽面和窄面的冷却水流量分别从4 500 L/min和460 L/min降至4 300 L/min和430 L/min,钢水过热度从30～45℃降至20～35℃,拉速从0.95m/min降至0.80～0.90 m/min,铸坯质量明显改善,消除了表面纵裂。

关键词: 310S耐热不锈钢, 连铸板坯, 纵裂, 工艺改进