摘要
研究了薄板坯连铸连轧工艺的铸坯凝固组织特征和钢带的组织演变规律.通过化学相分析、微观组织分析研究发现,微细AlN粒子在薄板坯连铸过程中可沉淀析出,铸坯经20～30 min均热后AlN仅部分溶解.对AlN析出的热力学和动力学分析也证实了AlN在铸坯上沉淀析出的合理性.这些在连轧开始前原始奥氏体中析出的AlN沉淀是抑制变形奥氏体再结晶晶粒长大,细化奥氏体组织,并最终使钢带组织细化的主要原因;同时,薄板坯连铸连轧流程冷却辊道短、冷却强度大等因素也是导致薄板坯连铸连轧过程中Al镇静钢组织细化的主要原因.
The precipitation characteristics during solidification and microstructure of slab and microstructure evolution of strip during rolling for thin slab casting and rolling （TSCR） were investigated. The phase analysis and precipitation investigation found that AIN particles are precipitated during casting and dissolved little during soaking at 1130-1150 ℃ for 20-30 min. The precipitation behavior of AIN can be verified by thermodynamic and kinetics calculation. Due to the pinning of AIN on grain growth of recrystallized austenite, the austenite grain size after roll- ing can be refined. As a result, a more refined microstructure in TSCR strip than that in convetionally rolled strip is obtained. On the other hand, the powerful accelerated cooling of TSCR also plays an crucial role for refining the grain size.
出处
《钢铁》
CAS
CSCD
北大核心
2005年第12期1-9,共9页
Iron and Steel
