%0 Journal Article
%T 双辊薄带连铸低碳微合金钢的铸态组织
%A 王鹤松
%A 袁国
%A 曹光明
%A 王国栋
%J 东北大学学报（自然科学版）
%D 2018
%R 10.12068/j.issn.1005-3026.2018.04.009
%X 摘要 采用双辊薄带连铸技术制备了低碳微合金钢薄带，利用OM，SEM和TEM对铸态凝固组织、室温组织、析出及位错进行观察和分析.结果表明:低碳微合金钢铸带的凝固组织中二次枝晶间距约为12~15μm，相对于传统厚板坯和薄板坯连铸，铸带组织得到了明显细化.铸带的原奥氏体晶粒尺寸比较粗大，约为250~410μm，其组织由魏氏铁素体、珠光体和不规则铁素体组成.铸带组织中存在纳米级TiC析出和短棒状的渗碳体.TiC析出没有被薄带连铸的凝固过程及二次冷却过程明显抑制.铸带组织由于铸轧力及二次冷却速率不均匀导致大量位错的产生.</br>Abstract：Low-carbon microalloyed steel was produced via twin-roll strip casting in the laboratory. The solidification structure， microstructure at room temperature， precipitate and dislocation of the as-cast strip were analyzed by OM， SEM and TEM. The results showed that the secondary dendrite arm spacing of the solidification structure is in the range of 12~15μm， which is much finer than that of the slab produced by the traditional process. The prior austenite grain of the as-cast strip is quite coarse with a size range of 250~410μm. The microstructure of the as-cast strip consists of Widmanstatten ferrite， pearlite and irregular ferrite. The nano-sized TiC precipitate and rod-like cementite are observed in the as-cast structure. The TiC precipitate in the as-cast strip is not obviously suppressed by the rapid solidification rate and secondary cooling rate (cooling in air) of the twin-roll strip casting. Furthermore， a large amount of dislocations in the as-cast strip are also observed， formed by rolling force among the casting rollers and nonuniform cooling rate of the second cooling process.
%K 双辊薄带连铸
%K 低碳微合金钢
%K 凝固组织
%K 原奥氏体晶粒
%K 析出&lt
%K /br&gt
%K Key words： twin-roll strip casting low-carbon microalloyed steel solidification structure prior austenite grain precipitate
%U http://xuebao.neu.edu.cn/natural/CN/abstract/abstract10529.shtml