双辊连铸高磷钢薄带中的铁素体_邱以清.pdfVIP

双辊连铸高磷钢薄带中的铁素体 ·1 · 双辊连铸高磷钢薄带中的铁素体 邱以清 刘振宇 李 娜 王国栋 （东北大学轧制技术及连轧自动化国家实验室，沈阳 110819 ） 摘 要 通过金相组织观察等手段，分析了不同磷含量双辊连铸薄带中的铁素体。实验结果表明，与同样磷含量的 铸锭相比，铸带中的铁素体体积比明显大；对于同一个铸带，表层内铁素体体积比小于中心区域，且磷含量越低， 表层内铁素体体积比越小；随着磷含量的升高，铸带中的铁素体逐渐由针状向表面圆滑的块状转变。通过理论分析 得出，快速冷却有利于钢中铁素体的稳定；表面圆滑的块状铁素体是由钢液中直接析出的而针状铁素体是由固态奥 氏体中析出的。 关键词 双辊薄带连铸 磷含量 铁素体 快速冷却 Ferrite in Twin-Roll Cast Strip Containing High P Qiu Yiqing Liu Zhenyu Li Na Wang Guodong (The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang, 110819) Abstract The ferrite in twin-roll cast strips of different P content were analyzed by the observation of metallographic structure. The results showed that the volume fraction of ferrite in cast strip was obviously large compared with that in cast billet of the same P content; for a cast strip, the volume fraction of ferrite in surface layer was smaller than in center area and reduced by the lower P content; and the ferrite in cast strip was gradually transformed from acicular form into polygonal form of smooth surface with increasing of the P content. It was obtained that rapid cooling favors the stabilizing of ferrite in steel, and the polygonal ferrite of smooth surface is directly precipitated from liquid steel while the acicular ferrite from solid austenite. Key words twin-roll strip casting, P content, ferrite, rapid cooling 双辊薄带连铸是把钢液直接浇注成薄带的近终形技术。凝固与变形同时进行的特点决定了它具有流程 短、投资少、生产成本低等优势，并可加工Si 钢、TWIP 钢等难变形合金[1~5] 。此外，由于钢液冷却速度高 3 [6,7] 达10~10 ℃/s ，双辊连铸薄带中有可能出现与快速凝固类似的组织。因而近年来双辊薄带连铸一直是国内 外关注的热点。 Zhou G P 等的研究表明，双辊连铸高磷钢薄带表层富磷而基体贫磷，并把其同时具有优异的耐候性与 [8-9]，但并没有进一步探讨双辊连铸高磷钢薄带的室温组织。事实 良好的力学性能归功于磷的这种异常分布 上，磷的存在及快速冷却必然会造成钢的组织