Q345B钢保护渣显微结构及矿相组成研究  

Research of Q345B steel protective slag microstructure and the mineral composition

作　　者：宋土顺 朱立光 王杏娟 肖鹏程 王键涛 

机构地区：[1]华北理工大学冶金与能源学院,河北唐山063009 [2]华北理工大学矿业工程学院,河北唐山063009 [3]河北省地矿局第二地质大队,河北唐山063004

出　　处：《连铸》2017年第5期29-32,共4页Continuous Casting

基　　金：河北省高层次人才博士后资助项目(B2016003016);河北省自然科学基金(E2017209217)

摘　　要：保护渣科学应用是高效化连铸的关键技术,连铸保护渣的重要功能是液渣的润滑和结晶层的传热作用,这些关键作用主要取决于显微结构和矿相组成。然而,Q345B钢连铸保护渣的显微结构及矿相组成国内外相关报道较少,本次研究以实际生产过程中连铸结晶器内坯壳上残留的保护渣渣膜为研究对象,通过岩石学和分析软件相结合的方法开展了研究,取得以下认识:(1)渣膜结构从铸坯表面至结晶器内壁包括结晶层、玻璃层、结晶层和玻璃层4层结构,渣膜厚度分布在0.15~5.00 mm之间,结晶层厚度分布在0.1~1.5 mm之间。(2)渣膜结晶矿相由黄长石、枪晶石和硅灰石组成,同时具有分带性和流动构造,靠近结晶器内壁析出的枪晶石和硅灰石具有晶体成核速率高和成长慢的特点,而分离析晶形成的黄长石晶体发育较粗,黄长石晶体体积的变大可能导致晶内裂缝增多,是导热率下降的主要原因。本次研究有助于改善保护渣成分,提高保护渣的润滑和传热性能,控制铸坯质量,具有一定的理论意义和实际运用价值。Protecting slag science and technology is the key to efficient continuous casting, continuous casting is the most important function of protecting slag liquid slag lubrication and crystallization layer heat transfer effect, the key role mainly depends on the microstructure and phase composition. Q345B steel continuous casting, however, the microstructure of slag composition reported less, both at home and abroad and the research to the actual production process of continuous casting crystallizer shell on the protection of the residual Tony membrane as the research object, by using the method of combining petrology and analysis software has carried out research, obtained the following understanding： （1） the structure of the flux film from the slab surface to the inner wall of the crystallizer including Crystallization, glass layer 4 layer structure, crystallization and glass layer, thickness of slag film distribution between 0.15-5.00 mm, crystal layer thickness distribution is between 0.1-1.5 mm. （2） the slag film consists of melilite, cuspidine and crystalline mineral phase of wollastonite has zonality and the flow structure at the same time, the precipitation near the inner wall of the crystallizer cuspidine and wollastonite has the characteristics of the high speed of crystal nucleation and growth is slow, the formation of separation and crystallization melilite crystal growth is thick, yellow feldspar crystal volume increase in the number of larger may cause intracrystalline cracks, is the main reason for decline in thermal conductivity.This study helps to improve protection of slag composition, improve lubrication and heat transfer performance of protecting slag, casting quality control, has certain theoretical significance and practical application value.

关 键 词：连铸 保护渣 显微结构 Q345B钢 

分 类 号：TF777[冶金工程—钢铁冶金]