Research of Q345B steel protective slag microstructure and the mineral composition
SONG Tu-shun1,2， ZHU Li-guan1， WANG Xing-juan1， XIAO Peng-cheng1， WANG Jian-tao3
（1. College of Metallurgy and Energy，North China University of Science and Technology， Tangshan 063009， Hebei，China 2. Mining engineering institute，North China University of Science and Technology， Tangshan 063009， Hebei， China 3. The Second Geological Brigade of Hebei Geology and Mineral Exploration Bureau， Tangshan 063004， Hebei，China）
Abstract：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： ①the 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.
宋土顺， 朱立光， 王杏娟， 肖鹏程， 王键涛. Q345B钢保护渣显微结构及矿相组成研究[J]. , 2017, 36(5): 29-32.
SONG Tu-shun，， ZHU Li-guan， WANG Xing-juan， XIAO Peng-cheng， WANG Jian-tao. Research of Q345B steel protective slag microstructure and the mineral composition. , 2017, 36(5): 29-32.
Meng Y, Thomas B G.Simulation of Microstructure and Behavior of Interfacial Mold Slag Layers in Continuous Casting of Steel[J].Isij International, 2006, 46(5):660-669
[3]
Dilellio J A, Young G W.An asymptotic model of the mold region in a continuous steel caster[J].Metallurgical & Materials Transactions B, 1995, 26(1):1225-1241
[4]
Chavez.Heat transfer in mold flux-layers during slab continuous casting[J].Steelmaking Conference Proceedings, 1996, :321-329
Yamauchi A, Sorimachi K, Sakuraya T, et al.Heat Transfer between Mold and Strand through Mold Flux Film in Continuous Casting of Steel[J].Isij International, 1993, 33(1):140-147
2017, Vol. 36 
