1.Jiujiang Pinggang Iron and Steel of Fangda Group Co., Ltd., Jiujiang 332500, Jiangxi, China 2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China 3. Chengdu Branch Institute, China National Heavy Machinery Research Institute Co., Ltd., Chengdu 610021, Sichuan, China
Abstract��The temperature field and cooling rate especially for surface center and corner, which located at 0-5mm under the slab surface were calculated along the casting direction based on the two- dimensional heat transfer and solidification model of slab continuous casting, combined with the actual casting process conditions. The results show that the temperature of slab drops rapidly from liquidus temperature to 1200-900�� in the mold, and then drops slowly in the secondary cooling zone with the corner 200�� about lower than the surface center. As to the cooling rate, for 0-5mm layer under surface, it is up to 40��/s in the mold with the average cooling rate about 10��/s. For the secondary cooling zone, it is about 3-6��/s in the foot zone, and then drops to a steady value about 0. 1-0. 5��/s. The results can be used to optimize the continuous casting process and provide the basis for the control of the surface and corner transverse cracking of continuous casting slabs based on the solidification and phase transformation principles.
�ų�ΰ �������ף���������������ż�Ȫ. �������������¶ȳ������ٷֲ����Ͻ�ֱ�������Ƶ�Ӱ��[J]. �����о�ѧ��, 2018, 30(7): 523-528.
DU Chen- wei,,WANG Chun- lei,LI Bo,LI Bin,MA Bing- chuan,ZHANG Jia- quan. Effect of temperature field and cooling rate along casting direction on surface transverse cracks of microalloyed steel. , 2018, 30(7): 523-528.
Dippenaar R, Moon S C, Szekeres E S. Strand surface cracks: The role of abnormally large prior-austenite grains[J]. Iron & Steel Technology, 2007, 4(7): 105-115.
[3]
Mintz B, Yue S, Jonas J J. Hot ductility of steels and its relationship to the problem of transverse cracking during continuous casting[J]. International Materials Reviews, 1991, 36(1): 187-220.
[4]
Maehara Y, Yasumoto K, Tomono H, et al. Surface cracking mechanism of continuously cast low carbon low alloy steel slabs[J]. Materials Science and Technology, 1990, 6(9): 793-806.
Bernhard C, Reiter J, Presslinger H. A model for predicting the austenite grain size at the surface of continuously-cast slabs[J]. Metallurgical and Materials Transactions B, 2008, 39(6): 885-895.
Du C, Zhang J, Wen J, et al. Hot ductility trough elimination through single cycle of intense cooling and reheating for microalloyed steel casting[J]. Ironmaking & Steelmaking, 2016, 43(5): 331-339.
[12]
Zhong J, Li Y G, Wang Q, et al. Reducing surface cracking in hot charged HSLA cast slabs by surface quenching prior to hot charging-experimental study on heat transfer behaviour[J]. Ironmaking and Steelmaking, 2015, 42(4): 302-310.
2018, Vol. 30 
