In the process of continuous casting, the cooling rate is the key factor affecting and deciding the slab surface microstructure. In this study, confocal laser scanning microscopy was used for in situ observation of, and research on, slab surface microstructure evolution under different cooling rates. It was found that the slab microstructure was uniform, and there was no obvious filmlike proeutectoid ferrite or chainlike microalloyed element precipitation in the prior austenite grain boundary under the cooling rate of 3-6uC s 21 . The results of hot tensile experiments showed that this microstructure had a higher hot ductility, which contributed to the virtual disappearance of the brittle trough and reduction of the steel's cracking susceptibility.

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At the beginning of the 21st century, China began to transform and upgrade the old urban industrial areas. At present, it is relatively lack to research the post-evaluation system of functional upgrading and transformation for old urban industrial areas. This paper chooses and analyzes 24 typical projects of regeneration and transformation for old urban industrial areas through literature research. On the basis of analyzing the relevant literature research, policy implementation and practice results of typical projects, this paper proposes a post-evaluation system with comprehensive influence as the target and 5 influence dimensions and 21 evaluation factors through combining qualitative and quantitative techniques. Based on this, the connotation of evaluation factors is analyzed, so as to form a practical post-evaluation system of comprehensive influence.