In order to study the transformation mechanism and influencing factors of inclusions during the solidifica-tion and cooling process of aluminum deoxidized calcium treated steel,the transformation phenomenon of inclusions in steel with different cleanliness levels was analyzed by taking molten steel samples in tundish and continuous cast-ing slab samples of S335 structural steel.It was found that during the production process of Al-killed Ca treated S335 structural steels,inclusions underwent a transformation from homogeneous CaO-Al2O3 to multiphase Al2O3+CaS from the molten steel in tundish to the continuous casting slab,accompanied by an increase in the number densi-ty and size of inclusions.The transformation mechanism of inclusions during the solidification and cooling process of steel was revealed through thermodynamic calculations.It was found that with the decrease of w(T.[Ca])/w(T.[O])and the increase of w(T.[O])/w(T.[S])in the steel,the weight percent of CaO in inclusions in the molten steel decreased.At the same time,the precipitation temperature and precipitation amount of CaS in inclu-sions decreased during the solidification and cooling process.Based on the transformation phenomenon of inclusions during the solidification and cooling of steels,it could be concluded that when analyzing the composition of inclusions in molten steel,rapid cooling must be carried out after taking out the molten steel sample to avoid the transformation of inclusions during the solidification and cooling process and improve the accuracy of detection.
关键词
S335结构钢/连铸/凝固冷却/夹杂物转变/洁净度/热力学
Key words
S335 structural steel/continuous casting/solidification and cooling/inclusion transformation/cleanli-ness/thermodynamic
维普
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