On the Secondary Cooling of Continuous Casting

Study on continuous casting of steel-II

Abstract

A series of experiments on the secondary cooling of continuous casting of steel was carried out. As the authors defined in the first report, it was stated that the solidification in the spray zone was“ the secondary solidification” and the cooling of this stage was “the secondary cooling”.
Based on the principle of normal ingot casting, authors thought that main factors affecting the secondary solidification of continuous casting should be as follows:
Evenness of cooling in the spray zone
Intensity of the spray cooling
Casting temperature
Casting speed
Experiments on the relationship between these factors and their effects on continuous cast billet mainly of square type revealed the following facts:
(1) To prevent deformation and cracks of billets, it was necessary to set up roller aprons and to keep evenness of the spray cooling. (Photo. 1)
(2) Intensity of the spray cooling affected on inner cracks of billets. There was the limit intensity of spray cooling for each grade of steel to get rid of inner cracks of billets (Table 2, 3 and Photo. 2).
(3) Too high casting temperature induced inner cracks of billets (Table 5 and Photo. 3).
These relationships in continuous casting were just the same as those in normal ingot casting. Although not confirmed experimentally, the limit intensity of the spray cooling should be varied with casting speed.