With the transformation and upgrading of rolling equipment in China, the rolling mill is developing towards automation, continuity and heavy-duty, and the demand for large rolls is increasing day by day. With the development of the market, the output of large-scale normal roller with the blank weight of more than 70 t is increasing gradually. The casting defects such as shrinkage cavity, shrinkage porosity, segregation, inclusion and crack are easy to occur in the casting of large roll casting. In order to ensure the quality of the products, some improvements have been made in the aspects of pouring mode, electric heating technology, selection of molding materials, etc. by using theanalysis software “Huazhu CAE”, the computer simulation of the filling and solidification process of the castings has been carried out, and the process parameters such as pouring temperature, riser diameter and so on have been optimized, and good results have been achieved.
65crnimo is used as the material of large normal roll casting.
It is easy to produce shrinkage, porosity, segregation, inclusion and crack in large roll casting. Therefore, the casting process must be selected reasonably in the process design.
(1) Reasonable improvement of the ratio of coating and molding sand can effectively avoid surface quality problems such as sand sticking and cracks.
(2) The quality problems such as segregation, inclusion, crack and slag inclusion are effectively solved by using the bottom injection technology of double package and double nozzle, numerical simulation of roll filling and solidification process and electric heating.