■ The casting process design of girth gear must ensure the compactness of the teeth and casting defects are not allowed in the teeth, therefore, there are strict requirement about the design of the riser and pouring temperature.
■ It is necessary to ensure that there are no defects such as shrinkage pores, shrinkage pine, inclusions and coarse grains in the installation part of the mill barrel, so there are strict requirement about riser position and pouring temperature.
■ Cold iron is used in the parts of assembling holes to improve the compactness of castings.
■ Girth gears are divided into integral, 1/2 and 1/3 structures according to their structure. When casting, they must be poured as a whole so as to ensure the consistency of chemical composition of each part and the consistency of various conditions, so that the performance is consistent and the effect is consistent.