As we all know, the girth gear is the key part of the cement plant raw mill. The large ring gear needs to drive the entire cylinder to run for a long time. Therefore, the girth gear has higher requirements on mechanical properties, dimensional tolerances, surface quality, and internal quality.
As a professional girth gear casting manufacturer, HENAN KINGMAN M&E COMPLETE PLANT CO., LTD has rich casting experience and strictly controls the quality during the entire casting process of the large girth gear to ensure high quality.
Due to the particularity of the shape of the large girth gear, the small R area of the non-machined surface has a thin wall. If the pouring process is not appropriate, casting defects such as loose metal structure, slag inclusion, pores, coarse grains, and surface cracks are generally prone to occur in the pouring process. As a result, ultrasonic and magnetic particle inspections do not meet the requirements of relevant national regulations.
Therefore, in the casting process, the composite requirements of the pouring process are strictly required, and the molten steel produced by the refining ladle is used as much as possible and poured with full risers. At present, some large state-owned enterprises in China adopt non-full riser pouring due to consideration of cost; generally, the number of risers of large girth gear is equal to the number of reinforcing rib plates, and 8 to 12 risers are adopted. In this way, the cost of the blank is controlled, but the quality of the blank is reduced, and the quality problem of the casting blank is basically solved by the method of welding repair. However, such a blank quality is difficult to pass magnetic particle inspection after finishing.
In addition, before pouring, computer simulation software is used to simulate the pouring plan, so as to modify the pouring model in time, and to better control the quality of the blank.
The above are the problems and countermeasures in the casting process of the girth gear introduced by KINGMAN for you. If you still have questions, you can consult us online, or visit our website for more information.