Low technology level and poor quality
① Casting machining allowance is large. Due to the lack of scientific design guidance, it is difficult for process designers to control the deformation problem based on experience, and the machining allowance of casting is generally 1-3 times larger than that of foreign countries. Large machining allowances, severe energy consumption of castings and raw materials, long processing cycles, and low production efficiency have become bottlenecks restricting the development of the industry.
② Large-scale castings have serious segregation and inclusion defects. After the solidification of large-scale steel castings and large-sized steel ingots, macrosegregation and coarse grains exist in the root of the feeder and the thick section of the casting.
③ The problem of casting cracks is serious.
④ The design of the pouring system is unreasonable. Due to improper design, there are defects such as gas entrainment and inclusion, resulting in low casting yield and qualified rate.