1. internal stress is generated during lining plate casting, resulting in cracks in lining plate;
2. the fracture of the lining plate is loose, with pores and slag inclusion, which leads to the reduction of the strength of the lining plate, and the hydrogen pores and oxygen pores greatly reduce the high temperature resistance of the material, making the lining plate easier to melt;
3. defective repair welding on the surface of individual lining plates is one of the reasons for the cracking of lining plates;
4. the casting fillet near the bolt hole is small, the wall thickness of the remaining lining plate at the bolt hole is too small, and the position is too high (close to the edge of the lining plate, about 30mm), resulting in weak links in the lining plate, which is also one of the reasons for the cracking of the lining plate;
5. the casting dimension of the lining plate is out of tolerance, resulting in too small gap between the lining plate and the lining plate after the lining plate is installed, resulting in extrusion after thermal expansion of the lining plate, resulting in cracking of the lining plate.