1. Causes:
(1) Impact or damage to the exposed surface of the high-temperature box fan can result in collision marks, damage, or wear marks.
(2) Prolonged vibration of the high-temperature box fan can cause cracks to form in the stepped section of the shaft and on its surface.
(3) Improper maintenance of the exposed surface leads to rust.
2. Solutions:
(1) Use a flat file to smooth the surface, then wipe it with oil-soaked emery cloth.
(2) If the damage is severe, exceeds 1–2 mm in depth, or covers an area greater than 10 mm², the shaft must be replace
