1. Improper material selection is the main cause of failure in the material. It is common that designers make decisions based on the conventional performance indicators of the materials, and the defects of the material itself are also the reason.
2. When installing and using the part that has been invalidated, it may cause failure to cooperate with over looseness, too tight, fixing, and improper operation.
3. Due to poor processing process control, it will cause various defects and cause failure. Such as improper control of heat treatment process, resulting in overheating, insufficient ignition, decarbon, etc. Phenomenon such as overheating or over -burning. Poor cold processing technology can cause too low smoothness. Excessive knife marks, grinding cracks, etc. can cause parts to fail.
4. The reason for the design is that the structure and shape of the design cause parts to fail, such as the high stress concentration source of the high stress zone of the part. Second, the working conditions of the parts make a mistake.
