The formation of cracks in stainless steel sheets can be caused by a variety of factors. Here are some common reasons:
1. Stress Corrosion Cracking (SCC)
Corrosive media: When stainless steel is exposed to a specific corrosive environment (such as a chloride ion environment), stress corrosion cracking may occur.
Stress action: Materials are more likely to crack when they are under stress, especially in high temperature or high concentration of corrosive media.
2. Welding cracks
Heat-affected zone (HAZ): During the welding process, the weld area and the heat-affected zone around it may crack due to rapid cooling or thermal stress concentration.
Welding defects: Improper welding techniques, mismatched welding materials, or contaminants that are not removed during the welding process may also cause cracks.
3. Cold working cracks
Processing stress: During the cold working process, if the material is subjected to excessive deformation, cracks may occur.
Material properties: Some stainless steel alloys have poor crack resistance to cold working and are prone to cracking during processing.
4. Heat treatment cracks
Rapid cooling: During the heat treatment process, rapid cooling (such as quenching) may cause residual stress inside the stainless steel, thus forming cracks.
Excessive heat treatment: Excessive heat treatment temperature or inappropriate holding time may also cause cracks.
5. Material defects
Internal defects: During the production process, if the stainless steel plate has internal pores, inclusions or other defects, it may cause cracks in subsequent use.
Uneven composition: Uneven alloy composition can also lead to local fragility, thus forming cracks.
6. Environmental factors
Temperature changes: The cycle of stainless steel in high and low temperature environments may cause thermal expansion and contraction, thus forming cracks.
Chemical corrosion: Certain chemicals (such as acids, alkalis, etc.) are highly corrosive to stainless steel, which increases the risk of cracks.
7. Mechanical fatigue
Repeated load: When subjected to repeated loads for a long time, the material will fatigue, resulting in the generation of small cracks and gradually expanding.
In short, the formation of cracks in stainless steel sheet is a complex process involving multiple factors such as the chemical composition of the material, processing technology, and use environment. In order to reduce the occurrence of cracks, appropriate measures are usually required in material selection, processing and welding processes to ensure the durability and reliability of stainless steel sheet.
