As a Carbon Steel Solid Rivet Manufacturer, we will discuss Failure mode of rivets and causes of failure with you.
Failure mode: Through the fracture macro and microscopic observation results, the fracture characteristics of the colored rivets are basically the same, the area of the fatigue zone is large, the area of the instantaneous break zone is small, and the color rivet and the mechanical external force are broken. The fracture mode of the failed rivet is comprehensively judged as fatigue fracture.
The colored rivet fractures contain two large and one fatigue fracture zones. Under normal conditions, colored rivets are generally subjected to shear stress and fatigue fracture should not occur. From the break, the cold nail head position appears, and there is a circumferential friction trace. The rivet rods also have wear marks at the break position, and the rivet heads should be detached due to fretting wear.
Failure reason: the failure rivet fracture observation shows that there is no metallurgical defect such as inclusions in the fracture origin area, and the metallographic structure has no abnormality. The material strength of the colored rivet hot nail head is weaker than that of the cold head, but the fracture failure appears in the cold pier. end. Therefore, the failure of the rivet riveting of the colored rivet should be independent of the material.