The failure condition of stainless steel rivets: macroscopic and microscopic observation results show that the rupture characteristics of rivets are basically the same, the area of fatigue area is large, and the area of the instantaneous breaking area is small, which can distinguish the fractures of stainless steel rivets and mechanical external forces. The fracture mode of the failed rivet is comprehensively judged as fatigue fracture.
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 stainless steel rivet hot nail head is weaker than that of the cold head, but the fracture failure appears in the cold pier. Therefore, the failure of the rivet riveting should be independent of the material. The rivet fractures contain a large and a small fatigue fracture zone.
Under normal circumstances, stainless steel rivets are generally subjected to shear stress and fatigue fracture should not occur. From the point of occurrence of the fracture at the position of the cold head, and the presence of circumferential friction marks and the occurrence of wear marks at the rupture position of the rivet rod, the rivet nail head should be detached due to fretting wear.