Fracture failure analysis of 30CrNi2MoVA shell grabber hook
Aiming at the early fracture in the service process of the shell grabber hook,the macroscopic fracture analysis,crack analysis,microstructure analysis,fracture SEM analysis and so on were carried out to study the fracture reason.The results show that the failure mode of the shell grabber hook is high stress and low cycle fatigue fracture,the crack originates from the processing corner where the shape of the shell grabber hook is sudden,and small fatigue cracks have been generated at the processing tool mark at the corner of the shell grabber hook without fracture.The macro fracture crack expansion area has obvious fatigue arc characteristics,and the SEM shows typical fatigue strip characteristics.The crack source area has normal organization,and no micro-defects such as inclusions and holes are found.The Mises stress value of the tooth root calculated by finite element simulation is 1 207 MPa,and the stress concentration of the tooth root structure and the stress concentration caused by the machining tool mark defect are superimposed together,resulting in fatigue fracture failure.The Mises stress value calculated by the simulation is significantly reduced by changing the arc transition design at the root of the tooth.
shell grabber hookfatigue fracturefracture morphologystress concentrationfinite element analysis
万方数据
维普
