Analysis of Fatigue Fracture with Scanning Electron Microscopy of Valve Spring Steel

Valve spring steel for engines, belonging to the class of super clean steel, must be supported due to their application, high numbers of cycles in fatigue and cannot suffer any type of failure, which would be catastrophic for the vehicle. From these considerations, it was tested in axial fatigue, a test that can detect possible internal defects in their structure, caused by inclusions, a class of valve spring steel, where it aimed to discover the values of their fatigue life, followed by an analysis of microstructural fracture surface by SEM (scanning electron microscopy). It was proved, after testing, the specimens tested broke up a number of cycles always compatible with the life work of a valve spring and that fractures always occurred by surface defects in the specimens.