Study on Fatigue Crack Propagation Rate and Corrosion Mechanism of 60Si2Mn Spring Steel under Salt Spray Environment

With the aim of studying the fatigue crack propagation rate law and corrosion mechanism of 60Si2Mn， a commonly used material for high-speed track ballastless railway fastener clips in coastal environment，a neutral salt spray chamber was used to simulate the marine environment. The fatigue evaluation of 60Si2Mn spring steel compact tensile (CT) samples under different salt spray corrosion time conditions was carried out and the corrosion mechanism was analyzed through salt spray corrosion and fatigue crack propagation experiments. The surface morphology of the corroded samples was observed with a scanning electron microscope (SEM)，and the corrosion products of the samples were analyzed with an X-ray diffractometer (XRD). Then the fatigue crack propagation rate test was carried out， the crack propagation length was measured based on the flexibility method， and the test data was processed by the seven-point incremental polynomial method. Results showed that with the increase of corrosion time， the corrosion rate