Low cycle fatigue property of hot rolled wear-resistant steel NM300
In order to explore the service status of advanced wear-resistant parts of commercial vehicles and to understand the ability of key wear-resistant parts to resist fatigue failure due to turbulence,weather,road conditions and other reasons during driving,low-cycle fatigue tests were carried out with a hot-rolled TRIP wear-resistant steel plate NM300 with a thickness of 3.5 mm.The fatigue performance of NM300 under different strain amplitudes was studied,the characteristic curve of cyclic stress response and the stress-strain hysteresis loop were obtained,the Masing effect of NM300,the relationship between cyclic stress and inelastic strain,and the relationship between cyclic strain and fatigue life were studied,and the low-cycle fatigue fracture mechanism of NM300 under different strain amplitudes was analyzed.The experimental results show that NM300 exhibits cyclic hardening under the control of low strain amplitude,and cyclic softening under the control of high strain amplitude,and the cyclic response stress of NM300 increases gradually with the increase of strain amplitude.When the strain amplitude is less than 0.37％,the cycle life can reach more than 104 times.When the strain amplitude is less than 0.19％,the cycle life can reach more than 105 times.The fatigue fracture of NM300 has typical fatigue fracture characteristics,which can be divided into three zones:fatigue source zone,crack propagation zone and transient fracture zone.With the increase of strain amplitude,the crack propagation zone area decreases and the surface becomes rough.The fracture forms of fatigue fracture are mainly intergranular brittle fracture and intergranular ductile fracture.According to the service conditions of hot-rolled wear-resistant steels,the fatigue performance is considered to be excellent.
NETL
NSTL
万方数据
维普
