The uniaxial time-dependent strain cyclic behaviors and ratcheting of SS304 stainless steel were studied at high temperatures （350 ℃ and 700 ℃）. The effects of straining and stressing rates, holding time at the pe...The uniaxial time-dependent strain cyclic behaviors and ratcheting of SS304 stainless steel were studied at high temperatures （350 ℃ and 700 ℃）. The effects of straining and stressing rates, holding time at the peak and/or valley of each cycle in addition to ambient temperature on the cyclic softening/hardening behavior and ratcheting of the material were discussed. It can be seen from experimental results that the material presents remarkable time dependence at 700 ℃, and the ratcheting strain depends greatly on the stressing rate, holding time and ambient temperature. Some significant conclusions are obtained, which are useful to build a constitutive model describiog the time-dependent cyclic deformation of the material.展开更多
Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive mod...Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive model and continuum damage mechanics theory, the damage-coupled multi-axial time-dependent constitutive model and fatigue failure model were proposed. In the model, the evolution equation of damage was introduced in and the time-dependent effects, e.g. holding time, loading rate, were taken into account. The model was applied to the simulation of whole-life cyclic deformation behaviors and prediction of LCF life for SS304 stainless steel in multiaxial time-dependent low cycle fatigue tests. It is shown that the simulated results agree well with experimental ones.展开更多
The effects of the substrate temperature on the deposition and microstructure of the 304 stainless steel （SS） cold gas dynamic spraying （CGDS） coatings were investigated. It was found that the higher substrate tem...The effects of the substrate temperature on the deposition and microstructure of the 304 stainless steel （SS） cold gas dynamic spraying （CGDS） coatings were investigated. It was found that the higher substrate temperature could increase the deposition rate of the 304 SS particles,even the oxide films existed at the interface. There was a critical oxide film with a thickness of 3 -4 um which could be destroyed by the impacted particles. The micro-hardness and microstructure of the 304 SS coatings under different substrate preheating temperatures were almost the same.展开更多
基金Item Sponsored by National Natural Science Foundation of China (NSFC10402037) Theoretical Research Fund of SouthwestJiaotong University (2005XJB23)
文摘The uniaxial time-dependent strain cyclic behaviors and ratcheting of SS304 stainless steel were studied at high temperatures （350 ℃ and 700 ℃）. The effects of straining and stressing rates, holding time at the peak and/or valley of each cycle in addition to ambient temperature on the cyclic softening/hardening behavior and ratcheting of the material were discussed. It can be seen from experimental results that the material presents remarkable time dependence at 700 ℃, and the ratcheting strain depends greatly on the stressing rate, holding time and ambient temperature. Some significant conclusions are obtained, which are useful to build a constitutive model describiog the time-dependent cyclic deformation of the material.
基金supported by the Fundamental Research Funds for the Central Universities (No.SWJTU09ZT35)National Science Fund for Distinguished Young Scholars of China (No.11025210)
文摘Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive model and continuum damage mechanics theory, the damage-coupled multi-axial time-dependent constitutive model and fatigue failure model were proposed. In the model, the evolution equation of damage was introduced in and the time-dependent effects, e.g. holding time, loading rate, were taken into account. The model was applied to the simulation of whole-life cyclic deformation behaviors and prediction of LCF life for SS304 stainless steel in multiaxial time-dependent low cycle fatigue tests. It is shown that the simulated results agree well with experimental ones.
文摘The effects of the substrate temperature on the deposition and microstructure of the 304 stainless steel （SS） cold gas dynamic spraying （CGDS） coatings were investigated. It was found that the higher substrate temperature could increase the deposition rate of the 304 SS particles,even the oxide films existed at the interface. There was a critical oxide film with a thickness of 3 -4 um which could be destroyed by the impacted particles. The micro-hardness and microstructure of the 304 SS coatings under different substrate preheating temperatures were almost the same.
