This study has focused on the morphology and distribution of inclusions and precipitates modified by rare earth(RE)elements,which has a decisive influence on microstructure,corrosion properties and impact behaviors in...This study has focused on the morphology and distribution of inclusions and precipitates modified by rare earth(RE)elements,which has a decisive influence on microstructure,corrosion properties and impact behaviors in Q355 low alloy steel.Characterized by the method of electrolytic extraction and ASPEX-scanning electron microscopy(ASPEX-SEM),small-sized spherical RE inclusions have been modified to replace elongated MnS and large-sized Al_(2)O_(3).Q355RE steel after RE alloying has lower corrosion rate and higher value ofα/γ,due to the formation of stable and dense rust layers.Q355RE steel also exhibits better resistance to fracture at low temperature,owing to the presence of RE modification to inclusions and its effects on reducing crack initiation and propagation.Nano-scale RE precipitates containing sulfur and phosphorus is observed along grain boundaries by transmission electron microscopy(TEM).The purification of grain boundaries by RE is beneficial to the improvement of corrosion and impact properties.展开更多
基金financially supported by the Open Project of State Key Laboratory of Advanced Special Steel,the Shanghai Key Laboratory of Advanced Ferrometallurgy,the Shanghai University and the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200)the National Natural Science Foundation of China(No.52031004).
文摘This study has focused on the morphology and distribution of inclusions and precipitates modified by rare earth(RE)elements,which has a decisive influence on microstructure,corrosion properties and impact behaviors in Q355 low alloy steel.Characterized by the method of electrolytic extraction and ASPEX-scanning electron microscopy(ASPEX-SEM),small-sized spherical RE inclusions have been modified to replace elongated MnS and large-sized Al_(2)O_(3).Q355RE steel after RE alloying has lower corrosion rate and higher value ofα/γ,due to the formation of stable and dense rust layers.Q355RE steel also exhibits better resistance to fracture at low temperature,owing to the presence of RE modification to inclusions and its effects on reducing crack initiation and propagation.Nano-scale RE precipitates containing sulfur and phosphorus is observed along grain boundaries by transmission electron microscopy(TEM).The purification of grain boundaries by RE is beneficial to the improvement of corrosion and impact properties.
