The magnetic properties of as quenched and annealed Fe 73.5 Ag 1Nb 3Si 13.5 B 9 alloys were investigated. X ray diffraction was used to monitor the structure changes of the samples under different anneali...The magnetic properties of as quenched and annealed Fe 73.5 Ag 1Nb 3Si 13.5 B 9 alloys were investigated. X ray diffraction was used to monitor the structure changes of the samples under different annealing temperatures. It was found that by Cu addition, the crystallization temperature T x1 of Fe Nb Si B alloy is decreased, whereas by Ag addition, the T x1 is increased. A small amount of α Fe and Ag were obtained after the sample was annealed at 500℃ for 1 h. With increasing the annealing temperature, Fe 23 B 6、 Fe 2B、 Fe 3B were separated out and magnetic properties of the samples were impaired quickly. A mostly single nanocrystalline grain of α Fe phase could not be obtained in the annealed samples.展开更多
Effects of alloy elements Cr, W, Ce, and Si on oxidation behavior at 750℃ in air and stress-rupture properties of P92 steel have been investigated. The proper increase in elements Cr, W, and Ce improved to varying de...Effects of alloy elements Cr, W, Ce, and Si on oxidation behavior at 750℃ in air and stress-rupture properties of P92 steel have been investigated. The proper increase in elements Cr, W, and Ce improved to varying degrees both oxidation resistance by either facilitating more protective Cr2O3 or modifying surface morphologies and stress-rupture life largely attributed to the formation of fine Laves phase. The excessive addition of Si significantly improved oxidation resistance of P92 steel, but dramatically impaired the stress-rupture life due to the formation and coarsening of Laves phase. The results indicate that proper additions of Cr, W, and Ce are beneficial for the comprehensive property of P92 steel.展开更多
A new series of economical Mo-free duplex stainless steels 21.5Cr-3.5Ni-xW-0. 2N （x = 1.8 -- 3. 0, mass%） have been developed. The effects of W on mechanical properties and corrosion resistance were investigated, an...A new series of economical Mo-free duplex stainless steels 21.5Cr-3.5Ni-xW-0. 2N （x = 1.8 -- 3. 0, mass%） have been developed. The effects of W on mechanical properties and corrosion resistance were investigated, and the microstructures were analyzed by optical microscopy, X-ray diffraction, transmission electron microscopy and electron backscatter diffraction. The designed steels have a balanced ferrite-austenite relation and are free of sigma phase after solution treatment at 750--1 300 ~C for 30 min followed by water-quenching, whereas a small number of Cr23 C~ precipitates were found after solution treatment at 750 ~C. After solution treatment at 1050 ℃, the steel with 1.8~ （mass percent） W exhibits the highest room temperature tensile strength due to the strongest work hardening effect, while the steel with 3.0% （mass percent） W exhibits the highest fracture elongation owing to the transformation-in- duced plasticity （TRIP） effect. The ductile-brittle transition （DBT） and martensite transformation are respectively found in the ferrite and austenite, which deteriorates the impact properties of the steels with the increase of W con- tent. The corrosion resistance of the designed steels is improved with the increase of W content. The pitting resistance of austenite is obviously better than that of ferrite for the designed alloys. Among the designed steels, the steel with 1.8% （mass percent） W is found to be an optimum steel with excellent comprehensive properties and lowest production cost.展开更多
文摘The magnetic properties of as quenched and annealed Fe 73.5 Ag 1Nb 3Si 13.5 B 9 alloys were investigated. X ray diffraction was used to monitor the structure changes of the samples under different annealing temperatures. It was found that by Cu addition, the crystallization temperature T x1 of Fe Nb Si B alloy is decreased, whereas by Ag addition, the T x1 is increased. A small amount of α Fe and Ag were obtained after the sample was annealed at 500℃ for 1 h. With increasing the annealing temperature, Fe 23 B 6、 Fe 2B、 Fe 3B were separated out and magnetic properties of the samples were impaired quickly. A mostly single nanocrystalline grain of α Fe phase could not be obtained in the annealed samples.
文摘Effects of alloy elements Cr, W, Ce, and Si on oxidation behavior at 750℃ in air and stress-rupture properties of P92 steel have been investigated. The proper increase in elements Cr, W, and Ce improved to varying degrees both oxidation resistance by either facilitating more protective Cr2O3 or modifying surface morphologies and stress-rupture life largely attributed to the formation of fine Laves phase. The excessive addition of Si significantly improved oxidation resistance of P92 steel, but dramatically impaired the stress-rupture life due to the formation and coarsening of Laves phase. The results indicate that proper additions of Cr, W, and Ce are beneficial for the comprehensive property of P92 steel.
基金Item Sponsored by National Key Technology Research and Development Program in 12th Five-Year Plan of China(2012BAE04B02)Innovation Fund of Education Commission of Shanghai Municipality of China(12CXY10)
文摘A new series of economical Mo-free duplex stainless steels 21.5Cr-3.5Ni-xW-0. 2N （x = 1.8 -- 3. 0, mass%） have been developed. The effects of W on mechanical properties and corrosion resistance were investigated, and the microstructures were analyzed by optical microscopy, X-ray diffraction, transmission electron microscopy and electron backscatter diffraction. The designed steels have a balanced ferrite-austenite relation and are free of sigma phase after solution treatment at 750--1 300 ~C for 30 min followed by water-quenching, whereas a small number of Cr23 C~ precipitates were found after solution treatment at 750 ~C. After solution treatment at 1050 ℃, the steel with 1.8~ （mass percent） W exhibits the highest room temperature tensile strength due to the strongest work hardening effect, while the steel with 3.0% （mass percent） W exhibits the highest fracture elongation owing to the transformation-in- duced plasticity （TRIP） effect. The ductile-brittle transition （DBT） and martensite transformation are respectively found in the ferrite and austenite, which deteriorates the impact properties of the steels with the increase of W con- tent. The corrosion resistance of the designed steels is improved with the increase of W content. The pitting resistance of austenite is obviously better than that of ferrite for the designed alloys. Among the designed steels, the steel with 1.8% （mass percent） W is found to be an optimum steel with excellent comprehensive properties and lowest production cost.
