The aging properties of Cu-0.35Cr-0.038Zr-0.055Ce alloy are studied. The results show that can obtain higher electrical conductivity and microhardness after solutioned at 920°Cfor Ih, and aged at 500°C. The ...The aging properties of Cu-0.35Cr-0.038Zr-0.055Ce alloy are studied. The results show that can obtain higher electrical conductivity and microhardness after solutioned at 920°Cfor Ih, and aged at 500°C. The process of precipitation of the secondary phase can be accelerated with cold deformation before aging, so properties of the alloy are improved. Upon aging at 500°C for 30 minutes after 60% cold deformation, the values of electrical conductivity and microhardness are 69.0%IACS and 152HV respectively, but they are only 66.2%IACS and 136HV upon directly aging after solution. With the addition of a trace of rare earth element Ce, the value of microhardness of Cu-0.35Cr-0.038Zr alloy increases 18-25HV, while the value of electrical conductivity drops a little.展开更多
A martensitic microalloyed steel, 25Si2MnCrMo, was developed to meet the demands of the high-strength bars. Microstructure and mechanical properties of the steel were evaluated by using optical metallography, scanning...A martensitic microalloyed steel, 25Si2MnCrMo, was developed to meet the demands of the high-strength bars. Microstructure and mechanical properties of the steel were evaluated by using optical metallography, scanning electron microscopy, transmission electron microscopy, dilatometry and tensometry. Those measurements suggested that the steel consisted of martensite and retained austenite, which existed between the martensitic laths in a stable thin film, and that the steel showed very high tensile strength of 1400 MPa and good ductility of 15% in elongation after 300°C tempering.展开更多
Four 2-(α-hydroxyalkyl)-2-oxazolines and a 2-(α-hydroxy-α,α-diphenyl)-2-benzooxazole were synthesized from β-amimoalcohols and α-hydroxy carboxylic acids under microwave irradiation in the absence of a solvent.
Ni-Fe-C filler metal based on WC-30Co/Ni-Fe-C/45 steel is developed using TIGwelding method. The weld joints are studied by means of optical microscope, SEM, EPMA, X-rays andmicro hardness test etc. The results show t...Ni-Fe-C filler metal based on WC-30Co/Ni-Fe-C/45 steel is developed using TIGwelding method. The weld joints are studied by means of optical microscope, SEM, EPMA, X-rays andmicro hardness test etc. The results show that the weld joints of WC-30Co and 45 steel can beobtained by TIG welding using Ni-Fe-C alloys as filler metals. The harmful eta phase formed in thejoints is M_6C, M_(12)C type carbides. The poor carbon content of the W-Co-C system resulted fromthe carbon diffusion and the high ingredient Fe are the two vital factors inducing to eta phaseformation. It could be restricted by the addition of carbon element into Ni-Fe alloys.展开更多
基金supported by the National 863 Plan Items of China(No.2002AA331112)
文摘The aging properties of Cu-0.35Cr-0.038Zr-0.055Ce alloy are studied. The results show that can obtain higher electrical conductivity and microhardness after solutioned at 920°Cfor Ih, and aged at 500°C. The process of precipitation of the secondary phase can be accelerated with cold deformation before aging, so properties of the alloy are improved. Upon aging at 500°C for 30 minutes after 60% cold deformation, the values of electrical conductivity and microhardness are 69.0%IACS and 152HV respectively, but they are only 66.2%IACS and 136HV upon directly aging after solution. With the addition of a trace of rare earth element Ce, the value of microhardness of Cu-0.35Cr-0.038Zr alloy increases 18-25HV, while the value of electrical conductivity drops a little.
文摘A martensitic microalloyed steel, 25Si2MnCrMo, was developed to meet the demands of the high-strength bars. Microstructure and mechanical properties of the steel were evaluated by using optical metallography, scanning electron microscopy, transmission electron microscopy, dilatometry and tensometry. Those measurements suggested that the steel consisted of martensite and retained austenite, which existed between the martensitic laths in a stable thin film, and that the steel showed very high tensile strength of 1400 MPa and good ductility of 15% in elongation after 300°C tempering.
文摘Four 2-(α-hydroxyalkyl)-2-oxazolines and a 2-(α-hydroxy-α,α-diphenyl)-2-benzooxazole were synthesized from β-amimoalcohols and α-hydroxy carboxylic acids under microwave irradiation in the absence of a solvent.
文摘Ni-Fe-C filler metal based on WC-30Co/Ni-Fe-C/45 steel is developed using TIGwelding method. The weld joints are studied by means of optical microscope, SEM, EPMA, X-rays andmicro hardness test etc. The results show that the weld joints of WC-30Co and 45 steel can beobtained by TIG welding using Ni-Fe-C alloys as filler metals. The harmful eta phase formed in thejoints is M_6C, M_(12)C type carbides. The poor carbon content of the W-Co-C system resulted fromthe carbon diffusion and the high ingredient Fe are the two vital factors inducing to eta phaseformation. It could be restricted by the addition of carbon element into Ni-Fe alloys.
