The FeZrB amorphous alloys for simulating the intergranular amorphous phase in the nanocrystalline Fe 89 Zr 7B 4 soft magnetic materials were obtained by mechanical alloying of a mixture of elemental Fe, Zr and ...The FeZrB amorphous alloys for simulating the intergranular amorphous phase in the nanocrystalline Fe 89 Zr 7B 4 soft magnetic materials were obtained by mechanical alloying of a mixture of elemental Fe, Zr and B powders for 25 h. It is shown that the Curie temperature of the simulated intergranular phase alloy is much lower than that of the intergranular phase with the same chemical composition in the nanocrystalline Fe 89 Zr 7B 4 alloy. The possible mechanism is mainly due to the strong ferromagnetic exchange force among the nanocrystalline α Fe grains.展开更多
An electrostatic reduced gravity device was developed and used specially for the study of the melt crystallization of polypropylene. The crystal structure of melt crystallized polypropylene prepared under the reduc...An electrostatic reduced gravity device was developed and used specially for the study of the melt crystallization of polypropylene. The crystal structure of melt crystallized polypropylene prepared under the reduced gravity environment was investigated by using X ray diffraction. The experiment results show that the crystal structure of the polypropylene is strongly dependent on the gravity applied to the sample during solidification. It is found that the crystallographic parameters a and b increase markedly with reduced gravity ratio, while the value of c increases mildly.展开更多
A new resource-saving duplex stainless steel with composition of 19Cr-6Mn-1.0Mo-0.5Ni-0.5W-0.5Cu-0.2N has been developed,and the microstructure,mechanical properties and corrosion properties have been investigated.The...A new resource-saving duplex stainless steel with composition of 19Cr-6Mn-1.0Mo-0.5Ni-0.5W-0.5Cu-0.2N has been developed,and the microstructure,mechanical properties and corrosion properties have been investigated.The results show that the alloy has a balanced ferrite-austenite relation,and the ferrite content rises with the solution treatment temperature.The designed alloy is free of precipitation of sigma phase when aged at 650,750 and 850 ℃ for 3 h,respectively,whereas a few Cr23C6 precipitates are found after being aged at 750 ℃ for 8 h.Charpy impact tests indicate that the impact energy of the alloy is 68,200 and 220 J at-40,0 and 25 ℃,respectively.The designed alloy solution treated at 1050 ℃ for 30 min has a much higher yield strength and similar corrosion resistance compared with those of AISI 304 austenitic stainless steel.Moreover,the production cost of the alloy is about $ 1000 per ton which is lower than that of AISI 304.展开更多
A new family of economical duplex stainless steels in which N or Mn was substituted for Ni with composi- tion of 22Cr-8.0Mn-xNi-1.0Mo-0.7Cu-0.7W-0.3N （x = 0.5 -- 2.0） have been developed by examining the micro- stru...A new family of economical duplex stainless steels in which N or Mn was substituted for Ni with composi- tion of 22Cr-8.0Mn-xNi-1.0Mo-0.7Cu-0.7W-0.3N （x = 0.5 -- 2.0） have been developed by examining the micro- structure, mechanical and corrosion properties of these alloys. The results show that these alloys have a balanced ferrite-austenite relation. In addition, the alloys are free of precipitation of sigma phase and Cr-nitride when solution- treated at 750 to 1300℃ for 30 min. The yield strength, tensile strength and fracture elongation values of experi- mental alloys solution-treated at 1050 ℃ for 30 min are about 500, 750 MPa and 40.0%, respectively. Low-temper- ature impact properties can be improved distinctly with the increase of nickel content. Among the designed DSS al- loys, the alloy with Ni of 2.0% is found to be an optimum alloy with proper phase proportion, better low-tempera- ture impact properties and higher pitting corrosion resistance compared with those o~ other alloys. The mechanical and corrosion properties and lower production cost of the designed DSSs are better than those of AISI 304.展开更多
A new family of resource saving, high chromium and manganese super duplex stainless steels （DSSs）, with a composition in mass percent, % of Cr 0.29, Mn 0.12, Ni 2.0, Mo i. 0, and N 0. 51-0. 68, has been developed by...A new family of resource saving, high chromium and manganese super duplex stainless steels （DSSs）, with a composition in mass percent, % of Cr 0.29, Mn 0.12, Ni 2.0, Mo i. 0, and N 0. 51-0. 68, has been developed by examining the effect of N on the microstructure, mechanical properties and corrosion properties. The results show that these alloys have a balanced ferrite-austenite relation. The austenite volume fraction decreases with the solution treatment temperature, but it increases with an increase in N content. The increases in nitrogen enhance the ultimate tensile strength （UTS） and reduce the ductility of the material slightly. The pitting corrosion potential increases first and then decreases with an increase in nitrogen content when the amount of N arrives to 0.68%. The yield stress and ultimate tensile strength of solution treated samples were more than 680 and 900 MPa, the elongation of experimental alloys are higher than 30%, respectively, what is more, the pitting potentials were beyond 1 100 mV.展开更多
文摘The FeZrB amorphous alloys for simulating the intergranular amorphous phase in the nanocrystalline Fe 89 Zr 7B 4 soft magnetic materials were obtained by mechanical alloying of a mixture of elemental Fe, Zr and B powders for 25 h. It is shown that the Curie temperature of the simulated intergranular phase alloy is much lower than that of the intergranular phase with the same chemical composition in the nanocrystalline Fe 89 Zr 7B 4 alloy. The possible mechanism is mainly due to the strong ferromagnetic exchange force among the nanocrystalline α Fe grains.
文摘An electrostatic reduced gravity device was developed and used specially for the study of the melt crystallization of polypropylene. The crystal structure of melt crystallized polypropylene prepared under the reduced gravity environment was investigated by using X ray diffraction. The experiment results show that the crystal structure of the polypropylene is strongly dependent on the gravity applied to the sample during solidification. It is found that the crystallographic parameters a and b increase markedly with reduced gravity ratio, while the value of c increases mildly.
基金Item Sponsored by Key Project of Science and Technology Commission of Shanghai Municipality of China(065211026)Innovation Fund of Education Commission of Shanghai Municipality of China(09yz20)
文摘A new resource-saving duplex stainless steel with composition of 19Cr-6Mn-1.0Mo-0.5Ni-0.5W-0.5Cu-0.2N has been developed,and the microstructure,mechanical properties and corrosion properties have been investigated.The results show that the alloy has a balanced ferrite-austenite relation,and the ferrite content rises with the solution treatment temperature.The designed alloy is free of precipitation of sigma phase when aged at 650,750 and 850 ℃ for 3 h,respectively,whereas a few Cr23C6 precipitates are found after being aged at 750 ℃ for 8 h.Charpy impact tests indicate that the impact energy of the alloy is 68,200 and 220 J at-40,0 and 25 ℃,respectively.The designed alloy solution treated at 1050 ℃ for 30 min has a much higher yield strength and similar corrosion resistance compared with those of AISI 304 austenitic stainless steel.Moreover,the production cost of the alloy is about $ 1000 per ton which is lower than that of AISI 304.
基金Sponsored by Innovation Fund of Education Commission of Shanghai Municipality of China (09yz20)
文摘A new family of economical duplex stainless steels in which N or Mn was substituted for Ni with composi- tion of 22Cr-8.0Mn-xNi-1.0Mo-0.7Cu-0.7W-0.3N （x = 0.5 -- 2.0） have been developed by examining the micro- structure, mechanical and corrosion properties of these alloys. The results show that these alloys have a balanced ferrite-austenite relation. In addition, the alloys are free of precipitation of sigma phase and Cr-nitride when solution- treated at 750 to 1300℃ for 30 min. The yield strength, tensile strength and fracture elongation values of experi- mental alloys solution-treated at 1050 ℃ for 30 min are about 500, 750 MPa and 40.0%, respectively. Low-temper- ature impact properties can be improved distinctly with the increase of nickel content. Among the designed DSS al- loys, the alloy with Ni of 2.0% is found to be an optimum alloy with proper phase proportion, better low-tempera- ture impact properties and higher pitting corrosion resistance compared with those o~ other alloys. The mechanical and corrosion properties and lower production cost of the designed DSSs are better than those of AISI 304.
基金Item Sponsored by Innovation Fund of Education Commission of Shanghai Municipality of China(09yz20)
文摘A new family of resource saving, high chromium and manganese super duplex stainless steels （DSSs）, with a composition in mass percent, % of Cr 0.29, Mn 0.12, Ni 2.0, Mo i. 0, and N 0. 51-0. 68, has been developed by examining the effect of N on the microstructure, mechanical properties and corrosion properties. The results show that these alloys have a balanced ferrite-austenite relation. The austenite volume fraction decreases with the solution treatment temperature, but it increases with an increase in N content. The increases in nitrogen enhance the ultimate tensile strength （UTS） and reduce the ductility of the material slightly. The pitting corrosion potential increases first and then decreases with an increase in nitrogen content when the amount of N arrives to 0.68%. The yield stress and ultimate tensile strength of solution treated samples were more than 680 and 900 MPa, the elongation of experimental alloys are higher than 30%, respectively, what is more, the pitting potentials were beyond 1 100 mV.
