NI Kequan CHEN Guoliang ZHU Ping XIA Haiping ** Dept.of Materials Science & Engineering
,
University of Science and Technology Beijing
,
Beijing
,
100083
,
China*** Shenzhen Jinyuan Stainless Steel Co.Ltd.
,
Shenzhen.518067
,
China+ To whom correspondence should be a
材料科学技术（英）
Using the calculation of thermodynamic equilibria in multicomponent systems,two ternary phase diagrams,Ni-Cr-Mo and Ni-Cr-Co,have been calculated by optimizing the Gibbs free ener- gies with respect to phase diagrams and thermodynamic data.On the basis of this calcula- tion,the occurrence of σ-phase in the residual solid solution of commercial Ni-base superalloys, IN-713C and U-700,has been predicted.The re- sults show that the calculation of phase equilibria is successful in the prediction of the occurrence of the σ-phase.
关键词:
thermodynamics
,
null
,
null
,
null
SUN Wenqiang
,
CAI Jiuju
,
MAO Hujun
,
GUAN Duojiao
钢铁研究学报(英文版)
As the largest energy consuming manufacturing sector and one of the most important sources of carbon dioxide (CO2) emissions, the China′s iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMDI) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emissions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.
关键词:
CO2 emissions
,
energy use
,
LMDI technique
,
steel production
,
energy consumption
Corrosion Science
A novel antibacterial stainless steel (ASS) with martenstic microstructure has been recently developed, by controlled copper ion implantation, as a new functional material having broad-spectrum antibacterial properties. The electrochemical corrosion behavior of the ASS in 0.05 mol/L NaCl was assessed using linear polarization and electrochemical impedance spectroscopy (EIS) and compared with that of a conventional stainless steel (SS) without copper ion implantation. The ASS exhibited higher corrosion susceptibility in the chloride medium; with a more negative (active) corrosion potential, higher anodic current density and lower charge transfer and polarization resistance. This has been attributed to the occurrence of copper-catalyzed interfacial reactions. A functional tool, 3-D presentation of EIS data, has been employed in analyzing the electrochemical corrosion processes as well as probing complex interfacial phenomena. (C) 2009 Published by Elsevier Ltd.
关键词:
Stainless steel;Copper;EIS;Polarization;Corrosion;sulfuric-acid;copper ions;cu;microstructure;resistance
Electrochimica Acta
Nanocrystallized (NC) 309 stainless steel (309SS) coating has been fabricated on glass substrate by DC magnetron sputtering. The coating, with an average grain size less than 50 nm, had ferritic (bcc) structure rather than the austenitic (fcc) structure of the bulk steel. The electrochemical corrosion behavior of the NC coating and the bulk steel in solutions of 0.25 M Na(2)SO(4) + 0.05 M H(2)SO(4) and 0.5 M NaCl + 0.05 M H(2)SO(4) was investigated by using potentiodynamic polarization, potentiostatic polarization and AC impedance techniques. The results showed that the corrosion behavior of the NC 309SS coating and 309SS bulk steel depended on the composition of the solutions. In the Na(2)SO(4) solution there was only a little difference between the corrosion resistance of the passive films on the NC coating and the bulk steel. However, in the solution with chloride ions, the localized corrosion resistance of 309SS was greatly enhanced by nanocrystallization due to the formation of a compact and stable passive film on the NC coating. The electronic structure of the passive film formed on the NC coating and on the bulk steel was analyzed by means of capacitance measurements, and a corrosion mechanism is proposed. (c) 2006 Published by Elsevier Ltd.
关键词:
nanocrystalline coating;309 stainless steel;localized corrosion;passive film;capacitance measurement;309l stainless-steels;passive films;electronic-structure;304-stainless-steel;resistance;breakdown;cr
材料科学技术（英）
BIOSS4 steel is essentially a nickel-free austenitic stainless steel developed by the Institute of Metal Research, Chinese Academy of Sciences, in response to nickel allergy problems associated with nickel-containing stainless steels that are widely used in medical applications. The high nitrogen content of this steel effectively maintains the austenitic stability and also contributes to the high levels of corrosion resistance and strength. BIOSS4 steel possesses a good combination of high strength and toughness, better corrosion resistance, and better blood compatibility, in comparison with the medical 316L stainless steel. Potential applications of BIOSS4 steel can include medical implantation material and orthodontic or orthopedic devices, as well as jewelries and other decorations.
关键词:
medical stainless steel;nitrogen;nickel-free;nickel-allergy;blood;compatibility;austenitic steels;high-nitrogen;corrosion;cells
Yibin REN
,
Ke YANG
,
Bingchun ZHANG
,
Yaqing WANG
,
Yong LIANG
材料科学技术（英）
BIOSS4 steel is essentially a nickel-free austenitic stainless steel developed by the Institute of Metal Research, Chinese Academy of Sciences, in response to nickel allergy problems associated with nickel-containing stainless steels that are widely used in medical applications. The high nitrogen content of this steel effectively maintains the austenitic stability and also contributes to the high levels of corrosion resistance and strength. BIOSS4 steel possesses a good combination of high strength and toughness, better corrosion resistance, and better blood compatibility, in comparison with the medical 316L stainless steel. Potential applications of BIOSS4 steel can include medical implantation material and orthodontic or orthopedic devices, as well as jewelries and other decorations.
关键词:
Medical stainless steel
,
null
,
null
,
null
,
null
Wear
The cavitation erosion (CE) behavior of two kinds of Cr-Mn-N stainless steels was investigated by means of an ultrasonic vibration processor and compared with that of 0Cr13Ni5Mo stainless steel, commonly used material for hydraulic turbines in China. The eroded surfaces after different CE duration were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Roughness (R-a) of the eroded surfaces was calculated from the measured profiles after different CE duration, and microhardness of cross-sections of the tested materials was also measured to indicate work-hardening ability. The results show that the CE resistance of austenitic single phase or austenite-ferrite duplex phase Cr-Mn-N steels is higher than that of the 0Cr13Ni5Mo martensitic stainless steel, which is mainly attributed to their high work-hardening ability. Different from 0Cr13Ni5Mo stainless steel, the cracks initiating in the eroded austenite of Cr-Mn-N stainless steels propagate nearly parallelly rather than normally to the surface, which is also beneficial to the resistance to CE. Low ferrite content is also found to be beneficial to improving the resistance to CE of duplex phase Cr-Mn-N stainless steels. It is supposed that in the case of Cr-Mn-N stainless steels the cavitation impingement energy could be absorbed and transferred into the inside of materials by the "forming and transferring" mode of the high hardness layer. Developing steel with high work-hardening ability and low ferrite volume content is possibly an important method to design steel with high CE resistance. (C) 2003 Elsevier Science B.V. All rights reserved.
关键词:
Cr-Mn-N stainless steels;cavitation erosion;ferrite content;mechanism;work-hardening;hydraulic turbines;resistance;duplex;alloys
Transactions of the Institute of Metal Finishing
A new process has been developed for colouring stainless steel. Various colour films could be obtained by using alternating voltage (AV) passivation in hot sulphuric acid solution. Unlike the INCO process, this process is operated in a bath containing no chromic acid, which is toxic to the environment. The desired colours can be obtained by adjusting the alternating electric field parameters. Corrosion tests show that the coloured film has a higher corrosion resistance than chemically coloured film. The coloured steel may be subjected to metal forming operations without detriment to the film; the coloured film also shows excellent wear resistance.
关键词:
stainless steel;colouring;corrosion resistance;green process;pulse;methods;passive film;304-stainless-steel
