In this paper, the synthesis process of TiC+TiN multiple films on super-low-carbon stainless steels is reported. The TiC layer is coated as the first layer in the multiple film, the change of growth rate of the film o...In this paper, the synthesis process of TiC+TiN multiple films on super-low-carbon stainless steels is reported. The TiC layer is coated as the first layer in the multiple film, the change of growth rate of the film on the 316L Stainless steel is not same as the one on carbides substrates, while the mole ratio of CRi to TiCLi (mCH/TiCl4) is changed from 1.2 to 2.0. The Ti [C, N], as a kind of inter-layer between TiC and TiN layers, is helpful to improve the adhesion between the TiC and TiN layer. The cooling rate greatly influences the quality of the adhesion between the TiC+TiN film and substrates.展开更多
The properties of the passive film formed on 2205 stainless steel in acetic acid at high temperature that contained chloride ions were studied by atomic absorption spectrometry （AAS）, X-ray photoelectron spectrosco...The properties of the passive film formed on 2205 stainless steel in acetic acid at high temperature that contained chloride ions were studied by atomic absorption spectrometry （AAS）, X-ray photoelectron spectroscopy （XPS）, and electrochemical polarization measurements. AAS results show that molybdenum is enriched on the surface as the passive film is dissolved. This enrichment decreases the corrosion resistance because it hinders chloride adsorption and Fe ion dissolution, and acts as a local pH buffer because it consumes protons. The dissolution ratio of Fe/Cr is approximately 10 during the active dissolution of the passive film. XPS results indicate that when the potential is in the passivation region, Cr comprises about 50% of the metal cations in the near-surface region of the passive film and is the main metal constituent in this region. When the polarization potential is much greater than the transpassivation potential, the Mo content accounts for approximately 45% of the metal cations in the nearurface region; Fe and Ni have no obvious influence on the formation, dissolution, or puncture of the passive film.展开更多
The current research of corrosion resistance of stainless steels mainly focuses on characterization of the passive films by point defect mode and mixed-conduction model. The corrosion resistance of the passive films f...The current research of corrosion resistance of stainless steels mainly focuses on characterization of the passive films by point defect mode and mixed-conduction model. The corrosion resistance of the passive films formed on asreceived and sensitized AISI304 stainless steel in borate bu er solution were evaluated in this paper. The degree of sensitization and corrosion resistance of AISI304 stainless steels was evaluated by double loop electrochemical potentiodynamic reactivation and electrochemical impedance spectroscopy. The passive films formed on the stainless steels were studied by XPS technique. It was found that as-received specimen had higher pitting corrosion potential and corrosion resistance than sensitized one. The Mott-Schottky results showed that sensitized stainless steel had more defects in the passive film than as-received one. The compositions of the passive films were mainly Cr and Fe oxides according to XPS results.展开更多
Tungsten films were deposited on stainless steel Charpy specimens by magnetron sputtering followed by electron beam heat treatment. Charpy impact tests and scanning electron microscopy were used to investigate the duc...Tungsten films were deposited on stainless steel Charpy specimens by magnetron sputtering followed by electron beam heat treatment. Charpy impact tests and scanning electron microscopy were used to investigate the ductile-brittle transition behavior of the specimens. With decreasing test temperature the fracture mode was transformed from ductile to brittle for both kinds of specimens with and without W films. The data of the crack initiation energy, crack propagation energy, impact absorbing energy, fracture time and deflection as well as the fracture morphologies at test temperature of -70℃ show that W films can improve the impact toughness of stainless steel.展开更多
The passive film formed on 2205 duplex stainless steel（DSS） in 0.5 M NaHCO3＋0.5 M NaCl aqueous solution was characterized by electrochemical measurements,including potentiodynamic anodic polarization and dynamic el...The passive film formed on 2205 duplex stainless steel（DSS） in 0.5 M NaHCO3＋0.5 M NaCl aqueous solution was characterized by electrochemical measurements,including potentiodynamic anodic polarization and dynamic electrochemical impedance spectroscopy（DEIS）.The results demonstrate that there is a great difference between the passive film evolutions of ferrite and austenite.The impedance values of ferrite are higher than those of austenite.The impedance peaks of ferritic and austenitic phases correspond to the potential of 0.15 and 0.25 V in the low potential range and correspond to 0.8 and 0.75 V in the high potential range.The evolutions of the capacitance of both phases are reverse compared to the evolutions of impedance.The thickness variations obtained from capacitance agree well with those of impedance analysis.The results can be used to explain why pitting corrosion occurs more easily in austenite phase than in ferrite phase.展开更多
Free-standing diamond films have been successfully deposited on stainless steel substrates using microwave plasma-assisted chemical vapor deposition. Although iron, which is the main element of stainless steel, is kno...Free-standing diamond films have been successfully deposited on stainless steel substrates using microwave plasma-assisted chemical vapor deposition. Although iron, which is the main element of stainless steel, is known to inhibit the nucleation of diamond and enhance the formation of graphite, we were able to grow relatively thick films （-1.2 mm）. The films were easily detachable from the substrates. The poor adhesion made it possible to obtain free-standing diamond films without chemical etching. Raman spectroscopy showed the 1332 cm^-1 characteristic Raman peak of diamond and the 1580 cm^-1, 1350 cm^-1 bands of graphite on the growth surface and backside of the films, respectively. By energy dispersive X-ray spectroscopy it was only possible to detect iron on the back of the films, but not on the surface. The role of iron in the film growth is discussed.展开更多
Stainies steel 30M was treated with the triangle-wave current method to form a different thickness colour film on the surface. The relationship between pitting potential and film thickness. effect of pitting on bright...Stainies steel 30M was treated with the triangle-wave current method to form a different thickness colour film on the surface. The relationship between pitting potential and film thickness. effect of pitting on brightnes (L). psychometnc chroma (a. b). and topography of coloured film were investigated in 3.5% NaCl solution. The relationship between film thickness (X) and pitting potential (Y) is basically linear as expressed by the equation:Y=164.96+0. 16X. R^=0.展开更多
This paper describes effects of 40 kHz ultrasound on the oxide films of stainless steel in sulphate electrolytes so as to determine the transmitted power and to characterize mass transfer and peak current density on t...This paper describes effects of 40 kHz ultrasound on the oxide films of stainless steel in sulphate electrolytes so as to determine the transmitted power and to characterize mass transfer and peak current density on the electrode surface. Emphasis was mainly laid on electrochemical oxidations and peeling mechanism of oxide films in sonicated sulphate solutions （0.5 and 1.0 mol/L）. Polarization voltammetry, current response traces and SEM analysis were carded out in order to provide full information as to oxide films surface. Results shows that the rate of electrochemical oxidation, the shape of polarization curves and the surface micrographs in sonicated sulphate electrolytes are different from those obtained without introduction of ultrasound. It is concluded that ultrasound can change the electro-chemical behavior of oxide films by its cavitaion effects, which would produce transient mechanical impulsive force and enhance electrochemical reactions.展开更多
Polyaniline (PANI) film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte. The potential sweep rates were changed to achieve the PANI film with dif...Polyaniline (PANI) film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte. The potential sweep rates were changed to achieve the PANI film with different thickness and structures. Protective properties of the PANI film for corrosion of stainless steel in 3% NaCl aqueous solution were investigated by monitoring potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that the PANI film which was formed with lower sweep rate led to more positive shift of corrosion potential and greater charge transfer resistance, reflecting higher inhibition for corrosion of the stainless steel.展开更多
A simple surface treatment was used to develop photocatalytic activity for stainless steel. AISI 304 stainless steel specimens after anodization were implanted by Ti ions at an extracting voltage of 50 kV with an impl...A simple surface treatment was used to develop photocatalytic activity for stainless steel. AISI 304 stainless steel specimens after anodization were implanted by Ti ions at an extracting voltage of 50 kV with an implantation dose of 3 × 10^15 atoms.cm-2 and then annealed in air at 450℃ for 2 h. The morphology was observed by scanning electron microscopy. The microstructure was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The photocatalytic degradation of methylene blue solution was carried out under ultraviolet light. The corrosion resistance of the stainless steel was evaluated in NaCl solution （3.5 wt%） by electrochemical polarization curves. It is found that the Ti ions depth profile resembles a Gaussian distribution in the implanted layer. The nanostructured Fe203/TiO2 composite film exhibits a remarkable enhancement in photocatalytic activity referenced to the mechanically polished specimen and anodized specimen. Meanwhile, the annealed Ti-implanted specimen remains good corrosion resistance.展开更多
The surface films on the Si-bearing stainless steels formed after soaking in the concentrated nitric acid for 216 h have been investigated by means of an electron energy spectrometer.It can he reached that Si builds u...The surface films on the Si-bearing stainless steels formed after soaking in the concentrated nitric acid for 216 h have been investigated by means of an electron energy spectrometer.It can he reached that Si builds up in the surface in the form of SiO_2.It plays a main part as a passivating element in the Si-bearing stainless steels in strong oxidizing medium,whereas Cr drops down to the second place.展开更多
The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an en...The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an energy dispersive analytical X ray system(SEM/EDAX). The experimental results show that the oxide scale growing on Fe26Cr1Mo exposed at 900 ℃ spalled severely during cooling, while after the stainless steel was coated with the Ni La 2O 3 electrodeposited composite film, its high temperature cyclic oxidation resistance was significantly improved. The reason is that a La 2O 3 modified NiO scale, which has a superior adhesion to the substrate, was formed on the Fe26Cr1Mo stainless steel coated with Ni La 2O 3 composite film.展开更多
In this paper, the cross sectional microstructure and crystal structure of ion plated multi layer films of stainless steel (1Cr18Ni9Ti ) were studied by cross sectional transmission electron microscopy (XTEM). The re...In this paper, the cross sectional microstructure and crystal structure of ion plated multi layer films of stainless steel (1Cr18Ni9Ti ) were studied by cross sectional transmission electron microscopy (XTEM). The results show that ion plated stainless steel multi layer films are fine grained double phase steel films of austenites and ferrites.Cross section film growing microstructures can be divided into three zones: fine equiaxed crystals, fine columnar crystals and coarse columnar crystals. Interfaces in multi layer films can promote fine grained growing and interrupt columnar grained growing,and improve properties of film materials.展开更多
Spectrally selective glazing system attracts great attention for energy efficient radiator applications. The present work reports the possibility of a specific shield (Stainless steel/Borosilicate glass) to provide pa...Spectrally selective glazing system attracts great attention for energy efficient radiator applications. The present work reports the possibility of a specific shield (Stainless steel/Borosilicate glass) to provide passive cooling for the purpose of reducing the use of classical active method. Radiative cooling devices require a convective shield that blocks all incoming solar radiation, but should selectively reemit radiation in the “atmospheric-window” region. In this study, borosilicate glass substrate coated with a stainless steel thin film was prepared by thermal evaporation and low pressure (6.3 × 10<sup>-3</sup> bar) DC plasma sputtering, in order to achieve the radiative cooling effect. The optical properties of the optimal thickness thin film were measured in the wavelength range of 0.3-20 μm by an OL-750 double-beam spectroradiometer. The thin film has high visible band reflectance with high infrared band emissivity across the full 8-13 μm;which indicates that stainless steel thin film can be used as good radiative cooling material.展开更多
文摘In this paper, the synthesis process of TiC+TiN multiple films on super-low-carbon stainless steels is reported. The TiC layer is coated as the first layer in the multiple film, the change of growth rate of the film on the 316L Stainless steel is not same as the one on carbides substrates, while the mole ratio of CRi to TiCLi (mCH/TiCl4) is changed from 1.2 to 2.0. The Ti [C, N], as a kind of inter-layer between TiC and TiN layers, is helpful to improve the adhesion between the TiC and TiN layer. The cooling rate greatly influences the quality of the adhesion between the TiC+TiN film and substrates.
基金the National Natural Science Foundation of China (No.50871020)
文摘The properties of the passive film formed on 2205 stainless steel in acetic acid at high temperature that contained chloride ions were studied by atomic absorption spectrometry （AAS）, X-ray photoelectron spectroscopy （XPS）, and electrochemical polarization measurements. AAS results show that molybdenum is enriched on the surface as the passive film is dissolved. This enrichment decreases the corrosion resistance because it hinders chloride adsorption and Fe ion dissolution, and acts as a local pH buffer because it consumes protons. The dissolution ratio of Fe/Cr is approximately 10 during the active dissolution of the passive film. XPS results indicate that when the potential is in the passivation region, Cr comprises about 50% of the metal cations in the near-surface region of the passive film and is the main metal constituent in this region. When the polarization potential is much greater than the transpassivation potential, the Mo content accounts for approximately 45% of the metal cations in the nearurface region; Fe and Ni have no obvious influence on the formation, dissolution, or puncture of the passive film.
基金supported by National Key Research and Development Program of China(No.2016YFF0203301,2016YFF0203305 and 2017YFF0210002)National Natural Science Foundation of China(No.U1537212)
文摘The current research of corrosion resistance of stainless steels mainly focuses on characterization of the passive films by point defect mode and mixed-conduction model. The corrosion resistance of the passive films formed on asreceived and sensitized AISI304 stainless steel in borate bu er solution were evaluated in this paper. The degree of sensitization and corrosion resistance of AISI304 stainless steels was evaluated by double loop electrochemical potentiodynamic reactivation and electrochemical impedance spectroscopy. The passive films formed on the stainless steels were studied by XPS technique. It was found that as-received specimen had higher pitting corrosion potential and corrosion resistance than sensitized one. The Mott-Schottky results showed that sensitized stainless steel had more defects in the passive film than as-received one. The compositions of the passive films were mainly Cr and Fe oxides according to XPS results.
文摘Tungsten films were deposited on stainless steel Charpy specimens by magnetron sputtering followed by electron beam heat treatment. Charpy impact tests and scanning electron microscopy were used to investigate the ductile-brittle transition behavior of the specimens. With decreasing test temperature the fracture mode was transformed from ductile to brittle for both kinds of specimens with and without W films. The data of the crack initiation energy, crack propagation energy, impact absorbing energy, fracture time and deflection as well as the fracture morphologies at test temperature of -70℃ show that W films can improve the impact toughness of stainless steel.
基金supported by the National Natural Science Foundation of China(No.50871020)
文摘The passive film formed on 2205 duplex stainless steel（DSS） in 0.5 M NaHCO3＋0.5 M NaCl aqueous solution was characterized by electrochemical measurements,including potentiodynamic anodic polarization and dynamic electrochemical impedance spectroscopy（DEIS）.The results demonstrate that there is a great difference between the passive film evolutions of ferrite and austenite.The impedance values of ferrite are higher than those of austenite.The impedance peaks of ferritic and austenitic phases correspond to the potential of 0.15 and 0.25 V in the low potential range and correspond to 0.8 and 0.75 V in the high potential range.The evolutions of the capacitance of both phases are reverse compared to the evolutions of impedance.The thickness variations obtained from capacitance agree well with those of impedance analysis.The results can be used to explain why pitting corrosion occurs more easily in austenite phase than in ferrite phase.
文摘Free-standing diamond films have been successfully deposited on stainless steel substrates using microwave plasma-assisted chemical vapor deposition. Although iron, which is the main element of stainless steel, is known to inhibit the nucleation of diamond and enhance the formation of graphite, we were able to grow relatively thick films （-1.2 mm）. The films were easily detachable from the substrates. The poor adhesion made it possible to obtain free-standing diamond films without chemical etching. Raman spectroscopy showed the 1332 cm^-1 characteristic Raman peak of diamond and the 1580 cm^-1, 1350 cm^-1 bands of graphite on the growth surface and backside of the films, respectively. By energy dispersive X-ray spectroscopy it was only possible to detect iron on the back of the films, but not on the surface. The role of iron in the film growth is discussed.
文摘Stainies steel 30M was treated with the triangle-wave current method to form a different thickness colour film on the surface. The relationship between pitting potential and film thickness. effect of pitting on brightnes (L). psychometnc chroma (a. b). and topography of coloured film were investigated in 3.5% NaCl solution. The relationship between film thickness (X) and pitting potential (Y) is basically linear as expressed by the equation:Y=164.96+0. 16X. R^=0.
文摘This paper describes effects of 40 kHz ultrasound on the oxide films of stainless steel in sulphate electrolytes so as to determine the transmitted power and to characterize mass transfer and peak current density on the electrode surface. Emphasis was mainly laid on electrochemical oxidations and peeling mechanism of oxide films in sonicated sulphate solutions （0.5 and 1.0 mol/L）. Polarization voltammetry, current response traces and SEM analysis were carded out in order to provide full information as to oxide films surface. Results shows that the rate of electrochemical oxidation, the shape of polarization curves and the surface micrographs in sonicated sulphate electrolytes are different from those obtained without introduction of ultrasound. It is concluded that ultrasound can change the electro-chemical behavior of oxide films by its cavitaion effects, which would produce transient mechanical impulsive force and enhance electrochemical reactions.
文摘Polyaniline (PANI) film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte. The potential sweep rates were changed to achieve the PANI film with different thickness and structures. Protective properties of the PANI film for corrosion of stainless steel in 3% NaCl aqueous solution were investigated by monitoring potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that the PANI film which was formed with lower sweep rate led to more positive shift of corrosion potential and greater charge transfer resistance, reflecting higher inhibition for corrosion of the stainless steel.
基金financially supported by the National Natural Science Foundation of China (Nos. 50771075 and51171133)the Program for New Century Excellent Talents in Universities (No. NCET-07-0650)The Cooperation Project in Industry,Education and Research of Guangdong Province and the Ministry of Education of China (No. 2011B090400334)
文摘A simple surface treatment was used to develop photocatalytic activity for stainless steel. AISI 304 stainless steel specimens after anodization were implanted by Ti ions at an extracting voltage of 50 kV with an implantation dose of 3 × 10^15 atoms.cm-2 and then annealed in air at 450℃ for 2 h. The morphology was observed by scanning electron microscopy. The microstructure was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The photocatalytic degradation of methylene blue solution was carried out under ultraviolet light. The corrosion resistance of the stainless steel was evaluated in NaCl solution （3.5 wt%） by electrochemical polarization curves. It is found that the Ti ions depth profile resembles a Gaussian distribution in the implanted layer. The nanostructured Fe203/TiO2 composite film exhibits a remarkable enhancement in photocatalytic activity referenced to the mechanically polished specimen and anodized specimen. Meanwhile, the annealed Ti-implanted specimen remains good corrosion resistance.
文摘The surface films on the Si-bearing stainless steels formed after soaking in the concentrated nitric acid for 216 h have been investigated by means of an electron energy spectrometer.It can he reached that Si builds up in the surface in the form of SiO_2.It plays a main part as a passivating element in the Si-bearing stainless steels in strong oxidizing medium,whereas Cr drops down to the second place.
文摘The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an energy dispersive analytical X ray system(SEM/EDAX). The experimental results show that the oxide scale growing on Fe26Cr1Mo exposed at 900 ℃ spalled severely during cooling, while after the stainless steel was coated with the Ni La 2O 3 electrodeposited composite film, its high temperature cyclic oxidation resistance was significantly improved. The reason is that a La 2O 3 modified NiO scale, which has a superior adhesion to the substrate, was formed on the Fe26Cr1Mo stainless steel coated with Ni La 2O 3 composite film.
文摘In this paper, the cross sectional microstructure and crystal structure of ion plated multi layer films of stainless steel (1Cr18Ni9Ti ) were studied by cross sectional transmission electron microscopy (XTEM). The results show that ion plated stainless steel multi layer films are fine grained double phase steel films of austenites and ferrites.Cross section film growing microstructures can be divided into three zones: fine equiaxed crystals, fine columnar crystals and coarse columnar crystals. Interfaces in multi layer films can promote fine grained growing and interrupt columnar grained growing,and improve properties of film materials.
文摘Spectrally selective glazing system attracts great attention for energy efficient radiator applications. The present work reports the possibility of a specific shield (Stainless steel/Borosilicate glass) to provide passive cooling for the purpose of reducing the use of classical active method. Radiative cooling devices require a convective shield that blocks all incoming solar radiation, but should selectively reemit radiation in the “atmospheric-window” region. In this study, borosilicate glass substrate coated with a stainless steel thin film was prepared by thermal evaporation and low pressure (6.3 × 10<sup>-3</sup> bar) DC plasma sputtering, in order to achieve the radiative cooling effect. The optical properties of the optimal thickness thin film were measured in the wavelength range of 0.3-20 μm by an OL-750 double-beam spectroradiometer. The thin film has high visible band reflectance with high infrared band emissivity across the full 8-13 μm;which indicates that stainless steel thin film can be used as good radiative cooling material.
