With prices for metal resources such as nickel and molybdenum soaring,there is a heightened sense of crisis concerning resource scarcity.While Type304,the most common stainless steel,offers excellent corrosion resista...With prices for metal resources such as nickel and molybdenum soaring,there is a heightened sense of crisis concerning resource scarcity.While Type304,the most common stainless steel,offers excellent corrosion resistance,its price is affected significantly by the cost of nickel because of its 8%nickel content.The stainless steel that has the same corrosion resistance as that of Type304 and does not contain nickel and molybdenum has been required.JFE Steel Corporation has developed a new 21%Cr-0.4%Cu stainless steel,the world's first ferritic stainless steel,which offers equivalent corrosion resistance to Type304 while containing absolutely no nickel or molybdenum,two rare metals.The newly developed steel contains 21%chromium with the addition of 0.4% copper.The development of the steel is based on a new discovery that the passive films of stainless steels could be strengthened by the synergy effect of high chromium content and copper addition.Copper addition enriches the chromium content in passive films after field exposure.Newly developed 21%Cr-0.4%Cu stainless steel is adopted for many applications as a substitution for Type304,including commercial kitchenware,building materials and industrial machinery.The steel is expected to be a new standard of a ferritic stainless steel as a substitution for Type304.展开更多
A commercially pure titanium sheet with titanium carbide (TiC) precipitated in its surface layer was anodized in NH4NO3 aqueous solution and heat treated in air. The photocatalytic activity of titanium dioxide powder ...A commercially pure titanium sheet with titanium carbide (TiC) precipitated in its surface layer was anodized in NH4NO3 aqueous solution and heat treated in air. The photocatalytic activity of titanium dioxide powder collected from the surface of the anodized titanium sheet was evaluated under ultra-violet and visible light irradiation. It showed relatively high photocatalytic activity in 0.1 mol/l potassium iodide solution, which was almost equal to the activity level of TiO2 powder (P-25) manufactured by Degussa Corporation. The better photocatalytic activity under ultra-violet irradiation is considered to be related to the formation of anatase type titanium dioxide. Photocatalytic activity under visible light irradiation was also observed, which was considered to be attributable to impurity doping, (carbon), in the titanium dioxide powder.展开更多
Black-colored titanium was obtained by anodic oxidation of a commercially pure grade-1 titanium sheet in a 0.06 M NH4NO3 solution, followed by heat treatment at 773 K for 1 h in a vacuum furnace. The resulting oxide l...Black-colored titanium was obtained by anodic oxidation of a commercially pure grade-1 titanium sheet in a 0.06 M NH4NO3 solution, followed by heat treatment at 773 K for 1 h in a vacuum furnace. The resulting oxide layer on the titanium substrate was examined by X-ray photoelectron spectroscopy, X-ray diffraction, glow discharge spectroscopy, and scanning electron microscopy. It was found that the oxide layer on the black-colored titanium sheet was several micrometers thick and mainly consisted of rutile TiO2 exhibiting a sponge like nanoporous structure. It is considered that the black-colored appearance of the titanium sheet is due to the sponge like nanoporous structure of the oxide layer absorbing the incident light. The photocatalytic activity of the black-colored titanium sheet was examined by observing the decomposition of a methylene blue (MB, C16H18N3SCl) solution under ultraviolet irradiation due to the existence of rutile TiO2. The sheet also exhibited photocatalytic activity under visible light irradiation. It is believed that the photocatalytic response upon irradiation with white light is due to carbon doping of the titanium oxide layer on the titanium substrate.展开更多
A commercially pure titanium sheet precipitated TiC in the surface layer was fabricated by anodic oxidation in NH4NO3 solution and heat treatment in air. The fabricated sheet showed relatively high photocatalytic acti...A commercially pure titanium sheet precipitated TiC in the surface layer was fabricated by anodic oxidation in NH4NO3 solution and heat treatment in air. The fabricated sheet showed relatively high photocatalytic activity in 0.1 M KI solution, which was close to the activity level of the P-25 particle made by Degussa Corporation. It exhibited photocatalytic activity in antifungal and antivirus tests under black light irradiation. The better photocatalytic activity under black light irradiation is considered to be related to the formation of anatase and rutile type titanium dioxides and rough surface. It also showed photocatalytic activity under visible light irradiation, which is considered to be attributable to carbon and nitrogen doping in titanium dioxide.展开更多
Characteristic HSLA steels for automotive use are introduced in which both of precipitation and microstructure is controlled to obtain suitable mechanical properties.For outer panels such as fender,the combination of ...Characteristic HSLA steels for automotive use are introduced in which both of precipitation and microstructure is controlled to obtain suitable mechanical properties.For outer panels such as fender,the combination of low yield strength,high tensile strength and deep-drawability were realized by controlling the distribution of NbC and precipitation free zone.The other steel,developed for chassis parts such as lower arm,utilizes extremely fine interphase precipitation to obtain high yield strength and excellent hole expansionability.Both steels have contributed to the reduction of weight in car body.展开更多
文摘With prices for metal resources such as nickel and molybdenum soaring,there is a heightened sense of crisis concerning resource scarcity.While Type304,the most common stainless steel,offers excellent corrosion resistance,its price is affected significantly by the cost of nickel because of its 8%nickel content.The stainless steel that has the same corrosion resistance as that of Type304 and does not contain nickel and molybdenum has been required.JFE Steel Corporation has developed a new 21%Cr-0.4%Cu stainless steel,the world's first ferritic stainless steel,which offers equivalent corrosion resistance to Type304 while containing absolutely no nickel or molybdenum,two rare metals.The newly developed steel contains 21%chromium with the addition of 0.4% copper.The development of the steel is based on a new discovery that the passive films of stainless steels could be strengthened by the synergy effect of high chromium content and copper addition.Copper addition enriches the chromium content in passive films after field exposure.Newly developed 21%Cr-0.4%Cu stainless steel is adopted for many applications as a substitution for Type304,including commercial kitchenware,building materials and industrial machinery.The steel is expected to be a new standard of a ferritic stainless steel as a substitution for Type304.
文摘A commercially pure titanium sheet with titanium carbide (TiC) precipitated in its surface layer was anodized in NH4NO3 aqueous solution and heat treated in air. The photocatalytic activity of titanium dioxide powder collected from the surface of the anodized titanium sheet was evaluated under ultra-violet and visible light irradiation. It showed relatively high photocatalytic activity in 0.1 mol/l potassium iodide solution, which was almost equal to the activity level of TiO2 powder (P-25) manufactured by Degussa Corporation. The better photocatalytic activity under ultra-violet irradiation is considered to be related to the formation of anatase type titanium dioxide. Photocatalytic activity under visible light irradiation was also observed, which was considered to be attributable to impurity doping, (carbon), in the titanium dioxide powder.
文摘Black-colored titanium was obtained by anodic oxidation of a commercially pure grade-1 titanium sheet in a 0.06 M NH4NO3 solution, followed by heat treatment at 773 K for 1 h in a vacuum furnace. The resulting oxide layer on the titanium substrate was examined by X-ray photoelectron spectroscopy, X-ray diffraction, glow discharge spectroscopy, and scanning electron microscopy. It was found that the oxide layer on the black-colored titanium sheet was several micrometers thick and mainly consisted of rutile TiO2 exhibiting a sponge like nanoporous structure. It is considered that the black-colored appearance of the titanium sheet is due to the sponge like nanoporous structure of the oxide layer absorbing the incident light. The photocatalytic activity of the black-colored titanium sheet was examined by observing the decomposition of a methylene blue (MB, C16H18N3SCl) solution under ultraviolet irradiation due to the existence of rutile TiO2. The sheet also exhibited photocatalytic activity under visible light irradiation. It is believed that the photocatalytic response upon irradiation with white light is due to carbon doping of the titanium oxide layer on the titanium substrate.
文摘A commercially pure titanium sheet precipitated TiC in the surface layer was fabricated by anodic oxidation in NH4NO3 solution and heat treatment in air. The fabricated sheet showed relatively high photocatalytic activity in 0.1 M KI solution, which was close to the activity level of the P-25 particle made by Degussa Corporation. It exhibited photocatalytic activity in antifungal and antivirus tests under black light irradiation. The better photocatalytic activity under black light irradiation is considered to be related to the formation of anatase and rutile type titanium dioxides and rough surface. It also showed photocatalytic activity under visible light irradiation, which is considered to be attributable to carbon and nitrogen doping in titanium dioxide.
文摘Characteristic HSLA steels for automotive use are introduced in which both of precipitation and microstructure is controlled to obtain suitable mechanical properties.For outer panels such as fender,the combination of low yield strength,high tensile strength and deep-drawability were realized by controlling the distribution of NbC and precipitation free zone.The other steel,developed for chassis parts such as lower arm,utilizes extremely fine interphase precipitation to obtain high yield strength and excellent hole expansionability.Both steels have contributed to the reduction of weight in car body.
