摘要:
A zinc-based metal plated steel sheet is excellent in tribological properties during press forming. An oxide layer containing crystalline 3Zn(OH)2.ZnSO4. xH2O is formed on a plated surface. The oxide layer has a thickness of 10 nm or more. The crystalline oxide layer is composed of 3Zn(OH)2.ZnSO4.3-5H2O.
摘要:
A method for producing a galvanized steel sheet includes contacting a steel sheet with a zinc-containing aqueous solution having a zinc ion concentration of 1 to 100 g/l, contacting the steel sheet with an aqueous solution with a pH of 6 to 14, washing the steel sheet with water, and then drying the steel sheet. An example of the zinc-containing aqueous solution is a solution containing zinc sulfate. According to the method, an oxide layer which has an average thickness of 10 nm or more and which principally contains zinc is formed on the steel sheet and the galvanized steel sheet can be stably produced at high speed in a reduced space so as to have excellent press formability.
摘要:
A zinc-based metal plated steel sheet is excellent in tribological properties during press forming. An oxide layer containing crystalline 3Zn(OH)2.ZnSO4.xH2O is formed on a plated surface. The oxide layer has a thickness of 10 nm or more. The crystalline oxide layer is composed of 3Zn(OH)2.ZnSO4.3-5H2O.
摘要:
A zinc-based metal plated steel sheet is excellent in tribological properties during press forming. An oxide layer containing crystalline 3Zn(OH)2·ZnSO4·xH2O is formed on a plated surface. The oxide layer has a thickness of 10 nm or more. The crystalline oxide layer is composed of 3Zn(OH)2·ZnSO4·3-5H2O.
摘要:
A zinc-based metal plated steel sheet is excellent in tribological properties during press forming. An oxide layer containing crystalline 3Zn(OH)2.ZnSO4.xH2O is formed on a plated surface. The oxide layer has a thickness of 10 nm or more. The crystalline oxide layer is composed of 3Zn(OH)2.ZnSO4.3-5H2O.
摘要:
A method for manufacturing a galvanized steel sheet, includes: galvanizing a steel sheet; bringing the surface of the steel sheet into contact with an aqueous solution containing zinc ion in the range of 5 to 100 g/l as the zinc ion concentration, having a pH of 4 to 6, and having a liquid temperature of 20 to 70° C., holding the steel sheet for 1 to 60 seconds; and then washing and drying the steel sheet. The solution containing zinc is preferably one containing zinc sulfate, for example. According to the method, a galvanized steel sheet having an oxide layer having an average thickness of 10 nm or more and mainly containing zinc formed on the surface of the steel sheet and having excellent press formability can be stably manufactured in a short time.
摘要:
A hot-pressed member includes a steel sheet, a Ni-diffusion region present in a surface layer of the steel sheet, and an intermetallic compound layer and a ZnO layer which are provided in order on the Ni-diffusion region, the intermetallic compound layer corresponding to a γ phase present in a phase equilibrium diagram of a Zn—Ni alloy, wherein a spontaneous immersion potential indicated in a 0.5 M NaCl aqueous air-saturated solution at 25° C.±5° C. is −600 to −360 mV based on a standard hydrogen electrode.
摘要:
A hot-pressed member includes a steel sheet, a Ni-diffusion region present in a surface layer of the steel sheet, and an intermetallic compound layer and a ZnO layer which are provided in order on the Ni-diffusion region, the intermetallic compound layer corresponding to a γ phase present in a phase equilibrium diagram of a Zn—Ni alloy, wherein a spontaneous immersion potential indicated in a 0.5 M NaCl aqueous air-saturated solution at 25° C.±5° C. is −600 to −360 mV based on a standard hydrogen electrode.
摘要:
A method of manufacturing a hot dip galvannealed steel sheet, including the steps of: subjecting a steel sheet to hot dip galvanizing to manufacture a hot dip galvanized steel sheet; heating the hot dip galvanized steel sheet for alloying; subjecting the hot dip galvanized steel sheet to temper rolling; bringing the temper-rolled hot dip galvanized steel sheet into contact with an acid solution containing at least one ion selected from the group consisting of Zr ions, Ti ions, and Sn ions to thereby form an acid solution film on the surface of the steel sheet; after completion of the contact, a state where the acid solution film is formed on the surface of the steel sheet is held for at least 1 second; and washing with water the hot dip galvanized steel sheet after holding, to thereby form a Zn oxide layer having a thickness of 10 nm or more on the surface of the galvanized steel sheet. The hot dip galvannealed steel sheet has an oxide layer having an average thickness of 10 nm or more on the surface of the plated steel sheet.
摘要:
A hot dip Al—Zn coated steel sheet exhibits excellent corrosion resistance. The Al content in a coated film is 20-95% by mass. The Ca content is 0.01-10% by mass. Alternatively, the total content of Ca and Mg is 0.01-10% by mass. Preferably, the coated film includes an upper layer and an alloy phase present at the interface to a substrate steel sheet, and Ca or Ca and Mg are contained primarily in the upper layer. Also preferably, the Ca or Ca and Mg include an intermetallic compound with at least one type selected from Zn, Al, and Si. If Ca or Ca and Mg are contained in the coated film, as described above, these elements are contained in corrosion products generated in a bonded portion and exert effects of stabilizing the corrosion products and retarding proceeding of corrosion thereafter. Then, as a result, the corrosion resistance is improved.