摘要:
Provided is a method for manufacturing a high-strength galvanized steel sheet, made from a steel sheet containing Si and/or Mn, having excellent exfoliation resistance during heavy machining. When a steel sheet containing 0.01% to 0.18% C, 0.02% to 2.0% Si, 1.0% to 3.0% Mn, 0.001% to 1.0% Al, 0.005% to 0.060% P, and 0.01% or less S on a mass basis, the remainder being Fe and unavoidable impurities, is annealed and galvanized in a continuous galvanizing line, a temperature region with a furnace temperature of A° C. to B° C. (600≦A≦780 and 800≦B≦900) is performed at an atmosphere dew-point temperature of −5° C. or higher in a heating process.
摘要:
Provided is a method for manufacturing a high-strength galvanized steel sheet, made from a steel sheet containing Si and/or Mn, having excellent exfoliation resistance during heavy machining. When a steel sheet containing 0.01% to 0.18% C, 0.02% to 2.0% Si, 1.0% to 3.0% Mn, 0.001% to 1.0% Al, 0.005% to 0.060% P, and 0.01% or less S on a mass basis, the remainder being Fe and unavoidable impurities, is annealed and galvanized in a continuous galvanizing line, a temperature region with a furnace temperature of A° C. to B° C. (600≦A≦780 and 800≦B≦900) is performed at an atmosphere dew-point temperature of −5° C. or higher in a heating process.
摘要:
A high-strength galvanized steel sheet having excellent formability contains as a chemical component of steel on a mass percent basis: 0.05% to 0.3% of C; more than 0.60% to 2.0% of Si; 0.50% to 3.50% of Mn; 0.003% to 0.100% of P; 0.010% or less of S; 0.010% to 0.06% of Al; 0.007% or less of N; and the balance including Fe and inevitable impurities, and in the microstructure of the steel sheet, the standard deviation of nano-hardness is 1.50 GPa or less.
摘要:
A method for manufacturing a high strength hot-dip galvanized steel sheet includes: heating a steel sheet in a CGL, the steel sheet including on a mass percent basis, as chemical components, 0.005% to 0.12% of C, 0.7% to 1.8% of Si, 0.5% to 2.8% of Mn, 0.1% or less of P, 0.07% or less of S, 1.0% or less of Al, 0.008% or less of N, and the balance being Fe and incidental impurities; annealing at 700-940° C. for 15-600 seconds; cooling to 440-550° C. at 3° C./s or more; dipping the steel sheet at 440-550° C. into a hot-dip galvanizing bath at a temperature of 440 to 500° C. for 200 seconds or less to perform hot-dip galvanizing. By the method described above, a high strength hot-dip galvanized steel sheet having a tensile strength level of 590 MPa, which has good coating appearance and superior formability, is obtained.
摘要:
A method for producing a high-strength hot-dip galvanized steel sheet includes a steel sheet containing, in percent by mass, 0.01% to 0.18% of C, 0.02% to 2.0% of Si, 1.0% to 3.0% of Mn, 0.001% to 1.0% of Al, 0.005% to 0.060% of P, 0.01% or less of S, and the balance being Fe and incidental impurities, and a galvanized coating layer on each surface of the steel sheet with a coating weight of 20 to 120 g/m2 per surface, in which, when the steel sheet is subjected to annealing and a hot-dip galvanizing treatment in a continuous hot-dip galvanizing line, the dew point of the atmosphere is controlled to −40° C. or lower in the annealing furnace temperature range of 750° C. or higher.
摘要:
A method for producing a hot rolled steel sheet includes a slab heating step of heating a steel slab in a slab heating furnace, a step of hot-rolling the heated steel slab in a rough rolling mill to form a strip and a finish rolling mill, and a coiling step of coiling the strip around a coiler. The atmosphere in steps from the slab heating step to the coiling step is a non-oxidizing atmosphere. The slab steel contains C: 0.01-0.15%, Si: 0.1-1.8%, Mn: 1.0-2.7%, Al: 0.01-1.5%, P: 0.005-0.025%, and S: 0.01% or less, by mass. A hot-dip galvanized steel sheet is produced by pickling the hot rolled steel sheet to remove mill scale, or by pickling the sheet and further cold-rolling the sheet, and subsequently by subjecting the resultant to hot-dip galvanizing.
摘要:
A method for producing a high-strength hot-dip galvanized steel sheet includes a steel sheet containing, in percent by mass, 0.01% to 0.18% of C, 0.02% to 2.0% of Si, 1.0% to 3.0% of Mn, 0.001% to 1.0% of Al, 0.005% to 0.060% of P, 0.01% or less of S, and the balance being Fe and incidental impurities, and a galvanized coating layer on each surface of the steel sheet with a coating weight of 20 to 120 g/m2 per surface, in which, when the steel sheet is subjected to annealing and a hot-dip galvanizing treatment in a continuous hot-dip galvanizing line, the dew point of the atmosphere is controlled to −40° C. or lower in the annealing furnace temperature range of 750° C. or higher.
摘要:
A mobile body corrosion measuring apparatus having a corrosion sensor installed in at least one portion of a mobile body, the corrosion sensor measuring a corrosion state at the portion and outputting corrosion data; a vehicle (mobile body) running speed sensor installed in the mobile body, the running speed sensor measuring a running speed of the mobile body and outputting the running speed data; and a data collection unit that acquires the corrosion data from the corrosion sensor and the running speed data from the vehicle speed sensor at the same time and collects the corrosion data and the running speed data with the corrosion data and the running speed data associated with each other. Due to above structure, a corrosion state specific to the mobile body can be accurately measured.
摘要:
The invention provides a hot dip galvanized steel sheet which has: a hot dip galvanizing layer having a flat part on a surface thereof; and a film formed on the flat part. The film is composed of a compound containing Zn, Fe, and O, having an average film thickness A in a range from 10 to 100 nm determined by an element analysis of the film, and has {[Fe]/([Zn]+[Fe])} in the film in a range from 0.002 to 0.25, where [Zn] and [Fe] designate the content (% by atom) of Zn and Fe in the film, respectively. Since the hot dip galvanized steel sheet of the invention has excellent press-formability, bondability, and phosphatability, it is suitable for automobiles and electrical appliances.
摘要:
A galvanized steel sheet includes a basal steel sheet (BSS) containing C: 0.01-0.15%, Si: 0.001-2.0%, Mn: 0.1-3.0%, Al: 0.001-1.0%, P: 0.005-0.060%, and S≦0.01% (% by mass), balance Fe and unavoidable impurities, with zinc plating layers on both sides of the BSS. One or more oxides selected from Fe, Si, Mn, Al, and P oxides are in steel sheet superficial portions in direct contact with the zinc plating layers and extending from each surface of the BSS to 100 μm deep. A crystalline oxide is in the regions from each surface of the BSS to 10 μm depth, which are also located in direct contact with the zinc plating layers, the crystalline oxide including Fe crystal grains within which Si and Mn atoms are distributed in the regions from grain boundaries to 1 μm deep inside the grain.