Abstract: An aluminum or aluminum alloy-coated steel material includes base steel; and a coating layer formed on a surface of the base steel and containing by mass % Mg: 6% to 10%, Si: 3% to 7%, Fe: 0.2% to 2%, Mn: 0.02% to 2%, and the balance as Al and incidental impurities, wherein the coating layer has pseudoternary eutectic microstructures of ?Al—Mg2Si—(Al—Fe—Si—Mn) and an area ratio of the pseudoternary eutectic microstructures in the coating layer is at least 30%.

Abstract: A measuring apparatus is capable of measuring an amount of hydrogen penetrated into a metal. In the apparatus, a specimen formed of a metallic material has one surface exposed to a corrosive environment to serve as a penetration surface of hydrogen generated by a corrosion reaction while having the other surface as a hydrogen detection surface. On the hydrogen detection surface side, an electrochemical cell constituted of a plurality of cells is disposed. At least one of the plurality of cells is configured as a base cell to compensate for a residual current so that anodic currents detected in other cells than the base cell are compensated for based on the residual current detected in the base cell, and an amount of hydrogen penetrating from a corrosive surface side is calculated based on the compensated currents.

Abstract: An aluminum or aluminum alloy-coated steel material includes base steel; and a coating layer formed on a surface of the base steel and containing by mass % Mg: 6% to 10%, Si: 3% to 7%, Fe: 0.2% to 2%, Mn: 0.02% to 2%, and the balance as Al and incidental impurities, where-in the coating layer has pseudoternary eutectic microstructures of ?Al—Mg2Si—(Al—Fe—Si—Mn) and an area ratio of the pseudoternary eutectic microstructures in the coating layer is at least 30%.