Provided is a stainless steel substrate for a solar cell, the stainless steel substrate including, by mass %, Cr: 9% to 25%, C: 0.03% or less, Mn: 2% or less, P: 0.05% or less, S: 0.01% or less, N: 0.03% or less, Al: 0.005% to 5.0%, Si: 0.05% to 4.0%, and a remainder including Fe and unavoidable impurities, in which an oxide film containing (i) Al.sub.2O.sub.3 in an amount of 50% or more or containing (i) Al.sub.2O.sub.3 and (ii) SiO.sub.2 in a total amount of 50% or more is formed on a surface of stainless steel having a composition which contains Al: 0.5% or more and/or Si: 0.4% or more and satisfies the following expression (1).
Cr+10Si+Mn+Al>24.5  (1)

Provided is a stainless steel substrate for a solar cell, the stainless steel substrate including, by mass %, Cr: 9% to 25%, C: 0.03% or less, Mn: 2% or less, P: 0.05% or less, S: 0.01% or less, N: 0.03% or less, Al: 0.005% to 5.0%, Si: 0.05% to 4.0%, and a remainder including Fe and unavoidable impurities, in which an oxide film containing (i) Al.sub.2O.sub.3 in an amount of 50% or more or containing (i) Al.sub.2O.sub.3 and (ii) SiO.sub.2 in a total amount of 50% or more is formed on a surface of stainless steel having a composition which contains Al: 0.5% or more and/or Si: 0.4% or more and satisfies the following expression (1).
Cr+10Si+Mn+Al>24.5  (1)

A process of remanufacturing a component such as an attachment flange used in turbochargers is provided and includes using a steam oxidation process to form an adhesion layer on top of a sealing surface of the component. The adhesion layer is an oxidation layer that a thermal metal spray coating can be applied on top of in order to prevent spalling that can occur at high heat. Once the process is completed, the component can be inspected to ensure that it meets or exceeds the manufacturer's original specifications.

A process of remanufacturing a component such as an attachment flange used in turbochargers is provided and includes using a steam oxidation process to form an adhesion layer on top of a sealing surface of the component. The adhesion layer is an oxidation layer that a thermal metal spray coating can be applied on top of in order to prevent spalling that can occur at high heat. Once the process is completed, the component can be inspected to ensure that it meets or exceeds the manufacturer's original specifications.

Provided is a process for preparing an electrode comprising an iron active material. The process comprises first fabricating an electrode comprising an iron active material, and then treating the surface of the electrode with water to thereby create an oxidized surface. The resulting iron electrode is preconditioned prior to any charge-discharge cycle to have the assessable surface of the iron active material in the same oxidation state as in discharged iron negative electrodes active material.

Provided is a process for preparing an electrode comprising an iron active material. The process comprises first fabricating an electrode comprising an iron active material, and then treating the surface of the electrode with water to thereby create an oxidized surface. The resulting iron electrode is preconditioned prior to any charge-discharge cycle to have the assessable surface of the iron active material in the same oxidation state as in discharged iron negative electrodes active material.

An embodiment of the present invention provides a grain-oriented electrical steel sheet, including a groove including a bottom portion and a side portion positioned on a surface of the electrical steel sheet, a metal oxide layer positioned on the groove, and an insulating layer positioned on the metal oxide layer, wherein the steel sheet includes a normal groove in which thicknesses of the metal oxide layer positioned on the bottom portion and the side portion exceed 0.5 μm, and a defective groove in which thicknesses of the metal oxide layer positioned on the bottom portion and the side portion are 0.5 μm or less, the insulating layer positioned on the normal groove has a thickness of 0.5 μm to 1.5 μm, and the insulating layer positioned on the defective groove has a thickness of 1.5 to 10 μm.

A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: manufacturing a cold-rolled sheet; forming a groove in the cold-rolled sheet; removing an Fe—O oxide formed on a surface of the cold-rolled sheet; primary recrystallization annealing the cold-rolled sheet; and applying an annealing separating agent to the primary recrystallized cold-rolled sheet, and secondary recrystallization annealing it, wherein a close contacting property coefficient calculated by Formula 1 below is 0.016 to 1.13.

close contacting property coefficient (S.sub.ad)=(0.8×R)/H.sub.hill-up  [Formula 1] (In Formula 1, R represents the average roughness (μm) of the surface of the cold-rolled sheet after the removing of the oxide, and H.sub.hill-up represents the average height (μm) of the hill-up present on the surface of the cold-rolled sheet after the removing of the oxide.)

A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention, includes: manufacturing a cold-rolled sheet; forming a groove by irradiating a laser beam on the cold-rolled sheet; and partially removing an oxide layer formed on a surface of the cold-rolled sheet so that a thickness of the oxide layer remains at 1 to 5 nm, wherein the grain-oriented electrical steel sheet has islands of 0.25 or less having sphericity of 0.5 to 0.9 under the oxide layer under the groove.

A spring steel wire includes a main body made of a steel and having a line shape, and an oxidized layer covering an outer peripheral surface of the main body. The steel constituting the main body contains not less than 0.62 mass % and not more than 0.68 mass % C, not less than 1.6 mass % and not more than 2 mass % Si, not less than 0.2 mass % and not more than 0.5 mass % Mn, not less than 1.7 mass % and not more than 2 mass % Cr, and not less than 0.15 mass % and not more than 0.25 mass % V, with the balance being Fe and unavoidable impurities. A value obtained by dividing a sum of a Si content and a Mn content by a Cr content is not less than 0.9 and not more than 1.4. The steel constituting the main body has a tempered martensite structure.