This invention provides a roll-bonded laminate composed of a hard copper layer and a stainless steel layer, which is sufficient both in radiation performance and strength. A roll-bonded laminate 1A is composed of a copper layer 10A and a stainless steel layer 20A, in which thickness of the roll-bonded laminate 1A is 0.02 mm to 0.4 mm, hardness of the copper layer 10A is 70 Hv or higher, and 180° peel strength of the roll-bonded laminate 1A is 6 N/20 mm or more.

A grain oriented electrical steel sheet includes a base steel sheet, an oxide layer, and a tension-insulation coating. When the iron oxide layer is analyzed by a fourier transform infrared spectroscopy, an absorbance A.sub.650 at 650 cm.sup.−1 and an absorbance A.sub.1250 at 1250 cm.sup.−1 satisfy 0.2≤A.sub.650/A.sub.1250≤5.0. Moreover, a magnetic flux density B8 in a rolling direction of the grain oriented electrical steel sheet is 1.90 T or more.

An inhibited mud acid composition, said composition comprising: hydrofluoric acid in solution; an alkanolamine; and a mineral acid selected from a group consisting of: HCl; MEA-HCl and other modified acids, wherein said alkanolamine and hydrofluoric acid are present in a molar ratio of at least 1:1.

This invention provides a roll-bonded laminate composed of a hard copper layer and a stainless steel layer, which is sufficient both in radiation performance and strength. A roll-bonded laminate 1A is composed of a copper layer 10A and a stainless steel layer 20A, in which thickness of the roll-bonded laminate 1A is 0.02 mm to 0.4 mm, hardness of the copper layer 10A is 70 Hv or higher, and 180° peel strength of the roll-bonded laminate 1A is 6 N/20 mm or more.

Provided is an acid-pickling additive for a surface oxide scale of a stainless steel material, a preparation method thereof and an acid-pickling method. The acid-pickling additive consists of 1 to 10 parts by weight of an alcohol amine compound, 0.1 to 5 parts by weight of a metal complex ligand, 0 to 10 parts by weight of a nitrogen-containing organic cyclic compound, 0 to 3 parts by weight of an alcohol compound, 0 to 3 parts by weight of a plant extract, and 1 to 2 parts by weight of water. This acid-pickling additive can solve the problems of high energy consumption, environmental pollution, and high cost in the existing method for removing an oxide scale of a stainless steel.

The present disclosure relates to austenitic stainless steel with excellent electrical conductivity in which metal copper is formed in a non-conductive passivation film formed on the surface of stainless steel, and a method of manufacturing the same.

The austenitic stainless steel with excellent electrical conductivity according to an embodiment of present disclosure includes: a stainless steel base material comprising, in percent (%) by weight of the entire composition, C: 0.1% or less, Si: 0.1 to 1.0% or less, Mn: 0.1 to 2.0% or less, Cr: 15 to 24% or less, Ni: 6 to 12% or less, Cu: 0.5 to 3% or less, the remainder of iron (Fe) and other inevitable impurities; and a passivation film formed on the stainless steel base material, and the passivation film has a thickness of more than 0 and less than or equal to 5 nm, the Cu weight % content in the thickness region between 2 to 3 nm from the surface of the passivation film is 1.5 or more compared to the Cu weight % content of the stainless steel base material.

Stainless steel with improved hydrophilicity and contact resistance for a Polymer Electrolyte Membrane Fuel Cell (PEMFC) separator, and a method of manufacturing the stainless steel Stainless steel are disclosed. Stainless steel for a Polymer Electrolyte Membrane Fuel Cell (PEMFC) separator according to an embodiment of the present disclosure may include: by weight percent, 0 to 0.02% of C (excluding 0), 0 to 0.02% of N (excluding 0), 0 to 0.25% of Si (excluding 0), 0 to 0.2% of Mn (excluding 0), 0 to 0.04% of P (excluding 0), 0 to 0.02% of S (excluding 0), 20 to 34% of Cr, 0 to 0.6% of V (excluding 0), 0 to 0.5% of Ti (excluding 0), 0 to 0.5% of Nb (excluding 0), and the remainder comprising iron (Fe) and other unavoidable impurities, wherein a plurality of patterns may be formed on a surface of the stainless steel in a direction that is inclined with respect to a rolling direction, and the plurality of patterns are arranged repeatedly in the rolling direction.

Ferritic stainless steel is characterized by including, by mass %: Cr: 12.0% to 16.0%; C: 0.020% or less; Si: 2.50% or less; Mn: 1.00% or less; P: 0.050% or less; S: 0.0030% or less; Al: 2.50% or less; N: 0.030% or less; Nb: 0.001% to 1.00%; one or more of B: 0.0200% or less, Sn: 0.20% or less, Ga: 0.0200% or less, Mg: 0.0200% or less, and Ca: 0.0100% or less; and a balance consisting of Fe and impurities, in which Expression (1) is satisfied.

10(B+Ga)+Sn+Mg+Ca >0.020 (1)

A pickling facility includes: a pickling tank for storing an acid solution; a conveyance part for continuously conveying a steel plate immersed in the acid solution; a measurement part for measuring at least one parameter which has a correlation with a heat transfer coefficient between the acid solution and a reference surface disposed in the acid solution so as to face the steel plate; and a conveyance speed decision part configured to decide a conveyance speed of the steel plate conveyed by the conveyance part, on the basis of a measurement result of the at least one parameter.

An inhibited mud acid composition, said composition comprising: hydrofluoric acid in solution; an alkanolamine; and a mineral acid selected from a group consisting of: HCl; MEA-HCl and other modified acids, wherein said alkanolamine and hydrofluoric acid are present in a molar ratio of at least 1:1.