A grain-oriented electrical steel sheet having an insulating film disposed on a surface thereon. The insulating film having a chemical composition comprising Si, P, O, and at least one selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, Mn, and Co. The insulating film has a crystallinity in a range of 20% or more, and a minimum tension provided to the steel sheet by the insulating film at a temperature in a range of 100 C. to 200 C. is 10 MPa or more.

A grain-oriented electrical steel sheet having an insulating film disposed on a surface thereon. The insulating film having a chemical composition comprising Si, P, O, and at least one selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, Mn, and Co. The insulating film has a crystallinity in a range of 20% or more, and a minimum tension provided to the steel sheet by the insulating film at a temperature in a range of 100 C. to 200 C. is 10 MPa or more.

A novel method of blackening surgical needles is disclosed. Surgical needles having outer surfaces are first placed into a first pretreatment bath having a novel composition. The needles are then placed into a second blackening bath having a novel composition for a sufficient period of time to effectively blacken the surfaces of the needles. The novel methods for blackening the surfaces of a stainless steel alloy surgical needle provide a chromium (VI)-free alternative to current needle manufacturing processes. Another unique feature of this novel method is its short processing time. The blackening processes of the present invention can be utilized for in-line treatment processes which can be easily incorporated into high speed needle manufacturing processes, such as strip mounted processes. In addition, the processes of the present invention are readily adaptable to batch processes. Also disclosed are novel systems for blackening surgical needles and novel blackening baths for surgical needles.

A stainless steel sheet for fuel cell separators comprises: a predetermined chemical composition; and Cr-containing fine precipitates at a steel sheet surface, wherein an average equivalent circular diameter of the fine precipitates is 20 nm or more and 500 nm or less, and a number of the fine precipitates existing per 1 m.sup.2 at the steel sheet surface is three or more.

A novel method of blackening surgical needles is disclosed. Surgical needles having outer surfaces are first placed into a first pretreatment bath having a novel composition. The needles are then placed into a second blackening bath having a novel composition for a sufficient period of time to effectively blacken the surfaces of the needles. The novel methods for blackening the surfaces of a stainless steel alloy surgical needle provide a chromium (VI)-free alternative to current needle manufacturing processes. Another unique feature of this novel method is its short processing time. The blackening processes of the present invention can be utilized for in-line treatment processes which can be easily incorporated into high speed needle manufacturing processes, such as strip mounted processes. In addition, the processes of the present invention are readily adaptable to batch processes. Also disclosed are novel systems for blackening surgical needles and novel blackening baths for surgical needles.

This grain-oriented electrical steel sheet includes: a base steel sheet; and an insulating coating formed on a surface of the base steel sheet, in which the insulating coating includes an intermediate layer formed on a base steel sheet side and containing a crystalline metal phosphate, and a tension coating layer formed on a surface side of the insulating coating, the surface of the base steel sheet has an etch pit structure, an average thickness of the intermediate layer is 0.2 to 10.0 ?m, an average thickness of the insulating coating is 2.0 to 10.0 ?m, the tension coating layer contains a metal phosphate and silica, and an amount of the silica in the tension coating layer is 20 to 60 mass %.

Provided is a method of manufacturing a grain-oriented electrical steel sheet having an excellent film adhesion can be obtained. The method of manufacturing a grain-oriented electrical steel sheet includes subjecting a steel slab to hot rolling to obtain a hot-rolled steel sheet, subjecting the hot-rolled steel sheet to cold rolling once to obtain a cold-rolled steel sheet, subjecting the cold-rolled steel sheet to pickling, subjecting the cold-rolled steel sheet to decarburization annealing, applying an annealing separator to a surface of the cold-rolled steel sheet after the decarburization annealing, and subjecting the cold-rolled steel sheet to final annealing, where in the pickling, a solution with an acid concentration of 1.0 mass % to 20 mass % and an Fe ion concentration of 2 mass % to 15 mass % is used, and in the decarburization annealing, a concentration of CO in an atmosphere gas is maintained at 6 vol % or less.

Provided is a method for manufacturing a micropore filter usable as SCE. Stainless steel particles having particle diameters of 3 to 60 ?m are subjected to milling in a bead mill using zirconia beads to prepare powder having a flakiness of 0.03 to 0.4. The zirconia adhered to the surface of the powder is removed by pickling. A load of 10 to 15 kN is applied to 0.5 to 1.0 g of the pickled powder, thereby compacting the powder into a columnar compact body. The compact body is kept and fired in a vacuum atmosphere of 10.sup.?5 to 10.sup.?3 Pa at a temperature of 1000 to 1300? C. for 1 to 3 hours to form a sintered body. The sintered body is pressed into a pipe having an inner diameter of 0.90 to 0.99 times of the outer diameter of the sintered body, and extruded to obtain a micropore filter.

A method for pickling a steel plate having a first steel plate portion and a second steel plate portion which is connected to a tail end of the first steel plate portion and which requires a longer time for pickling than the first steel plate portion when pickled under the same condition includes: a step of pickling the steel plate by immersing the steel plate in an acid solution in at least one pickling tank while conveying the steel plate; a step of circulating the acid solution, through a circulation line connected to any of the at least one pickling tank, between the pickling tank and an oxidizing device disposed in the circulation line; a step of oxidizing Fe.sup.2+ in the acid solution to Fe.sup.3+ by the oxidizing device using a gaseous oxidant; and a feeding start step of, upon switching from pickling of the first steel plate portion to pickling of the second steel plate portion, starting feeding of a liquid oxidant for oxidizing Fe.sup.2+ in the acid solution to Fe.sup.3+ to any of the at least one pickling tank or to the circulation line.

The grain-oriented electrical steel sheet is a grain-oriented electrical steel sheet which does not have an inorganic coating containing forsterite as a main component, including a base steel sheet having a predetermined chemical component, a silicon-containing oxide layer provided on the base steel sheet, an iron-based oxide layer provided on the silicon-containing oxide layer, and a tension-insulation coating provided on the iron-based oxide layer, having a thickness of 1 to 3 m, and containing phosphate and colloidal silica as main components. When elemental analysis is performed from a surface of the tension-insulation coating in a sheet thickness direction by glow discharge optical emission spectrometry, predetermined requirements are satisfied.