Abstract: A Si-containing high-strength cold rolled steel sheet has a chemical composition comprising C: 0.0˜20.3 mass %, Si: 0.8˜2.0 mass %, Mn: 1.0˜5.0 mass % and the remainder being Fe and inevitable impurities with a ratio of Si content to Mn content (Si/Mn) exceeding 0.4, and has a tensile strength TS of not less than 780 MPa, wherein a metallic structure of the steel sheet surface contains polygonal ferrite and/or bainitic ferrite having a Si concentration of not more than 3.0 mass % and a grain size of not more than 10 ?m and does not have a Si-containing oxide layer on the steel sheet surface.

Abstract: A cooling device and a cooling method for a hot strip allow uniform and stable cooling of the strip at a high cooling rate when supplying the coolant to the upper surface of the hot strip. The cooling device includes an upper header unit 21 for supplying a rod-like flow to the upper surface of the strip 10. The upper header unit 21 is formed of the first upper header group including plural first upper headers 21a arranged in a conveying direction and a second upper header group including plural second upper headers 21b arranged in the conveying direction. The cooling device is provided with an ON-OFF mechanism 30 to allow each of the upper headers 21a and 21b of the first and the second upper header groups to independently execute the ON-OFF control (start/end injection control) of an injection (feeding) of the rod-like flow.

Abstract: A method of cooling both surfaces of steel plate, which stably secures precision of cooling control from a start of cooling to an end so as to uniformly cool the top and bottom surfaces of the steel plate and thereby stably secures the steel plate quality and cools the steel plate down to a target temperature with a good precision. The method comprises dividing a steel plate cooling region into at least a spray impact part region and a spray non-impact part region, predicting a heat transfer coefficient for each divided region in advance, computing a predicted temperature history of the steel plate based on this predicted value, and setting and controlling amounts of sprayed coolant on the spray impact part regions by top and bottom surface nozzles.

Abstract: To provide a method for simply and easily causing only IGSCC to initiate and grow in a specimen, which can retain corrosion resistance through passivation, under atmospheric pressure in a short time, an aqueous solution of potassium tetrathionate is brought into contact with the specimen capable of retaining corrosion resistance through passivation. The potassium tetrathionate concentration, temperature and pH value of the aqueous solution are from 0.3 to 6 wt. %, from 5 to 60° C., and from 3 to 6, respectively.

Abstract: A thermodynamic metal treating apparatus and process describes utilizing a quenchant mixture of liquid and gas in a cell. Heated metal is passed over the heated quenchant mixture which contains a liquid and a gas such as air bubbled through the liquid at a desired rate. The process is particularly suited for improving the breaking, tensile strength and ductility of steel wire as is used in belted vehicle tires. A series of quenching cells allow for fast, uniform treatment of the metal wire.

Abstract: A ferrous-alloy aircraft structural component such as a fastener is prepared by providing a ferrous-alloy component precursor that is not in its final heat-treated state, and coating with an aluminum-containing, curable organic coating material having a non-volatile portion that is predominantly organic and is curable at about the ferrous-alloy component's tempering temperature. The coated, ferrous-alloy is then tempered to concurrently impart predetermined metallurgical properties to the finished, ferrous-alloy material, and cure the organic, aluminum-containing coating.

Abstract: The invention provides hot-rolled steel strips which, after having been acid-pickled, can be directly used. The strips have no Cr-decreasing layer and no shot blasted marks on their surface and have good corrosion resistance. The invention also provides a technique of efficiently producing the hot-rolled steel strips. A steel slab having a Cr content of from 6.0 to 25.0 wt. % is hot-rolled, then coiled at a temperature not higher than 700° C., then optionally quenched in water immediately after the coiling, then annealing in a reducing atmosphere, and thereafter acid-pickled in a solution of nitric acid/hydrochloric acid.

Abstract: The subject invention provides a method for manufacturing a spring band clip, wherein an alloyed steel is shaped, annealed, levelled into a narrow band, then shaped by stamping and bending into a non-machined clip, and the surface of the non-machined clip is smoothed and treated to produce resistance to corrosion; wherein the steel comprises iron as the main component and one or more of the following components by weight: 0.32 to 0.55% C; up to 2.0% Si; up to 2.0% Mn; up to 0.04% P; up to 0.04% S; 17.5 to 20% Cr; up to 1% Ni; 0.5 to 2.5% Mo; up to 0.5% V; up to 0.1% Al; up to 0.1% Co; up to 0.4% Cu; up to 0.4% Pb; up to 0.1% Se; up to 0.1% Te; up to 0.005% Ti; up to 0.1% W; up to 0.05% Zr; up to 0.01% O.sub.2 ; up to 0.01% N; up to 0.1% Bi; up to 0.001% B; up to 0.05% Nb; wherein the non-machined clip is austenitized prior to being smoothed and is converted into martensite by heat treatment in a salt-, oil-, or water bath, or by quenching at about the austenitizing temperature.

Abstract: A method of quenching a metal object having steps of: (a) providing a liquid coolant having a temperature from about 100.degree. F. to about 180.degree. F. and containing about 0.01 to about 0.1 standard cubic feet of carbon dioxide gas per gallon of water dissolved therein; and (b) spraying the liquid coolant on the metal object to quench the metal object.

Abstract: Method and apparatus for densifying an article wherein the article is disposed in a first molten salt pressure transmission medium in a container. The first medium is heated to a first elevated densifying temperature. The container is disposed in a second molten salt pressure transmission medium at a second temperature lower than the first temperature. The first medium and the second medium are communicated so that pressure applied to the second medium is transmitted to the first medium. Pressure is applied to the lower temperature second medium sufficient to densify the article disposed in the first higher temperature medium. Following densification of the article, the container is removed from the second medium. The method and apparatus are especially useful for closing internal porosity of metallic and intermetallic castings.

Abstract: A water box is used to cool hot rolled products in a rolling mill. The water box includes a base structure supporting a removable manifold, and a plurality of nozzles removably mounted on and in fluid communication with the manifold. The nozzles are lined with inserts which may be replaced when worn. The manifold is reversible end to end, as are the nozzles, thus enabling the water box to be used on either of two parallel rolling lines.

Abstract: In composition of a Fe-Ni alloy used for television shadow masks and containing in, Co, Mn, Si and Cr as the major components, additional inclusion of Be assures high deformation resistance and easy pore formation via etching without impairing its inherent low thermal expansion. Introduction of annealing at 800.degree. to 1200.degree. C. temperature into production process sufficiently lowers proof stress of the product without causing any noticeable crystal coarseness. Increased mechanical strength enables production of a thin shadow mask material well suited for pore formation via etching, thereby assuring high grade screen display.