A process for coating a part by chemical vapor diffusion is provided and includes placing a powder mixture in a chamber, immersing the part partially in the powder mixture, and applying a heat treatment to the part. The powder mixture includes a first component and a second component forming a gaseous compound during the heat treatment so as to allow deposition of the second component on the part. The part includes a metal refractory allow and the second component forms a solid diffusion alloy by solid diffusion with a metal species of the refractory metal alloy to generate a coating. The solid diffusion allow generates a passivating oxide layer when subjected to oxidizing conditions.

An aluminum-based plated steel sheet according to an aspect of the present invention includes: a base material; an aluminum-based plating layer located above the base material; and an intermetallic compound layer that is located between the base material and the aluminum-based plating layer and contains an intermetallic compound of Al and Fe, in which the base material has a chemical component within a predetermined range, the aluminum-based plating layer contains, on average, 80 mass % or more and 97 mass % or less of Al, 3 mass % or more and 15 mass % or less of Si, 0 mass % or more and 5 mass % or less of Zn, 0 mass % or more and 5 mass % or less of Fe, 0 mass % or more and 3 mass % or less in total of one or more selected from the group consisting of Mg and Ca, and impurities so that a total amount thereof is 100 mass %, an average value of a thickness of the intermetallic compound layer is 2 μm or more and 10 μm or less, a maximum value of the thickness of the intermetallic compound layer is 10 μm or more and 25 μm or less, and a standard deviation of the thickness of the intermetallic compound layer is 2 μm or more and 10 μm or less.

Fe-Al-based plated hot-stamped member exhibiting excellent formed part corrosion resistance and post-coating corrosion resistance and manufacturing method. The hot-stamping member includes Fe-Al-based plated layer on one or both surfaces of a base material, the base material has a predetermined steel component, Fe-Al-based plated layer has a thickness of 10 μm or more and 60 μm or less, formed by A, B, C and D layers sequentially from a surface toward the base material, and each of the four layers is a Fe-Al-based intermetallic compound containing Al, Fe, Si, Mn and Cr for predetermined contents with the balance made up of impurities, the D layer further contains Kirkendall voids each of which cross-sectional area is 3 μm.sup.2-30 μm.sup.2 for 10 pieces/6000 μm.sup.2 or more and 40 pieces/6000 μm.sup.2 or less.

Provided is a highly corrosion-resistant plated steel sheet having plating adhesion and resistance to liquid metal embrittlement. A highly corrosion-resistant plated steel sheet comprises a base steel sheet and a plated layer, which sequentially comprises an Fe—Al alloy layer and an MgZn.sub.2 layer from an interface with the base steel sheet.

Provided are a Sn—Bi—In-based low melting-point joining member used in a Pb-free electroconductive joining method in mounting a semiconductor component, and is usable for low-temperature joining, and a manufacturing method therefor.

A Sn—Bi—In-based low melting-point joining member, including a Sn—Bi—In alloy that has a composition within a range represented by a quadrangle in a Sn—Bi—In ternary phase diagram, a first quadrangle having four vertices including: Point 1 (1, 69, 30), Point 2 (26, 52, 22), Point 3 (40, 10, 50), and Point 4 (1, 25, 74), where Point (x, y, z) is defined as a point of x mass % Sn, y mass % Bi and z mass % In, and that also has a melting point of 60 to 110° C. As well as a method for producing a Sn—Bi—In-based low melting-point joining member, including a plating step of forming a plated laminate on an object to be plated, the plated laminate including a laminated plating layer obtained by performing Sn plating, Bi plating, and In plating respectively such that the laminated plating layer has a composition within the range represented by the first quadrangle.

A coated steel member includes: a steel sheet substrate containing, as a chemical composition, by mass %, C: 0.25% to 0.65%, Si: 0.10% to 1.00%, Mn: 0.30% 1.00%, P: 0.050% or less, S: 0.0100% or less, N: 0.010% or less, Ti: 0.010% to 0.100%, B: 0.0005% to 0.0100%, Nb: 0.02% to 0.10%, Mo: 0.10% to 1.00%, Cu: 0.15% to 1.00%, and Ni: 0.05% to 0.25%; and a coating formed on a surface of the steel sheet substrate and containing Al and Fe. The maximum Cu content in a range from the surface to a depth of 5.0 μm is 150% or more of the Cu content of the steel sheet substrate.

A press hardening method including the following steps: A. the provision of a steel sheet for heat treatment being optionally coated with a zinc- or aluminum-based pre-coating, B. the flexible rolling of the steel sheet in the rolling direction so as to obtain a steel sheet having a variable thickness, C. the cutting of the rolled steel sheet to obtain a tailored rolled blank, D. the deposition of a hydrogen barrier pre-coating over a thickness from 10 to 550 nm, E. the heat treatment of the tailored rolled blank to obtain a fully austenitic microstructure in the steel, F. the transfer of the tailored rolled blank into a press tool, G. the hot-forming of the tailored rolled blank to obtain a part having a variable thickness,H. the cooling of the part having a variable thickness obtained at step G).

A press hardening method including: A. provision of a steel sheet for heat treatment, being optionally precoated with a zinc- or aluminum-based pre-coating, B. deposition of a hydrogen barrier pre-coating comprising chromium and not comprising nickel over a thickness from 10 to 550 nm, C. cutting of the precoated steel sheet to obtain a blank, D. heat treatment of the blank at a furnace temperature from 800 to 970° C., during a dwell time from 1 to 12 minutes, in an atmosphere having an oxidizing power equal or higher than that of an atmosphere consisting of 1% by volume of oxygen and equal or smaller than that of an atmosphere consisting of 50% by volume of oxygen, such atmosphere having a dew point between −30 and +30° C., E. transfer of the blank into a press tool, F. hot-forming at a temperature from 600 to 830° C. to obtain a part, G. cooling of the part obtained at step E).

According to one embodiment, a wet-area device includes a main part, a first layer, and a second layer. The first layer is provided on an outer surface of the main part. The second layer is provided on an outer surface of the first layer. A hardness of the second layer is greater than a hardness of the first layer. The first layer includes a first unevenness at a side of the outer surface of the first layer. The first unevenness includes a plurality of recesses and a plurality of protrusions. The second layer includes a second unevenness at a side of an outer surface of the second layer. The second unevenness includes a plurality of recesses and a plurality of protrusions. The second unevenness is arranged along the first unevenness. An average height of the first unevenness is less than an average length of the first unevenness.

A coated steel material including: a base steel, and a coating layer containing a Zn—Al—Mg alloy layer disposed on a surface of the base steel, wherein the coating layer has a predetermined chemical composition, and, in a backscattered electron image of the Zn—Al—Mg alloy layer that is obtained at a time of observing the surface of the Zn—Al—Mg alloy layer after polishing to ½ of the layer thickness, under a scanning electron microscope at a magnification of 100×, Al crystals are present, and the average value of the cumulative circumferential length of the Al crystals is 88 to 195 mm/mm.sup.2.