A novel briquetting roll having excellent performance such as providing both abrasion resistance and spalling resistance, which can also be manufactured at low cost and in a short period of time, and a method for manufacturing the same, are provided wherein the briquetting roll 1 integrally has an inner layer material 4 and an outer layer material 5, which comprise mutually different materials and are in contact with each other at the respective exterior and interior thereof, and has pockets 6 formed at the outer circumference of the outer layer material 5. A chromium-molybdenum forged steel material is used for the inner layer material 4 and a high-carbon high-speed steel material is used for the outer layer material 5. The outer layer material 5 may be formed on the outside of the inner layer material 4 by a continuous pouring process.

A welded steel part with a very high mechanical strength is provided. The welded steel part is obtained by heating followed by hot forming, then cooling of at least one welded blank obtained by butt welding of at least one first and one second sheet. The at least one first and second sheets including, at least in part, a steel substrate and a pre-coating which includes an intermetallic alloy layer in contact with the steel substrate, topped by a metal alloy layer of aluminum or aluminum-based alloy. A method for the fabrication of a welded steel part and the fabrication of structural or safety parts for automotive vehicles are also provided.

A sliding member includes a substrate containing Fe as a main component and an alloy layer overlaid on the substrate and composed of a Cu-base alloy containing 6 to 12% by mass of Ni and 3 to 9% by mass of Sn. The alloy layer has a body layer and an intermediate layer. The body layer is formed of the Cu-base alloy, while the intermediate layer is composed of an alloy containing Ni, Sn, and Cu which are derived from the Cu-base alloy and Fe derived from the substrate. Taking side close to the substrate as a lower region and the other side as an upper region, a ratio of the total area of hard phases to the observation section of the upper region is 1.2 to 3.0, where the ratio of the total area of the hard phases to the observation section of the lower region is set at 1.

This invention discloses a metal coating method whereby an abrasion resistant and wear resistant coating is first applied to the metal object, the coated metal object is then fused onto the metal object, followed by cooling in a press quench machine, and the resulting coated metal object is more abrasion resistant and wear resistant while retaining the metal object's original shape.

A method of manufacturing a hot-pressed member including heating a coated steel sheet to 850 C. to 950 C., the coated steel sheet including a substrate steel sheet and a coating layer formed on the substrate steel sheet and containing 10% to 25% by mass of Ni and the balance being Zn and incidental impurities, in which the coating weight of the coating layer is 10 to 90 g/m.sup.2 per a side; and starting hot press forming when the temperature of the coated steel sheet which has been heated is 650 C. to 800 C.

The method is for manufacturing a clad material (30), which includes: clad rolling for rolling and bonding a first metal plate (131) made of stainless steel, a second metal plate (132) made of Cu or a Cu alloy, and a third metal plate (133) made of stainless steel in a state in which the first metal plate, the second metal plate, and the third metal plate are stacked in this order. The clad rolling is performed with a pressure-bonding load of 4.4?10.sup.3 N/mm or more. The second layer is made of Cu or a Cu alloy. The third layer is made of stainless steel. The clad material has an overall thickness of 1 mm or less.

A clad steel plate having tensile strength (TS) of 780 MPa or more, excellent bendability, collision resistance, and LME resistance. The clad steel plate having a base metal and a cladding metal on front and back surfaces of the base metal, and the chemical composition and microstructure of the base metal and the cladding metal being appropriately controlled so that the average Vickers hardness (HVL) of the cladding metal is 260 or less, the average Vickers hardness (HVL) of the cladding metal divided by the average Vickers hardness (HVB) of the base metal is 0.80 or less, the boundary roughness between the base metal and the cladding metal is 50 ?m or less at the maximum height Ry, and the number of voids at the boundary between the base metal and the cladding metal is controlled to 20 or fewer per 10 mm length of the boundary.

Provided is a clad welded pipe or tube that has improved pipe or tube mechanical properties by reducing the width of a weld without its function as a clad pipe or tube being impaired. A clad welded pipe or tube comprises: a first layer made of base metal; and a second layer placed on one surface of the first layer, and made of first cladding metal that is a material different from the base metal, wherein a pipe or tube circumferential length L1 of weld metal at a pipe or tube inner surface and a pipe or tube circumferential length L2 of the weld metal at a pipe or tube outer surface in a weld are each 0.0010 mm or more and 1.0 mm or less, and the base metal is not exposed at a first cladding metal-side surface of the clad welded pipe or tube in the weld.

A process for producing a three-dimensionally shaped steel component from a steel sheet with a metallic coating may involve hot forming the steel sheet into the steel component. The metallic coating may involve an FeAl-based alloy. To protect the steel sheet or the steel component against scale formation, the FeAl-based alloy may be applied directly to the steel sheet by galvanic coating and/or physical vapor deposition. The coating produced in this way may contain 30-60% by weight Fe, a balance of Al, and, in some cases, 0.1-10% by weight Mg, 0.1-5% by weight Ti, 0.1-10% by weight Si, 0.1-10% by weight Li, and/or 0.1-10% by weight Ca. Before heating the coated steel sheet as part of the hot forming process, the coated steel sheet may have an FeAl phase is stable to above 900 C.

A method is provided for producing a hot-pressed member including heating a Ni-based coated steel sheet, which includes, on a surface thereof, a ZnNi alloy coating layer containing 13% by mass or more of Ni, in a temperature region of an Ac3 transformation point to 1200 C.; and then hot-pressing the steel sheet.