Abstract: A method for improving the resistance to surface roughening of tungsten-containing metallic articles such as cutting tools and hot mill rolls made of a cemented carbide or high-speed steel and extending the lifetime thereof. The method comprises treating a metallic article with an aqueous alkaline solution containing calcium ions and optionally tungstate ions having a pH greater than 8 so as to form a coating of calcium tungstate on the surface of the metallic article. In hot rolling with tungsten-containing rolls, the aqueous solution can be used as at least part of a cooling water to cool the rolls, thereby extending the period before roll replacement becomes necessary due to surface roughening and decreasing the frequency of roll dressing required during hot rolling.

Abstract: A process for manufacturing a precast composite structure of a matrix of cured carbon fiber reinforced concrete and at least one ferrous metallic member at least partly buried in said matrix, by forming an insulating layer of an electric resistance of at least about 100 ohms at least on that surface of the ferrous metallic member, which will otherwise be brought in contact with a concrete mix, placing the metallic member in position in a mold, pouring into the mold a concrete mix containing 0.2 to 10% by volume of carbon fiber so that said metallic member may be at least partly buried in said concrete mix, partly curing the structure until it becomes self-supporting, de-molding the partly cured structure, and fully curing the structure in an autoclave at a temperature between 100.degree. C. and 215.degree. C.