Abstract: The present invention provides: refractory composite materials protected against oxidation at high temperature; said materials are of the type made by a solid process and include, in characteristic manner, over their entire outside surface, a complex layer containing at least one silicate corresponding to a densification additive used to make them, silica, and a vitreous boron-containing silicate phase; precursors or intermediates for preparing said materials; said precursors including, in characteristic manner, over their entire outside surface, at least one layer of a precursor for borosilicate glass or a layer of borosilicate glass; and a method of preparing said materials (by preparing said precursors) and a method of preparing said precursors.

Abstract: Installation for continuous casting between two rolls (1,2) having parallel axes and defining therebetween and with two fixed lateral walls (3) a casting space for a liquid metal, each lateral wall comprising at least one lateral part (6) placed against the planar end face of an adjacent one of the rolls and constituted by a portion of a disc having an outside diameter equal to that of the adjacent roll, and a part (12) which is central relative to and confronts the casting space and is composed of an insulating refractory material. The disc portion is made from a material having properties of thermal conductivity and mechanical resistance superior to those of the refractory material and is a frustoconical disc portion whose face having the larger radius of curvature is placed against the adjacent roll and the disc portion defines a frustoconical surface which is in contact with the insulating material of the central part.

Abstract: The casting installation is of the type in which the ingot mould is essentially constituted by two rolls (1, 1') which are energetically cooled, substantially horizontal and parallel and rotate in opposite directions, and two lateral closing plates (5), termed "side dams", each maintained in contact with an end of each roll. According to the invention, the rolls (1, 1') have end portions of frustoconical shape and the contact between the rolls and the side dams occurs between the lateral surfaces (4a) of these frustoconical end portions and surfaces (7) of the peripheral parts (9) of the side dams which match their shape. Preferably, the parts (9) of the side dams in contact with the rolls are of ceramic.