Abstract: A device for treating fluid, in particular a supported catalyst for motor vehicle exhaust gas purification. The device comprises a plurality of short helical lengths of smooth surfaced wire of aluminium containing iron based alloy wound to avoid self contact, coated with ceramic material and catalytically active material, and assembled together in a container having a gas inlet and a gas outlet.

Abstract: Certain alloys of iron, chromium, aluminium and yttrium are known e.g. from U.S. Pat. No. 3,027,252 and from U.K. Pat. No. 1,045,993 and are stated to be high temperature, oxidation resistant alloys.The invention relates to alloys of iron, chromium, aluminium and yttrium containing additionally certain proportions of silicon. Thus, the alloys of the invention comprise from 15 to 25% Cr, 4 to 5.5% Al, 0.01 to 3% Y, 0.3 to 5% Si and the balance Fe, where all proportions are by weight. The corrosion resistance of the alloys increases as the percentage of Si increases to reach a peak at about 1% Si. The preferred range of Si is 0.5 to 2%. All proportions are by weight.