'Fibrous' steel won't break in a cold snap

cold formed steel Whether used to make bolts, bikes or buses, steel becomes brittleand more likely to fracture at frigid temperatures unless mixedinto expensive alloys. But a novel type of steel can match theirperformance without costly additives. Developed by researchers in Japan, the material could make steelstructures in Arctic areas, like ships or oil rigs, cheaper toconstruct. Yuuji Kimura and colleagues, at the National Institute for Materials Science in Tsukuba, say their new steel's strength comes from its unusualcrystal structure. Steel, an alloy of iron and carbon, is usually formed fromcrystalline grains that have a rounded shape. The new steel hasmuch longer, cylindrical grains that the researchers describe asbeing like fibres. Cold snap Below a certain temperature, all steel switches from beingdeformable to being brittle, as increasing cold weakens theconnections between crystal grains. That effect led to 12 of the US " Liberty ships " made to replace cargo vessels lost in the second world war tobreak in half in cold waters. Cheap, non-alloyed steel typically becomes brittle at about -30 2008-06-11 13:58:21