Fusion Power Seeks Super Steels

From BBC News | Technology | World Edition:

Scientists say an understanding of how the Twin Towers collapsed will lead to new steels needed to build fusion reactors. New research shows how steel will fail at high temperatures because of the magnetic properties of the metal. The New York buildings fell when their steel backbones lost strength in the fires that followed the plane impacts. Dr Sergei Dudarev told the British Association Science Festival that improved steels were now being sought. The principal scientist at the United Kingdom Atomic Energy Authority (UKAEA) said one of the first applications for these better performing metals would be in the wall linings of fusion reactors where temperatures would be in a similar range to those experienced in the Twin Towers' fires. 'Not melting' The key advance is the understanding that, at high temperatures, tiny irregularities in a steel's structure can disrupt its internal magnetic fields, making the rigid metal soft. "Steels melt at about 1,150C (2,102F), but lose strength at much lower temperatures," explained Dr Sergei Dudarev, principal scientist at the United Kingdom Atomic Energy Authority (UKAEA). At room temperature, the magnetic fields between iron atoms remain regular, but when heated, these fields are altered allowing the atoms to slide past each other, weakening the steel. "[The steel] becomes very soft. It is not melting but the effect is the same," said Dr Dudarev. He said blacksmiths had exploited this property for hundreds of years - it allows iron to become pliable at temperatures much lower than its melting point.

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