Arctic freeze a breeze for superstrong steel

 作者:和蓓拣     |      日期:2019-03-14 05:07:02
By Paul Marks STEEL is valued for its reliability when making everything from bolts to boats – but not when it gets cold. Most forms of steel abruptly become brittle at temperatures below about -25 °C unless they are mixed with other metals. Now, though, a novel type of steel has been developed that resists fractures at much lower temperatures, while retaining its strength and toughness – without the need for expensive additives. Steel’s fragility at low temperatures first became a major concern during the second world war. After German U-boats torpedoed numerous British ships,