Steel that has been hardened by rapid quenching is brittle and not suitable for most uses.
快速淬火硬化的钢是硬而易碎的，不适合大多数场合使用。
2
The rapid rebound in steel demand.
钢铁需求迅速回升。
3
To enjoy the benefits of concrete - preventing rapid warming and overheating of the interior - the grooves in the steel sheets are partly filled with concrete.