oil hardened steel

例句：

1. 1. The construction of the bridge required the use of oil hardened steel for its structural integrity.
   建造这座桥需要使用油淬火钢来保证结构的完整性。
2. 2.The engineers used oil hardened steel to reinforce the foundation of the building.
   工程师们使用了油淬火钢来加固建筑物的基础。
3. 3.The oil hardened steel was tested for strength and durability before being used in the construction.
   在施工前，这种油淬火钢进行了强度和耐久性的测试。