Steel for warships refers to the steel used for hull structures of military surface ships (such as destroyers, cruisers), underwater submarines (such as conventionally powered submarines, nuclear powered submarines) and minesweepers. The steel used for warships is the most important, important and critical structural material in the construction of modern ships, and its performance is directly related to the improvement of the tactical performance of ships.
Modern warships are required to reduce their own weight while improving their payload and defense capabilities, and to maintain structural integrity even in harsh conditions. Therefore, higher requirements are placed on the performance of ship steel plates. Steel plates must have high strength and toughness, good workability and excellent corrosion resistance in high-salt and high-humidity environments.
In production, steel for warships has the characteristics of small batches, many specifications and high standards.
The key property of warship steel is yield strength. In order to meet the needs of large surface warships and deep-dive submarines, the yield strength requirements of warship steel are gradually increasing.
Take the United States as an example. After World War II, the US Navy was the only country that continued to own aircraft carriers. At present, the number of aircraft carriers in the United States accounts for half of the world's total, and the tonnage of a single ship is as high as 100,000 tons. A large number of 690MPa high-strength plates are used on its aircraft carriers. As deck steel, HSLA115 steel with a yield strength of 785MPa is used on the "Ford" class aircraft carrier.
In order to meet the large diving depth requirements of large submarines, the United States, Japan, Russia and other countries generally use steel plates with a yield strength of 900-1080MPa as the steel for submarine pressure hulls. The United States has self-developed HY and HSLA series of high-strength steels. The highest strength is above 1000MPa. Russia has AB7A steel with a yield strength of 1175MPa. In the 1990s, Japan developed NS110 grade steel with a yield strength of 1000MPa, which is used in "pro-tide" submarines, with a maximum diving depth of 500m.
