What is the production process of shipbuilding steel plate

Grade A and B shipbuilding steel plates with general strength can meet their technical and mechanical performance requirements through ordinary rolling, so the production process is relatively simple; while the production of D, E and high-strength grade shipbuilding steel plates requires relatively complete equipment.

At the same time, there is a high requirement for the purity of the internal steel quality of the supplied billet, especially the content of S, P, N, O, H, etc. in the steel must be strictly controlled.

In order to reduce costs, it is the best policy to produce shipbuilding steel plates by hot rolling or controlled rolling instead of normalizing. For high-strength ship plates with a thickness less than 35mm, two-stage controlled rolling has been adopted for production; high-strength ship plates with a thickness greater than 35mm are mostly produced by hot rolling and normalizing.

In order to ensure the performance of high-strength shipbuilding steel plates, micro-alloying technology is adopted. By adding Nb, V, Ti and other alloying elements to the steel, combined with the controlled rolling process, the grains are refined and the strength and toughness are improved. Due to the limitation of billet shape and billet weight, many manufacturers cannot produce extra-thick ship plates. The thick plate plants of Puyang Iron and Steel Co., Ltd. and Wuyang Iron and Steel Co., Ltd. can use large slabs or large ingots to roll ship plates with a thickness greater than 50mm.

D and E grade shipbuilding steel plates require good low-temperature toughness and good welding performance, which must first be guaranteed in the steel smelting process, and secondly, effective controlled rolling and controlled cooling processes must be implemented. In recent years, major domestic iron and steel enterprises have fully realized the importance of improving the internal quality of steel.

Relying on the progress of smelting technology, improvements have been made in the links of hot metal desulfurization and slag removal, steelmaking hydrogen blowing, and vacuum refining outside the furnace, which have significantly reduced the harmfulness of steel. Content of elements and impurities