Marine steel plate refers to the hot-rolled steel plate produced in accordance with the requirements of the construction code of classification society for manufacturing hull structures.
Due to the harsh working environment of ships, the hull is corroded by chemical corrosion, electrochemical corrosion and marine organisms and microorganisms. The hull bears large wind and wave impact and alternating load; The shape of the ship makes its processing method complicated, so the requirements for steel for hull structure are strict. First of all, good toughness is the most critical requirement. In addition, it also requires high strength, good corrosion resistance, weldability, processability and surface quality. In order to ensure the quality and sufficient toughness, the Mn/C of chemical composition is required to be above 2.5, and the carbon equivalent is also strictly required, and it is produced by a steel mill recognized by the ship inspection department.
According to the minimum yield point, structural steel for hull can be divided into general strength structural steel and high strength structural steel. Structural steel for hull can be divided into general strength steel and high strength steel, and general strength steel can be divided into four grades according to quality: A, B, D and E; High strength steel is divided into two strength grades and three quality grades; AH32、DH32、EH32、AH36、DH36、EH36。