According to its minimum yield point, structural steel for hull is divided into general strength structural steel and high strength structural steel. Ship plate refers to the hot-rolled steel plate produced according to the classification society construction specification for the manufacture of hull structure.
The marine ship building steel sheets is mainly used for producing boats body and decks. This kind steel is good at preventing hull from being corroded by chemical corrosion, electrochemical corrosion and sea life and microorganisams.
Due to the harsh working environment of the ship, the hull shell is subject to chemical corrosion of seawater, electrochemical corrosion and corrosion of marine organisms and microorganisms; the hull is subjected to large wind and wave impacts and alternating loads; the shape of the ship is complicated by processing methods, etc. Steel for hull structure is strictly required. First of all, good toughness is the most critical requirement. In addition, high strength, good corrosion resistance, weldability, forming properties and surface quality are required.
For marine steel plate, China Classification Society standard is three strength grades and four quality grades.
The yield strength of A32, D32, E32 and F32 is not less than 315N/mm^2, and the tensile strength is 440~570N/mm^2. A, D, E and F respectively indicate that they can be at 0° and -20° respectively. Impact toughness that can be achieved at -40°, -60°