shipbuilding steel plate refers to the hot-rolled steel plate produced in accordance with the requirements of the classification society's construction specifications for the manufacture of ship structures. Due to the bad working environment of the ship, the hull is subject to the chemical corrosion and electrochemical corrosion of sea water and the corrosion of marine organisms and microorganisms;
The shape of the ship makes the processing method complex and so on, so the requirements of the shipbuilding steel plate are strict.
First of all, good toughness is the most critical requirement. In addition, high strength, good corrosion resistance, welding performance, processing and forming performance and surface quality are required. In order to ensure the quality and enough toughness of shipbuilding steel plate, the chemical composition of Mn / C is required to be more than 2.5, and the carbon equivalent is also strictly required, which is produced by the steel plant approved by the ship inspection department.
According to the minimum yield point, the strength grades of shipbuilding steel plate are general strength structural steel and high strength structural steel. There are two kinds of shipbuilding steel plate: general thickness steel and high-strength steel. General strength steel is divided into four grades according to its quality: A, B, C and D. high strength steel is divided into two strength grades and three quality grades: ah32, dh32, EH32, AH36, DH36 and EH36.
The general strength structural steel of CCS code standard is divided into four quality grades: A, B, D and E (i.e. CCSA, CCSB, CCSC and CCSD);
The high-strength structural steel specified by CCS has three strength levels and four quality levels. The main classification society's specifications are: marine steel plate CCS in China, ABS in the United States, GL in Germany, BV in France, DNV in Norway, KDK in Japan, LR in the United Kingdom.
