Introduction to Steel for Hull Structure

 　　The steel used for general strength hull structures is divided into four grades: A, B, D, and E. The yield strength (not less than 235N/mm ^ 2) and tensile strength (400-520N/mm ^ 2) of these four grades of steel are the same, but the impact energy at different temperatures is different;

　　High strength hull structural steel is classified into strength grades based on its minimum yield strength, and each strength grade is divided into A, D, E, and F4 grades according to its different impact toughness.

　　The yield strength of A32, D32, E32, and F32 shall not be less than 315N/mm ^ 2, and the tensile strength shall be 440-570N/mm ^ 2. A, D, E, and F respectively represent the impact toughness that they can achieve at 0 °, -20 °, -40 °, and -60 °, respectively;

　　The yield strength of A36, D36, E36, and F36 shall not be less than 355N/mm ^ 2, and the tensile strength shall be 490-620N/mm ^ 2. A, D, E, and F respectively represent the impact toughness that they can achieve at 0 °, -20 °, -40 °, and -60 °, respectively;

　　The yield strength of A40, D40, E40, and F40 shall not be less than 390N/mm ^ 2, and the tensile strength shall be 510~660N/mm ^ 2. A, D, E, and F respectively represent the impact toughness that they can achieve at 0 °, -20 °, -40 °, and -60 °, respectively.

　　also,

　　High strength quenched and tempered steel for welded structures: A420, D420, E420, F420; A460、D460、E460、F460； A500、D500、E500、F500； A550、D550、E550、F550； A620、D620、E620、F620； A690、D690、E690、F690；

　　Steel for boilers and pressure vessels: 360A, 360B; 410A、410B； 460A、460B； 490A、490B； 1Cr0.5Mo、2.25Cr1Mo

　　Steel for mechanical structure: Generally, the above steel can be selected;

　　Low temperature toughness steel: 0.5NiA, 0.5NiB, 1.5Ni, 3.5Ni, 5Ni, 9Ni;

　　Austenitic stainless steel: 00Cr18Ni10, 00Cr18Ni10N, 00Cr17Ni14Mo2, 00Cr17Ni13Mo2N, 00Cr19Ni13Mo3, 00Cr19Ni13Mo3N, 0Cr18Ni11Nb;

　　Duplex stainless steel: 00Cr22Ni5Mo3N, 00Cr25Ni6Mo3Cu, 00Cr25Ni7Mo4N3.

　　Composite steel plate: suitable for containers and cargo tanks of chemical product transport ships;

　　Z-direction steel: refers to steel that has undergone special treatments (such as calcium treatment, vacuum degassing, argon stirring, etc.) and appropriate heat treatment on the basis of a certain level of structural steel (referred to as parent steel).