aluminum steel triclad transition joint

May 15, 2023

When the aluminum alloy superstructure is connected to the steel hull through aluminum steel tricald transition joint, the high temperature generated by welding will promote the growth of intermetallic compound at the aluminum steel interface. After several welding thermal cycles, a thicker intermediate layer of compound will be formed, which seriously reduces the bonding strength of the composite interface and is prone to composite interface cracking, thus endangering the performance and safety of the ship, And this kind of hidden danger will always exist in the process of ship use, so the maximum temperature of aluminum steel composite interface in the welding process should not exceed 300 ℃. At present, aluminum steel triclad transition joint is generally arranged parallel to the deck. In the process of ship sailing, the hull is subject to bending deformation due to the impact of waves, which produces tensile effect on the transition joint and makes it easy to crack; If the welding process is not strictly controlled, the transition joint of local structure will crack during welding.



Marine aluminum steel triclad transition joint three-layer metal materials are: aluminum alloy 5083; 1050 industrial pure aluminum (intermediate layer); Class D common hull plate CCSD. The main alloy element of 5083 aluminum alloy is magnesium, which has good weldability, the tensile strength can reach 350 MPa [9], and the tensile strength of welded joint can reach 270 MPa; According to the rules and standards of China Classification Society, the general marine structural steel can be divided into four quality grades A, B, D and e. the yield strength of CCSD marine steel is not less than 235 MPa and the tensile strength is 400-520 MPa; CO2 gas shielded welding has become the main welding method for marine steel due to its convenient operation, high welding efficiency and wide range of application. The intermediate layer is industrial pure aluminum, and its tensile strength is 75 ~ 130 MPa. At present, aluminum steel transition joint is widely used in ships, which is connected with steel structure through low steel wall. It mainly includes the butt joint between aluminum alloy bulkhead and marine steel bulkhead, and the butt joint between aluminum door and marine steel bulkhead.