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LR AH32 Marine Structural Steel

LR AH32 marine structural steel, in addition to being required to be resistant to marine atmospheric and seawater corrosion and to have sufficient resistance to cyclic fatigue strength caused by waves and tidal currents, should also be able to resist -30 Low temperature brittleness at ℃~-20℃. In addition, LR AH32 marine structural steel should also have good weldability and machinability.

LR AH32 marine structural steel is generally used for structures under horizontal loads caused by waves and strong winds, and the tensile strength is 50~60 kg/mm. In the joint part, due to stress concentration and three-dimensional stress, LR AH32 marine structural steel is required to have sufficient strength and good plastic deformation performance. If the strength is too high, it is easy to cause dangerous stress corrosion damage.

As long as the Z-direction (that is, the thickness direction) shrinkage rate of LR AH32 marine structural steel is greater than 20%, the tensile strength of LR AH32 marine structural steel in the thickness direction and the rolling direction can be basically the same. The key to improving Z-direction performance is to improve the cleanliness of LR AH32 marine structural steel, especially to reduce sulfide inclusions during smelting or to change the shape of inclusions by adding rare earth elements.

In addition, the designer should minimize the stress of LR AH32 marine structural steel in the thickness direction, such as by reasonably distributing the welds and changing the groove form of the welds or the way of connection. In addition to the preheating method, the manufacturer can also use reasonable assembly, welding procedures and other measures to reduce the stress in the thickness direction of the LR AH32 marine structural steel.