FH36 ship plate is the main grade of high-strength hull structural steel, with a yield strength of ≥355MPa and excellent comprehensive mechanical properties and fatigue resistance. Its chemical composition is characterized by low carbon (C≤0.12%), low sulfur and phosphorus (S≤0.025%, P≤0.025%), and the addition of micro-alloy elements such as niobium, vanadium, and titanium. The grains are refined through the controlled rolling and controlled cooling (TMCP) process to achieve the best match between strength and toughness.
Key performance indicators
High strength and fatigue resistance: The tensile strength of FH36 is 490-620MPa, and the fatigue life is more than 50% higher than that of ordinary ship plates. In the deck structure of large container ships, FH36 can withstand repeated cargo loads and wave impacts, reducing the occurrence of fatigue cracks.
Low temperature toughness and resistance to lamellar tearing: -40℃ Charpy impact energy ≥34J, Z-direction section shrinkage ≥25%, effectively resisting brittle fracture and lamellar tearing in the thickness direction under low temperature environment. For example, in the ice-strengthened structure of ships on the Arctic route, the Z-direction performance of FH36 can ensure the safety of the structure under ice load.
Seawater corrosion resistance: By adding alloy elements such as copper (Cu≤0.35%) and nickel (Ni≤0.80%), a dense oxide film is formed on the surface of FH36, and the seawater corrosion resistance is 2-3 times higher than that of ordinary carbon steel, which is suitable for ships serving in the marine environment for a long time.
Main application areas
Large container ships: used to manufacture high-stress parts such as decks and hatch coamings. For example, the deck structure of 24000TEU ultra-large container ships uses a large amount of FH36 steel, which reduces the deadweight by about 800 tons while ensuring structural strength.
Offshore platforms: As the material of key components such as jackets and pile legs, they withstand the harsh conditions of deep-sea environments. For example, the semi-submersible platform of a deepwater oil and gas field in the South China Sea uses FH36 steel for its pile legs, with a design service life of 30 years.
Liquefied Natural Gas (LNG) Carrier: It is used in the cargo tank support structure and hull shell of LNG carriers to ensure good toughness and strength in a low temperature environment of -163℃.
Quality Control and Certification
FH36 ship plates must pass strict certification processes, such as ABS (American Bureau of Shipping), DNV (Norwegian Classification Society), CCS (China Classification Society) and other certifications. During the production process, ultrasonic flaw detection (UT) is used to detect internal defects and magnetic particle testing (MT) is used to detect surface cracks to ensure that each plate meets high standards.
