AH32 ship plate is one of the most commonly used high-strength hull structural steels in the field of shipbuilding and marine engineering. It belongs to the high-strength grade in Grade A steel (H stands for high strength, and 32 stands for the minimum yield strength of 315MPa).
Its material is based on iron, and the carbon content is strictly controlled (usually ≤0.18%) to ensure toughness. Silicon (0.10%-0.50%) and manganese (0.90%-1.60%) are used to strengthen the matrix strength. At the same time, the purity is improved through extremely low phosphorus (≤0.035%) and sulfur (≤0.035%) content.
In terms of characteristics, the yield strength of AH32 ship plate is ≥315MPa, the tensile strength is 440-570MPa, and the elongation after fracture is ≥22%, which has both strength and plasticity. Its most outstanding performance is low-temperature toughness. In the 0℃ impact test, the absorbed energy is ≥34J (Charpy V-notch), which can withstand the low-temperature impact of ships sailing in temperate and some cold waters. In terms of processing performance, the steel plate can be produced by hot rolling or controlled rolling process, with a cutting accuracy error of ≤1mm. When welding, the E4303 electrode can be used to achieve good fusion. The tensile strength of the welded joint is more than 95% of the parent material, which is suitable for large-scale assembly line operations.
The advantages are reflected in three dimensions:
1. Cost controllability: Compared with higher-grade ship plates, AH32 does not contain precious alloy elements, and the cost per ton of steel is 500-800 yuan lower, which is suitable for small and medium-sized ships and non-critical structural parts;
2. Certification compatibility: It has passed the certification of nine major classification societies such as ABS, DNV GL, and LR, and can be directly used in the construction of export ships, reducing the cost of repeated inspections;
3. Environmental adaptability: The adhesion of the galvanized layer after shot blasting is ≥70MPa, and the corrosion rate in a salt spray environment is ≤0.05mm/year, which meets the anti-corrosion needs of offshore and inland ships.
The applications cover the entire process of shipbuilding:
·Hull structure: used for outer plates (thickness 6-20mm) and deck plates (8-25mm) of cargo ships and fishing boats, bearing water pressure and cargo load;
·Cabin partition: making watertight bulkheads (thickness 4-12mm), which can withstand 0.5MPa water pressure with rubber sealing strips;
·Marine engineering: replacing ordinary carbon steel in non-pressure-bearing structures such as supporting legs and temporary oil storage tanks of offshore wind power installation platforms, reducing weight by 20% while improving corrosion resistance;
·Auxiliary equipment: such as anchor chain locker bottom plates, mooring equipment brackets, etc., to withstand anchor chain friction and seawater splash corrosion.
