AH40 is a high-strength structural steel for ship hulls. Its chemical composition needs to meet specific standards to ensure that it has the required mechanical properties and corrosion resistance. The following are the main chemical components of AH40 and their content ranges:
Carbon (C): Maximum content 0.18%, one of the main alloying elements of steel, affecting the strength and hardness of steel.
Silicon (Si): Maximum content 0.5%, helps to improve the strength and corrosion resistance of steel.
Manganese (Mn): The content range is 0.90-1.60%. For thinner steel plates (thickness ≤12.5mm), the minimum value of Mn content can be 0.70%. Manganese is an important alloying element of steel and can significantly improve the strength and hardness of steel.
Phosphorus (P): Maximum content 0.030%. Although phosphorus can improve the strength and hardness of steel, too high phosphorus content will reduce the plasticity and toughness of steel.
Sulfur (S): Maximum content 0.030%. Sulfur has an adverse effect on the mechanical properties of steel, so its content needs to be controlled.
In addition, AH40 steel may also contain the following alloying elements:
Chromium (Cr): Maximum content 0.20%, which helps to improve the corrosion resistance of steel.
Nickel (Ni): Maximum content 0.40%, which can improve the strength and toughness of steel.
Copper (Cu): Maximum content 0.35%, which has a certain effect on the mechanical properties of steel.
In addition to the above main elements, AH40 steel may also contain other alloying elements such as molybdenum (Mo), titanium (Ti), vanadium (V), niobium (Nb), etc. The addition of these elements is intended to further improve the mechanical properties and corrosion resistance of steel.
