What is the difference between St52 and St52-3?

St52 and St52-3 are both grades of steel commonly used in structural applications. The primary difference between them lies in their chemical composition and mechanical properties.

St52: This grade is a low alloy, high-strength structural steel that conforms to the DIN 17100 standard. It has a minimum yield strength of 355 MPa and is typically used in construction and general engineering applications. St52 does not have any specific additional designations or requirements beyond the DIN 17100 specification.

St52-3: This grade is an enhanced version of St52, also conforming to the DIN 17100 standard. The "3" indicates that it has been normalized, which means it has undergone a controlled heating and cooling process to improve its mechanical properties. St52-3 has a minimum yield strength of 355 MPa and is known for its excellent weldability and toughness. It is commonly used in welded structures and other applications where high strength and good impact resistance are required.

In summary, while St52 and St52-3 share similar chemical compositions and basic mechanical properties, St52-3 has undergone a normalization process to enhance its mechanical characteristics, particularly its weldability and toughness.