Weldable Fine-Grain Structural Steels (Normalized)
Weldable Fine-grain Structural Steels are a family of carbon and alloy steels specially designed to provide superior mechanical properties and good weldability. They are used in applications where strength, wear resistance and good formability are needed. The two basic grades of weldable fine-grain structural steels are S275N and S355N.
S275N is a non-alloy steel with a minimum yield strength of 275MPa. It is resistant to low temperatures and has excellent weldability. It is also one of the few steels that are both weldable and formable.
S355N is a non-alloy steel with a minimum yield strength of 355MPa. It is a highly corrosion resistant steel that offers good formability and weldability. It is also a good choice for applications that are exposed to marine environments.
Both forms of weldable fine-grain structural steels can be distinguished by their chemical composition. S275N contains a lower carbon content of 0.12-0.2%, while S355N contains a higher carbon content of 0.13-0.22%. The difference between the two grades is also present in their mechanical properties. S275N has a lower yield strength of 275MPa, while S355N has a higher yield strength of 355MPa.
The welding of both forms of weldable fine-grain structural steel can be done by manual metal arc welding (MMAW), gas tungsten arc welding (GTAW) and flux-cored arc welding (FCAW). It is recommended that careful selection of the filler metals should be done to ensure that the best mechanical properties and weldability can be obtained.
Weldable Fine-grain Structural Steels are widely used in the construction of oil and gas structures, bridges, ships and offshore platforms. They are also widely used in applications where strength, wear resistance and good formability are required. Their ease of fabrication and excellent durability makes them an ideal choice for welders and engineers.
To conclude, Weldable Fine-grain Structural Steels are a specialized family of carbon and alloy steels. They are the choice of welders and engineers because they provide superior mechanical and weldability properties. They are widely used in a range of applications and are found useful in construction of bridges, ships, offshore platforms and other steel structures.
