To determine which elements do not contribute to the strength of structural steel, we need to understand the impact of each element mentioned.

Option A: Carbon

Carbon is a crucial element in steel. It increases the hardness and strength of the steel through solid-solution strengthening and the formation of carbides. It is vital in enhancing the strength and hardness of structural steel.

Option B: Manganese

Manganese is another important element in steel. It acts as a deoxidizer and helps improve toughness and hardness. In addition, manganese contributes to the wear resistance and strength of steel. Therefore, it plays a positive role in strengthening structural steel.

Option C: Sulphur

Sulphur is generally considered an impurity in steel. It tends to make the steel brittle and can adversely affect the strength and ductility. Therefore, sulphur does not contribute to the strength of structural steel and is generally kept to low levels.

Option D: Chlorine

Chlorine is not typically found in structural steel as an alloying element. It is more commonly associated with causing corrosion and degradation of steel when it is exposed to chloride environments. Chlorine does not contribute to the strength of structural steel and can in fact undermine its structural integrity.

Based on this analysis, the elements that do not increase the strength of structural steel are:

Option C: Sulphur and Option D: Chlorine

Materials and Specifications · Steel Structures · GATE CE

Marks 1