Composition of wrought iron Approximately what is the percentage carbon content in wrought iron used historically for structural and fabrication purposes?

Introduction / Context:
Wrought iron is an extremely low-carbon form of iron historically valued for its ductility, forgeability, and corrosion resistance due to slag inclusions. Recognizing its carbon level distinguishes it from steels and cast irons and explains its mechanical behavior.

Given Data / Assumptions:

• “Percentage carbon content” refers to weight percent carbon.
• Typical wrought iron contains very little carbon and entrained slag stringers.
• Modern structural steels replaced wrought iron; the concept remains important educationally.

Concept / Approach:
Wrought iron’s carbon is typically about 0.02% (often below 0.08%), far less than that of steels (approx. 0.05–2.0%) and much less than cast irons (2.0–4.3%). The low carbon explains its ease of forging and low hardenability.

Step-by-Step Solution:
Define ranges: wrought iron very low C, steels intermediate C, cast irons high C.Identify the characteristic value for wrought iron ≈ 0.02%.Compare with options: 0.02% matches the classic value.Therefore select 0.02%.

Verification / Alternative check:
Standard references list wrought iron carbon content as typically 0.02% with slag content of 1–3% that provides the fibrous appearance in etched sections.

Why Other Options Are Wrong:
0.10–0.80% are steel-like or higher; 0.20% and 0.40% align with low/medium-carbon steels, not wrought iron.

Common Pitfalls:
Confusing “wrought iron” with modern “wrought-iron style” steel products; true wrought iron is no longer mass-produced but retains historical significance.

Final Answer:
0.02%