Historic steelmaking routes — naming by process Steel produced by the traditional cementation process (carburising wrought iron bars in carbonaceous material and later forging) is commonly known as which type of steel?

Introduction / Context:
Before modern basic oxygen and electric arc processes, steel was produced by several historic methods. The cementation process diffused carbon into wrought iron bars, producing a distinctive surface appearance and composition gradient. Recognizing the correct name helps link process history with microstructural characteristics.

Given Data / Assumptions:

• Cementation packs wrought iron with charcoal and heats for long durations.
• Carbon diffuses inward, raising surface carbon significantly.
• The product exhibits surface blisters from gas evolution and structural changes.

Concept / Approach:
The output of cementation is called blister steel because of the blistered surface on the carburised bars. In some routes, blister steel was subsequently melted in crucibles to homogenize composition, creating “crucible steel” (a different, later step). Thus, cementation → blister steel; melting blister in a crucible → crucible steel.

Step-by-Step Solution:
Identify process: solid-state carburising of wrought iron bars.Recognize product appearance: characteristic blisters on the bar surface.Map process to name: cementation product = blister steel.Therefore choose “blister”.

Verification / Alternative check:
Metallurgical histories consistently label cementation output as blister steel, later refined by crucible melting for uniformity.

Why Other Options Are Wrong:
“Crucible” is a subsequent refining method; Bessemer, open-hearth, and EAF are unrelated modern processes.

Common Pitfalls:
Assuming “crucible” because it is often mentioned alongside cementation; remember crucible is the secondary melting step.

Final Answer:
blister