Random lecture

Question 1

What is hammerscale?

Answer 1

Inclusions which have been hammered out

Question 2

What was the difference between the lowlands and highlands of GB?

Answer 2

Lowlands had a more sophisticated culture, potentially due to proximity to the Continent; highlands were mostly agricultural, with lots of bog iron; highlands = Wales, Lake District, Scotland; lowlands = south, southeast, midlands

Question 3

What is significant about the currency bar artefact?

Answer 3

Is a very heterogenous material

Question 4

When was the Delphi iron pillar constructed?

Answer 4

~400BC

Question 5

How was the Delphi iron pillar likely constructed?

Answer 5

Disks of iron beat out like in blooming process; disks placed together and fused; continuous structure formed

Question 6

Why might the Delphi iron pillar have not corroded yet?

Answer 6

Crystalline iron hydrogen phosphate hydrate forming due to the high phosphorous content = does not react with atmosphere; may be very pure so that there is no inclusions for corrosive reactions

Question 7

What is the composition of cast iron?

Answer 7

3.5-4% C

Question 8

Why is the C content of cast iron higher than wrought iron?

Answer 8

Is liquid, so has higher rate of diffusion = higher C content

Question 9

What are the three microstructures of cast iron?

Answer 9

Comprised of ferrite and graphite: flake, spherical, and compacted grey cast irons

Question 10

How does a Catalan Forge work?

Answer 10

Header tank accumulates water from rain; water dropped down drain; compresses air; air forced into furnace; enable higher temperatures to be reached; still uses charcoal

Question 11

What does a Catalan Forge produce?

Answer 11

Produces pig iron: sow = central ingot; pigs = run offs; is somewhat undesirable due to the high C pick-up caused by liquid Fe from high temperatures; occurs at ~1200-1300 Celsius

Question 12

What is unusual of the Iron Bridge?

Answer 12

Is made of cast iron, yet has structure of a wooden bridge due to the lack of knowledge regarding building with cast iron; members are separately forged

Question 13

How was the currency bar formed?

Answer 13

Likely forge-welded from smaller fragments of iron with varying microstructures; although fragments are homogeneous, the bar is heterogeneous; if the bar can be bent into a socket, was ductile and thus likely high quality