Aircraft Materials - Ferrous Flashcards
What temperature would steel be tempered at?
Below the annealing temperature
Tempering steel gives
Relief of internal stress after hardening
The addition of chromium to steel will produce
Hardness
Chromium added to plain carbon steel
Increases it’s resistance to corrosion
The purpose of cars hardening is to
Produce a hard case over a tough core
Nitriding is
Case hardening
Medium carbon steels have a carbon content of
0.3 - 0.5%
A ferrous metal contains
Iron
With respect to ferrous metals
Iron is the main element and most ferrous metal are magnetic
The annealing process on steel is required sometimes as it
Relieves internal stress suffered after engineering processes
Tempering entails
Heating under the UPC and slow cooling
Austenitic stainless steels are
Non-magnetic
How is residual magnetism removed after an NDT examination?
Degaussing
The difference between annealing and normalising is
Both are heated above UCT, cool slowly to anneal, cool in air to normalise
Normalising of steel is done to
Remove residual stress of the manufacturing process
When normalising, the material is
Left to cool in room temperature
Cast iron is
Heavy and brittle
Case hardening can be carried out on
Any ferrous metal
Exhaust systems are usually made from stainless steel which is susceptible to
Intergranular corrosion
When metal is first heated slightly above its critical temperature and then cooled rapidly it is common that the metal will increase in
Brittleness and hardness
Steel is tempered
After hardening
If a steel component is operated below the fatigue limit, the fatigue life is
Infinite
A low carbon steel would normally be case hardened using
Pack or gas carburising
After a product has been manufactured and all heat treatment has been carried out the stress remaining if any is termed as
Residual stress
Annealing steels
Makes the metal malleable
Tempering of hardened steel is carried out to
Significantly reduce the brittleness without suffering a major drop in its strength
High speed steel relies heavily on the following metallic element for its ability to cut other metals, even when it is heated to a dull red colour
Tungsten
When a low carbon steel bolt is stretched beyond its elastic limit without
Deform permanently
Fatigue failure may be defined as
Reduction in strength due to alternating loads
Austenitic steel is produced when the material is heated to
Above the Upper Critical Point
Steel is produced by refining pig iron where air/oxygen is blown through the molten material to remove
Carbon
During a Rockwell Hardness test, what dimension is being measured?
The depth of the indent
What does the 0 in 2024-T3 mean?
The alloy has not been modified
How is material galvanised?
Dipped in a bath of molten zinc
