Chapter 7,8,9 Flashcards
When molten iron is slowly cooled and the material begins to solidify, the branches that start to grow are
Dendrites
Fundamental arrangement of atoms in a space lettuce is known as
Unit cell
Which of the following structures of iron has a face centered cubic space lattice
Austenitic iron
Which of the following structures of iron has a body centered cubic space lattice
Ferrite
How many atoms are in the unit cell of a body centered tetragonal space lattice
Nine
How many atoms are in the unit cell of a close packed hexagonal space lattice
17 total atoms
A material with the large grain size is normally
Ductile
The point at which ferritin iron starts to change to Austenitic during the heating cycle is known as the blank transformation temperature
Lower
Ferrite are normally has _______ then Martensitic iron
Ductility
Structure of iron at room temperature that contains 6.67% carbon. Assume that this metal has never been heat treated.
Cementite
Name the structure of a solid solution of steel at room temperature that contains 0.8% carbon. Assume that this steel has never been heat treated.
Pearlite
Approximately how much carbon is in a sample of pure pearlite?
0.8%
What is austenite?
Steel that occurs only at elevated temperatures
What structural change occurs when steel is slowly cooled from a high temperature to room temperature?
It changes from face-centered cubic back to body-centered cubic.
Of the following types of iron-carbon, which is the hardest: Austenite, Cementite, Ferrite, and Martensite?
Martensite
Iron at 1800 F is rapidly quenched in water. What structural form of iron-carbon is the most predominant in the result if the alloy contains 0.9% carbon?
Martensite
Assume a sample of steel is cooled from an elevated temperature to 1200F and contains a very small percentage of carbon (perhaps 0.2%) The steel has not been previously heat treated. Name the new structural form of the solid solution of this steel.
Ferrite and Pearlite
Assume a sample of steel has been rapidly quenched from an elevated temperature to room temperature. It contains 0.8% carbon. Name the structural form of the solid solution of this steel.
Martensite
What point on an iron carbon phase diagram marks the intersection of the upper transformation temperature line, the lower transformation temperature line. and the pure pearlite line?
at 1300F at 0.8% carbon (Eutectoid Point)
