Stainless Steel

Question 1

What are some uses of stainless steel in dentistry?

Answer 1

Denture base

Ortho appliances

Question 2

What is the definition of a wrought alloy?

Answer 2

An alloy which can be manipulated/shaped by cold working

This means it can be drawn into a wire

Question 3

What do wrought alloys tend to be used for?

Answer 3

Wires (ortho)

Partial denture clasps

Question 4

What is the composition of the alloy steel?

Answer 4

> 98% iron

<2% carbon

Question 5

If ‘steel’ was to have more than 2% carbon in its composition then what would it be regarded as?

Answer 5

Cast iron or pig iron

Question 6

Apart from iron and carbon, what are some of the other ingredients in steel? What do these do?

Answer 6

Chromium -improves tarnish
Manganese - sulphur scavenger

Silicon, Nickel, Cobalt, Molybdenum

Question 7

What are some uses of steel? (in medicine)

Answer 7

Cutting instrument

Forceps

Question 8

Iron is allotropic. What does this mean?

Answer 8

That it undergoes TWO solid state phase changes with temperature

(in a solid state, it can exist in two crystalline forms (2 phases) depending on its temperature

Question 9

Below 900 degrees Celsius or above 1400 degrees Celsius, iron has what kind of structure?

Answer 9

Body centred cubic crystalline structure which has a low carbon solubility (0.05%)

Question 10

Between 900 and 1400 degrees Celsius, iron has what kind of structure?

Answer 10

Face centred cubic crystalline structure which has a higher carbon solubility (2%)