M6.1

Question 1

What is a ferrous material?

Answer 1

• Contains Iron as its main ingredient
• e.g. steel on aircraft structures

Question 2

Pure iron properties?

Answer 2

• Soft
• ductile
• easily formed

Question 3

What is the base material of steel?

Answer 3

• Iron

Question 4

What is hardness?

Answer 4

• resist cutting, penetration or abrasion

Question 5

What is malleability?

Answer 5

• ability to be bent, formed, shaped without cracking or breaking

Question 6

What is brittleness?

Answer 6

• materials tendency to break or shatter when exposed to stress

Question 7

What is elasticity?

Answer 7

Materials ability to return to original shape

Question 8

What is the carbon content for low carbon steel?

Answer 8

0.1%-0.3%

Question 9

Carbon content for medium carbon steel?

Answer 9

0.3%-0.5%

Question 10

Carbon content for high carbon steel?

Answer 10

0.5%-1.05%

Question 11

What does the first digit identify in classification of steels?

Answer 11

• alloying element

Question 12

What do the last 2 digits identify in the classification of steel?

Answer 12

• average carbon content in %

Question 13

What is the critical temperature?

Answer 13

-when phase change occurs (during heating or cooling)

Question 14

What is quenching?

Answer 14

-rapidly cool material after heating in water or oil etc

Question 15

What is annealing?

Answer 15

• softens steel and relieves internal stress

Question 16

What is normalising?

Answer 16

• heating steel to 38*c above upper critical limit and soaking for prescribed time
• after soaked, cool at room temp

Question 17

What is tempering?

Answer 17

• used to decrease hardness
• increasing ductility and toughness of quenched steel

Question 18

What is direct hardening?

Answer 18

• flame or induction hardening process
• steel heated very rapidly to high temp
• then cooled rapidly

Question 19

What is flame hardening?

Answer 19

• steel made of uniform composition throughout
• surface layers receive an extra heat treatment compared to core material

Question 20

What is induction hardening?

Answer 20

• whole circumference of steel is heated simultaneously by an induction coil
• once steel reached temp, current switched off, immediately quenched by jets of water

Question 21

Steels can be divided into 3 general grades which are?

Answer 21

• Austenitic
• Ferritic
• Martensitic

Question 22

What are Austenitic stainless steels referred as?

Answer 22

• 200 and 300 series stainless steel
• non-magnetic in annealed condition

Question 23

What are Ferritic stainless steels

Answer 23

• part of 400 series of stainless alloys