Trade Science

Question 1

A ferrous metal has a high content of…

Answer 1

Iron

Question 2

A metal that’s is yellow or red is colour is usually what type of metal

Answer 2

Copper or brass

Question 3

Given two identical pieces of metal, zinc cast and aluminum, what is the easiest way to identify them

Answer 3

By weight

Question 4

How are irregular shaped objects made

Answer 4

Casting

Question 5

True or false: soft metals like aluminum produce small broken chips

Answer 5

False

Question 6

What Rockwell scale should you use for extremely hard materials

Answer 6

Scale A for carbides and thin sheets and C for hard metals

Question 8

What are Rockwell testing penetrator tips made of

Answer 8

A&C=diamond
B=hardened ball bearing

Question 9

Define hardness

Answer 9

Ability to resist permanent deformation and penetration

Question 10

What is the outcome of annealing

Answer 10

Softer metal

Question 11

For annealing, the amount of carbon in the metal changes whether to heat the metal up above the upper critical temp or lower critical temp what percent of carbon does the temp demand change?

Answer 11

.85 percent

Question 12

Describe normalizing and why it is done

Answer 12

Normalizing removes internal strain and stress from worked steel, steel is heated to above the upper critical temp and then cooled in air

Question 13

Describe tempering and why it is done

Answer 13

Tempering removes some hardness from steel but in turn makes it more tough, tempering is done by heating the steel below the the lower critical temp and then allowing it to cool at any desired rate

Question 14

For heating metal to hardening temp, does more carbon in the steel mean a higher temp?(T or F)

Answer 14

False

Question 15

What is the structure of soft steel called and what is it made of

Answer 15

Pearlite, made from layers of ferrite and cementite

Question 16

What is the structure of hardened steel called and what is the shape of the crystals

Answer 16

Martensite, angular needle like crystals

Question 17

When steel is heated to red hot what is its new structure called

Answer 17

Austenite

Question 18

Copper and zinc when combined form a new alloy called

Answer 18

Brass

Question 19

What are the different metals that can be used to make bronze

Answer 19

Tin and phosphorous
Silicon
Beryllium

Question 20

What are the ranges for low medium and high carbon steels

Answer 20

Low: 0.02-0.3%
Med: 0.3-0.6%
High: over 0.6%

Question 21

True or false

Maraging steel uses carbon to obtain hardness

Answer 21

False, maraging steel uses other metals such as: nickel, cobalt and molybdenum to obtain hardness, carbon is considered an impurity

Question 22

What is the difference between hot rolled and cold rolled steel

Answer 22

Hot rolled has a hard oxidized outer layer, less accurate size from factory and is normally made slightly larger than advertised

Question 23

What are some basic shapes for structural steel shapes

Answer 23

C-channel, L-shapes and hollow square