Cleaning And Corrosion

Question 1

Corrosion treatment requires these basic steps:

Answer 1

Remove
Neutralize
Restore/Protect

Question 2

3 basic requirements for the formation of corrosion

Answer 2

Electrical potential difference within metal.
Conductive path between areas.
Covered with Electrolyte.

Question 3

White powder which forms on the surface of aluminum when it corrodes is a…

Answer 3

Chemical Salt

Question 4

3 steps that can be taken to minimize damage from corrosion:

Answer 4

Minimize electrical potential difference.
Eliminate conductive path with insulating barrier.
Prevent electrolyte contacting metal.

Question 5

When electrolytic or galvanic corrosion occurs between an aluminum structure and steel bolt, the _____ will be the metal that is corroded.

Answer 5

Aluminum

Question 6

Another name for dry corrosion is:

Answer 6

Rust/Oxidation

Question 7

Exfoliation usually develops in _____ metal parts

Answer 7

Extruded

Question 8

Stress corrosion occurs when a part is under _____ stress in a corrosion environment.

Answer 8

Tensile

Question 9

Corrosion that forms inside a metal along the grain boundaries is called:

Answer 9

Intergranular corrosion

Question 10

Intergranular corrosion may often be detected by either of these two types of nondestructive inspections:

Answer 10

X-ray

Ultrasonic

Question 11

The scum that forms inside the fuel tanks of some jets aircrafts is caused by:

Answer 11

Microbes and bacteria in the fuel.

Question 12

Type of finish used to protect the inside of a battery box against corrosion is:

Answer 12

Polyurethane enamel

Question 13

A solution of _____ and water is used to neutralize fumes from a nickel cadmium battery.

Answer 13

Boric acid.

Question 14

A piano hinge should be lubricated with a _____ lubricant.

Answer 14

Water displacement

Question 15

Steel cables can be protected from corrosion by spraying them with a _____ lubricant.

Answer 15

Water displacement

Question 16

Penetrant inspection _____ be used on steel parts to detect a surface crack.

Answer 16

Can

Question 17

Corrosion may be removed from aluminum surfaces by scrubbing them with…

Answer 17

Nylon scrubber/ Scotch Brite

Question 18

A chemically deposited oxide film on an aluminum surface is called…

Answer 18

Alodizing

Question 19

One of the best methods for removing the corrosion products from rusted steel parts is a/an..

Answer 19

Abrasive blasting.

Question 20

Galvanizing is a method of protecting steel with a coating of?

Answer 20

Zinc

Question 21

A fully formed anodized film is…

Answer 21

Hard

Question 22

Before paint will stick to a cadmium plated surface, the surface should be etched with a solution of…

Answer 22

Chromic acid

Question 23

Highly stressed steel parts should not be cleaned by scrubbing them with a wire brush because of the danger of…

Answer 23

Stress concentrations

Question 24

Oil and grease may be removed from acrylic plastics and rubber by wiping them with a rag dampened with…

Answer 24

Aliphatic naphtha.

Question 25

List 9 types of corrosion.

Answer 25

``` Oxidation, Intergranular, Exfoliation, Stress, Galvanic, High Metallic ion concentration cell, Low Oxygen concentration cell, Fretting, Filiform, Uniform Surface ```

Question 26

Six corrosive agents:

Answer 26

``` Air Water Acidic Alkali Salt Mercury Organic Matter ```

Question 27

_____ metals are damaged almost equally by acids or alkalis, but _____ may be damaged more by a strong alkaline solution than by acid.

Answer 27

Ferrous; Aluminum

Question 28

Filiform corrosion consists of threadlike filaments of corrosion that form on the surface of metals coated with organic substances such as paint. (T/F)

Answer 28

True

Question 29

What causes intergranular corrosion?

Answer 29

Improper heat treatment

Question 30

The most fundamental and important rule for corrosion control is to?

Answer 30

Keep it clean.

Question 31

The use of non-recommended cleaning compounds can result in a condition know as…

Answer 31

Hydrogen Embrittlement.

Question 32

What causes corrosion in aircraft fuel tanks?

Answer 32

Microbes and Bacteria in the fuel.

Question 33

Cadmium plating, galvanizing and cladding protect the case metal by a process know as…

Answer 33

Sacrificial corrosion.

Question 34

An electrolytic process that forms a surface of oxide film is called “chemical treatment or alodining”. (T/F)

Answer 34

False

Question 35

What is oxidation?

Answer 35

Dry corrosion or rust

Question 36

Three types of inspection?

Answer 36

Ultrasonic, X-ray, Visual

Question 37

7 common locations for corrosion on a plane?

Answer 37

Wheel well, lavatory, battery compartment, inlets for engine, exhaust area, cables, fuel tank.