Deck 27: Weldability of Metals

Question 1

Which of the following is not a common defect if the wrong filler metal is selected for a weld?

A) Porosity
B) Cracks
C) Underfill
D) Filler metal that just will not stick

Answer 1

C

Question 2

To improve weldability in stainless steel, the carbon content should not be more than ____ %.

A) 0.03
B) 0.30
C) 3.0
D) 30.0

Answer 2

0.03

Question 3

If the chromium-nickel content of a stainless steel is referred to as 25-12, then it contains ____.

A) 25% nickel and 12 percent chromium
B) 75% chromium and 8 percent nickel
C) 25% chromium and 12 percent nickel
D) 75% nickel and 8 percent chromium

Answer 3

C

Question 4

Low-carbon steel has a carbon content of less than ____ %.

A) 0.15
B) 0.30
C) 0.50
D) 30

Question 5

In the AISI system, the letter ____ indicates basic open-hearth or electric furnace steel and basic oxygen furnace steel.

A) C
B) E
C) F
D) O

Question 6

The weight of magnesium is ____ that of steel, and ____ that of aluminum.

A) 1/4, 1/2
B) 1/4, 2/3
C) 1/3, 2/3
D) 1/2, 2/3

Question 7

Which of the following is a stainless steel alloy group?

A) Chromium alloy
B) Nickel chromium
C) Manganese alloy
D) Ferritic

Question 8

Which type of cast iron is the most widely used?

A) Gray
B) White
C) Malleable
D) Alloy

Question 9

High-carbon steels usually have a carbon content of ____ %.

A) 0.30
B) 0.30 to 0.50
C) 0.50 to 0.90
D) 30 to 90

Question 10

Why must metal that is below 70°F (20°C) be preheated before welding?

A) If the metal is too cold, you cannot get a weld pool established.
B) Because the cold metal quenches the weld.
C) The arc on cold metal is not stable, and it will wander around the surface making it hard to keep the weld going along the joint.
D) The hot metal on the cold plate will not stick, it just bounces off.

Question 11

For steels containing more than ____ % carbon, preheating and subsequent heat treatment generally are required to produce a satisfactory weld.

A) 0.30
B) 0.40
C) 30
D) 40

Question 12

Medium-carbon steel has ____ % carbon content.

A) 0.30
B) 0.30 to 0.50
C) 30
D) 30 to 50

Question 13

What is the most common preheating temperature range for most steels?

A) 250°F to 400°F (120°C to 200°C)
B) 50°F to 100°F (10°C to 37°C)
C) 350°F to 650°F (170°C to 340°C)
D) 65°F to 145°F (18°C to 62°C)

Question 14

In both steel classification systems, the first number often, but not always, refers to the ____.

A) most appropriate type of welding
B) basic type of steel
C) melting point
D) carbon content

Question 15

Chromium carbides form when the metal is between ____ Fahrenheit.

A) 200 ° and 500º
B) 500 ° and 800º
C) 800 ° and 1500 °
D) 1500 ° and 2000 °

Question 16

The strength of ____ stainless steels is the result of a special heat treatment.

A) ferritic
B) austenitic
C) martensitic
D) precipitation hardening

Question 17

The carbon content of high-manganese steel is ____ %.

A) 0.01 to 0.14
B) 0.30 to 0.50
C) 0.50 to 0.90
D) 1 to 1.4

Question 18

Most welding processes produce a(n) ____ in which the metals are heated over a range of temperatures.

A) thermal cycle
B) fusion cycle
C) interpass temperature
D) phase change

Question 19

When welding tool steel using the gas welding method, the rods selected for welding repairs should have ____.

A) a carbon content matching the base metal
B) a much higher carbon content than the base metal
C) a slightly higher carbon content than the base metal
D) a much lower carbon content than the base metal

Question 20

Pure aluminum melts at ____ Fahrenheit.

A) 1200 °
B) 1500 °
C) 1800 °
D) 2200 °

Question 21

Why must all surface contamination be removed before making a repair weld?

A) Exposure to materials released during welding can harm your health.
B) Some chemicals can be completely safe until they are exposed to the welding.
C) The smoke or fumes contamination produces can be an irritant to the skin or eyes.
D) All of the above

Question 22

Two of the most important properties of the nonferrous metal ____________________ are its extremely high strength-to-weight ratio (in alloy form) and its generally excellent corrosion resistance.

Question 23

____________________ steels are used because of increasing demand for high strength and less weight.

Question 24

How can cracks in martensite be prevented?

Question 25

What is the major purpose of pre- and post-heating cast iron for welding?

A) To allow the weld to fuse deeper into the joint
B) To control the rate of temperature change
C) To reduce the carbon content in the casting around the weld, which makes it less brittle
D) It helps the weld metal flow more evenly into the crack

Question 26

Why must some castings be repaired without pre- and postheating?

A) They are large or have to be repaired in place.
B) They are made of a type of cast iron that cannot be preheated because it is too soft.
C) It would damage the paint job on the part.
D) Cast iron repairs always require pre- and postheating.

Question 27

____________________ steels contain specified larger proportions of alloying elements.

Question 28

____________________ steel is used for wear resistance in applications involving impact, such as power shovels, rock crushers, mine equipment, and augers.

Question 29

What type of flux is required to gas weld cast iron?

A) C-flux
B) Acid flux
C) High-temperature cast iron welding flux.
D) No flux is required to gas weld cast iron.

Question 30

The most widely used stainless steels are the ____________________ types.

Question 31

Summarize the uses of chromium-molybdenum steel, including applications it is used for, processes used to weld it, and its tensile strength.

Question 32

Chromium and carbon combine to form ____________________.

Question 33

Which type of cast iron undergoes a transformation as a result of a long heat-treating process to reduce brittleness?

A) Gray
B) White
C) Malleable
D) Nodular

Question 34

The term ____________________ describes the ease with which a metal can be welded properly.

Question 35

Describe the two recommended procedures to be observed for arc welding tool steel.

Question 36

Steels alloyed with carbon and a low concentration of silicon and manganese are known as ____________________ steels.

Question 37

Explain why a part must be cleaned before repair or maintenance welding can be performed.

Question 38

____________________ stainless steels contain almost no nickel and are cheaper than austenitic steels.

Question 39

Explain the meaning of the numbers in the SAE and AISI classification systems.

Question 40

____________________ steel has a carbon content of 0.8% to 1.5%, making it very difficult to weld.