Materials - multiple choice 1

Question 1

Preheating for arc welding applies to:

a. Assembly welding only
b. Assembly and tack welding
c. Joints over 25 mm thick only
d. Cruciform welds only

Answer 1

b. Assembly and tack welding

Question 2

2. Which one of the following statements is correct?
   a. Preheating increases hardness
   b. Preheating increases cooling
   c. Preheating increases dilution
   d. Preheating increases shrinkage stress

Answer 2

C. Preheating increases dilution

Question 3

One of the reasons for excluding hydrogen from the weld metal is to prevent the weld from:
a. Cracking
b. Cooling slowly
c. Cooling quickly
d. Expanding

Answer 3

A. Cracking

Question 4

When a metal regains its original shape when a stress acting upon it is removed, the metal is said to have:
a.Ductility
b. Plasticity
с.Malleability
d.Elasticity

Answer 4

D. Elasticity

Question 5

The predominant structure of an hyper-eutectoid steel that has been quenched at above its upper critical point will be:
a. Austenite
b. Martensite
C.Troostite
d. Sorbite

Answer 5

B. Martensite

Question 6

When weld metal refinement takes place in a multi-run deposit, it is known by the term:
a, Weld annealing
b. Weld refining
c. Weld normalizing
d. Weld recrystallisation

Answer 6

B. Weld refining

Question 7

Welds made with high heat imputs show a reduction in which of the following properties?
a. Ductility
b. Toughness
c. Fatigue strength
d. Mechanical strength

Answer 7

B. Toughness

Question 8

A steel described as QT will have improved tensile properties because it has:
a..Had control of chemical composition
b. Been heat-treated
C.Been quality tested
d. Been vacuum melted

Answer 8

A. Had control of chemical composition

Question 9

In the welding of austenitic stainless steels, the electrode and plate material can be purchased with low carbon contents. The reason for this is to prevent:
a. Cracking
b. The formation of chromium carbides
C.Cracking in the weld metal
d. Distortion

Answer 9

C. Crack in the weld metal

Question 10

In a steel that has improved creep properties at elevated temperatures, which one of the following elements helps in this improvement?
a. Tungsten
b. Manganese
C.Molybdenum
d. Carbon

Answer 10

C.Molybdenum

Question 11

Cracks in welds may be due to:
a. Solidification problems
b. Hydrogen problems
c. Excessive stresses
d. All the above

Answer 11

D. All the above

Question 12

Welding procedures may require welds to be deposited at a controlled rate of heat input. High heat inputs would:
a. Have poor profile
b. Have larger grain size
c. Have high hardness in the HAZ
d. Have low elongation properties

Answer 12

B. Have larger grain size

Question 13

Welding of a steel plate with a CE of 0.45 would require preheating to:
a. Prevent the formation of sulphides
b. Prevent hardening in the HAZ
C. Prevent the formation of carbides
d. To improve mechanical properties in the weld

Answer 13

B. Prevent hardening in the HAZ

Question 14

A metallurgical problem most associated with submerged arc welding is:
a. Hydrogen cracking in the HAZ
b. Solidification cracking in the weld metal
c. Hydrogen cracking in the weld metal
d. Lamellar tearing in the weld metal

Answer 14

C.hydrogen cracing in the weld metal

Question 15

A large grain structure in steels is said to produce:
a. Low ductility values
b. Low fracture toughness values
c. High fracture value values
d. High tensile strength

Answer 15

b. Low fracture toughness values

Question 16

Hydrogen cracking in the weld metal is likely when welding:
a. Carbon manganese steels
b. Stainless steels
c. Micro alloyed steels (HSLA)
d. Low carbon steels

Answer 16

c. Micro alloyed steels(HSLA)

Question 17

The important point of high temperature steels is that:
a. They can withstand creep failure
b. They may suffer re-heat cracking problems
c. They may suffer loss of toughness
d. All the above

Answer 17

D. All the above

Question 18

An austenitic stainless steel may suffer:
a. Weld decay
b. Sensitisation
c. Solidification cracking
d. All the above

Answer 18

d. All the above

Question 19

Carbon equivalent values are useful to determine:
a. Weldability aspects
b. Crack sensitivity aspects
c. Typical mechanical properties
d. All the above

Answer 19

C. Typical mechanical properties

Question 20

Which of the following elements has the greater effect on the hardenability of a steel plate?
a. Molybdenum
b. Chromium
C. Titanium
d.Carbon

Answer 20

D. Carbon