Destructive Testing

Question 1

If a test gives you a measurable quantity what type is it?

Answer 1

Quantitative

Question 2

What does the transverse tensile test measure?

Answer 2

Strength

Question 3

Briefly describe transverse tensile testing

Answer 3

Transverse weld specimen is clamped to a machine and pulled apart until it breaks

Question 4

What formula gives the strength value in transverse tensile testing?

Answer 4

UTS = maximum load applied / original cross sectional area

Question 5

What does an all weld metal tensile yeast measure?

Answer 5

UTS, yield/proof stress and ductility

Question 6

What 2 ways are ductility measured in an all weld metal tensile test?

Answer 6

1. % elongation compared to original length
2. Reduction of area (necking)

Question 7

What best finds impact toughness?

Answer 7

Charpy v notch test

Question 8

How does the charpy v test for impact toughness?

Answer 8

By assessing the resistance to brittle fracture

Question 9

What is the transition temperature in a charpy v test?

Answer 9

The temperature where a material shifts from ductile to brittle failure

Question 10

What units does the charpy V test measure in?

Answer 10

Joules

Question 11

Describe a ductile and brittle fracture in a charpy v test

Answer 11

Brittle = bright granular crystalline

Ductile = dull and fibreous

Question 12

Charpy V also measures lateral expansion (bulge behind the specimen) what does this mean?

Answer 12

The material was tougher absorbing more energy

Question 13

What is hardness?

Answer 13

How well a material resists being permanently dented or scratched. It’s resistance to plastic deformation.

Question 14

How is hardness tested?

Answer 14

With vickers Brunel and Rockwell testing

Question 15

What does the CTOD test measure? (Crack tip open displacement)

Answer 15

Fracture toughness

Question 16

Describe the specimen and process of CTOD

Answer 16

Notched specimen with a saw cut (crack) clamped onto a machine bending back and fourth.

Question 17

How does CTOD measure fracture toughness?

Answer 17

A clip guage is placed right at the mouth of the V notch.
This precisely measures how much the mouth opens as the load is applied.

Question 18

What are the four main types of bend tests?

Answer 18

Face bend
Root bend
Side bend (over 12mm)
Longitudinal bend

Question 19

Briefly describe a fillet fracture test

Answer 19

Notch machined into centre of fillet weld
Machine presses until it breaks

Question 20

Briefly describe nick break test

Answer 20

Notch machined all the way around a butt weld coupon pressed until broken

Question 21

What is a macro test for?

Answer 21

Detailed visual inspection of a welds cross sectional

Question 22

In bend testing the diameter of a former is expressed as a multiple of the thickness, what is it typically for C-Mn? Why might materials have it greater than 10?

Answer 22

C-Mn = 4t

Materials that have lower tensile ductility

Question 23

Bend tests - are they used for just WPQR’s or welder quals aswell?

Answer 23

Both

Question 24

What is the acceptance criteria in bend tests?

Answer 24

Satisfactory soundness - some standards allow small indications less than 3mm