NDT Material Properties & Inspection Standards 3

Question 1

What NDT method is most effective for detecting surface-breaking cracks in ferromagnetic boiler components?

Accepted Answer

Magnetic particle testing

Answer

Ultrasonic testing

Answer

Radiographic testing

Answer

Eddy current testing

Question 2

What is 'creep' in boiler material behavior?

Accepted Answer

Slow, time-dependent plastic deformation under sustained load at elevated temperature

Answer

Sudden fracture under impact loading

Answer

Rapid corrosion in the presence of oxygen

Answer

Grain boundary attack by sulfur compounds

Question 3

According to ASME standards, what is the minimum required weld joint efficiency for a double-welded butt joint in a pressure vessel subjected to radiographic examination?

Accepted Answer

1.00

Answer

0.70

Answer

0.85

Answer

0.60

Question 4

In material science, what does the 'modulus of elasticity' (Young's modulus) represent?

Accepted Answer

The ratio of stress to strain in the elastic region

Answer

The stress at which permanent deformation begins

Answer

The energy absorbed before fracture

Answer

The maximum stress a material can withstand

Question 5

Which of the following inspection standards is used specifically for the qualification of NDE personnel in the US?

Accepted Answer

ASNT SNT-TC-1A

Answer

ASME Section V

Answer

AWS D1.1

Answer

ASTM E709

Question 6

What does 'sensitization' mean for austenitic stainless steel used in boiler applications?

Accepted Answer

Precipitation of chromium carbides at grain boundaries, reducing corrosion resistance

Answer

Increased susceptibility to hydrogen embrittlement after heat treatment

Answer

Increased hardness due to work hardening

Answer

Loss of magnetism after exposure to high temperatures

Question 7

When performing a liquid penetrant test, what is the purpose of the developer?

Accepted Answer

Draw penetrant out of discontinuities to form visible indications

Answer

Remove excess penetrant from the surface

Answer

Clean the surface prior to penetrant application

Answer

Increase the viscosity of the penetrant liquid