Testing Sequence (2)

Question 1

Six basic steps for MT inspection

Answer 1

1. Part Preparation
2. Magnetization Methods
3. Application of the Particle Media
4. Inspection and Interpretation
5. Demagnetization
6. Post-Cleaning

Question 2

Part-Preparation

Answer 2

• Disassembly
• Plugging or Masking
• Pre-inspection Cleaning

Question 3

Examples of cleaning methods

Answer 3

1. detergent and aqueous
2. solvent
3. steam
4. ultrasonic
5. mechanical
6. vapour degreasing

Question 4

Detergent and Aqueous Cleaning

Answer 4

• neutral, alkaline, acidic solutions
• rinsed and dried prior to inspection
• per and post cleaning
• emulsifiers and corrosion inhibitors
• removal of light oils, grime, soil or dirt and mild grease

Question 5

Solvent Cleaners

Answer 5

• non-halogenated petroleum naphtha
• removal of moderate grease and oils
• highly portable
• may leave film or residue

Question 6

Steam Cleaning

Answer 6

• form of alkaline or detergent
• diluted solutions combined with steam in the form of a spray
• common for remote worksites

Question 7

Ultrasonic Cleaning

Answer 7

• adds ultrasonic agitation to a solvent or detergent

Question 8

Mechanical Cleaning

Answer 8

• shot, grit, sand blasting, power and manual wire brushing, metal scraping or grinding
• abrasive cleaning
• can mask fine surface discontinuities
• consider type of current being applied

Question 9

Vapour Degreasing

Answer 9

• removing heavy soils, grease and oils
• methyl chloroform and trichloroethane (historically - bad for environment)
• toxic vapours and flammable

Question 10

Variables to consider when choosing a cleaning method

Answer 10

• type of contaminants
• brittle specimen
• specimen surface condition
• accessibility
• further processing?
• cost and availability