Hand welding practice problem_vi - Edwards @ Wiki

6 Testing and inspection of welds

Question 6.1 Requirements for quality

1. Inspection: Determination on definition and regulation
2. Test: Evaluation on definitions and regulations

• Test in conjunction with preliminary inspection of welds
  • Welding method confirmation test
  • Base metal
    • Chemical analysis test
    • Mechanical test
  • Welding construction characteristics
  • Welding rods
  • Welding device
  • Welding procedure

• Welding technician certification exam
  • Inspect and evaluate the skill of welding workers

• Types of inspections and tests at welds
  • Difference in properties between welded part and base metal
  • Weld surface
  • Surface adjacent part
  • internal

Question 6.2 Test type

1. Destructive testing: extract specimens from manufactured goods
   and test by destruction
2. Non destructive test: Test appearance and interior
   in the state of manufactured goods

Question 6.3 Weld defect

1. Crack triggers a significant decrease in joint strength

Question 6.4 Destruction test contents

1. Mechanical test: Measure breaking curves
   for tensile strength / descending point / elongation dimension (limited to welded part)
2. Bends test: Bend the front / back / side to 180 [^{circ}]
   and measure its appearance
3. (Charpy) Impact test: cut specimen into notched V shape,
   apply shock to this part and measure toughness
4. Hardness test (curability test): Measure hardness by measuring the concentrated stress portion
   of the specimen pressurized by a quadrangular pyramid

Question 6.5 Destruction test

1. Tensile test: Tensile strength and additional elongation dimension tested

Question 6.6 Destruction test: Tissue test

1. Macrostructural test: Evaluate the cross-sectional shape / penetration situation / heat affected range
   of the welded portion with a magnifying glass
2. Micro (micro: 10\times10^{-6}) organization exam:
3. Organization test classification
   1. Macro test: Visual / low magnification enlargement: examination by magnifying glass
   2. Micro test: High magnification enlargement: Examination by microscopes
4. Special note on micro test
   1. In addition to specular polishing for carbon steel tests, corrosive liquid is inspected by Nital
      Note: Nital
      5 to 10 [\%] nitric acid + alcohol solution
      Mixing ethyl alcohol to methyl alcohol is dangerous

Question 6.7 Destruction test

1. Tensile test: Inspection for material and welded joint
   1. Tensile Strength: additional stress up to break
   2. Lowering point: Primary upper limit of additional stress
   3. Extended dimension: extended dimension
      against additional stress / omitted for welded joint
2. Bending test: inspection method
   1. Test specimens including welded parts are objects
   2. Measure the appearance by applying pressure up to 180 [^{circ}]
      until the folding angle / breakage
3. Impact test
   1. In principle, test defects are processed by notching and intermittently hit
      against the back surface to measure toughness
4. Hardness test: curability test
   1. Test specimen Weld part cut surface is pressed with a quadrangular pyramid
      to measure deformed part and hardness is measured

Question 6.8 omission

1. Question 6.9 Destruction test
   1. Penetration deep scratch test
      Investigate the metallurgical structure such as cracks
      by measurement after coating treatment of test substances

1. Question 6.10 Non destructive inspection
   1. Appearance test: Evaluation for surface defects
      1. Inspection matter
         1. Product dimensions
         2. The shape of the surplus weld metal and the leg length
         3. Waveform of weld bead
         4. Welding start point and final point (crater)
         5. Welding deformation
         6. Overlap / undercut
         7. Penetration defect on back side of welding
      2. Test items
         1. Surveyed by visual inspection and equipment
   2. Proper inspection for substance internal evaluation
      1. Radiation penetration test
         1. Investigate internal defects using substance transmission characteristics
            in X-rays and \gamma-rays
         2. Detection of internal blow holes and slag
      2. Ultrasonic deep injury test
         1. Ultrasonic wave is injected into the test object and investigation
         2. Measure the position and dimension of the defect by receiving the reflection
            to the defect against the transmission of the ultrasonic wave
   3. Magnetic powder deep scratch test
      1. Utilizing magnetic flux lines attracted to the part by current flow or partial use
         of the electromagnet for the magnetic body that attracts attraction to the magnet
      2. Induces deformation of magnetic flux lines against defects on the surface,
         forms the magnetic flux lines by scattering of magnetic powder, detects abnormality

Question 6.11 omission

Question 6.12 omission

Question 6.13 omission

Question 6.14 omission

Question 6.15 omission

Question 6.16 omission

Question 6.17 omission

Question 6.18 omission

Question 6.19 omission

Question 6.20 Defect detection method

1. Surface defect: magnetic particle deep scratch test
2. Planar defect: ultrasonic deep injury test
3. Volume defect: Radiation test

Question 6.21 Proper non-destructive test for internal defects of welds

1. Radiation penetration test

Question 6.22 Appropriate non destructive test for surface defects of welds

1. Penetration deep scratch test

Question 6.23 Proper non-destructive test
for detecting internal blowhole defects in welded parts

1. Radiation penetration test

Question 6.24 Proper non-destructive test for surface crack detection of welds

1. Magnetic powder deep scratch test

Question 6.25 Non-destructive test appropriate for detection
of slag entrapment in welds

1. Radiation penetration test: volume part

Question 6.26 Non-destructive test appropriate for weld defect detection in welds

1. Appearance test

Question 6.27 Question 6.26 Non-destructive test appropriate
for detection of penetration failure of groove on weld

1. Magnetic powder deep scratch test

Question 6.26 Non-destructive test appropriate
for detection of penetration failure of groove on weld

1. Ultrasonic Deep Injury Test: Surface of Survey

Question 6.27 Non-destructive test suitable for detection
of penetration failure of groove on weld

1. Ultrasonic Deep Injury Test: Survey Running Direction

Question 6.28 Non-destructive test appropriate for undercut detection in welds

1. Appearance test

Question 6.29 Non-destructive test proper for overlap detection in welded part

1. Appearance test

Question 6.30 Non-destructive test appropriate for detection
of defective bead shape in weld zone

1. Appearance test

Question 6.31 Characteristics of radiation penetration test

1. Detection of volume defect inside
2. Detection of entrainment of slag
3. Displayed in white in the horizontal direction of the photographing plane
   with respect to the photographic film

Question 6.32 Inspection object of visual inspection

1. Presence or absence of overlap
2. Weld bead shape
3. Penetration state on the back side

Question 6.33 Characteristics of ultrasonic deep injury test

1. Detect defect by ultrasonic transmission and reception
2. Easy detection of planar defects such as fusion failure and penetration failure
3. Depth of injury method is often used for inspection
4. Difficult to distinguish defect types

Question 6.34 Characteristics of magnetic deep scratch test

1. Detection of microcracks on the weld surface is advantageous
2. The interpolar method is often used for welded parts
3. The test material is a magnetic material

Question 6.35 Characteristics of penetration deep scratch test

1. Detection of cracks and pits dominates
2. The coloring in common penetrant for test is red
3. Principle and test equipment are simple

Question 6.36 Significance of Leak Test and Pressure Test

1. Evaluate against the demand for airtight performance
2. Evaluation by leak test for water-tight requirements
3. Evaluation of pressure resistance by pressure resistance test
4. Generally, for securing safety, pressure resistance refrigerant uses water