Magnetic Particles Level I and II

The inspection course using Magnetic Particles explains the fundamentals by which this method is governed, thus explaining the basic principles and main applications in the industry, as well as the execution of the method will be practically demonstrated. The course meets the hours established in accordance with recommended practice SNT-TC-1A and ANSI/ASNT CP-189, issued by The American Society For Nondestructive Testing (ASNT).

  • Transmit all the theoretical and practical bases of the method, turning these into your basic foundations in your preparation for level II certification. Likewise, the participant is expected to understand and comprehend the principles of the method, its advantages and limitations, thus helping them to identify and evaluate any possible discontinuities found at the time of execution.
  • People who need to know the applications and practical knowledge of the Magnetic Particle inspection method.
  • The course for the Magnetic Particle method is a 3-day basic course, completing 20 hours of training and organized training, which is broken down with 12 hours taught for the Level I part and 8 hours for the Level II part.

LEVEL I

1.- Principles of magnets and magnetic fields.

Theory of magnetic fields.

  • Earth’s magnetic field.
  • Magnetic fields around magnetized materials.

Theory of magnetism.

  • Magnetic poles.
  • Law of magnetism.

Materials influenced by magnetic fields.

  • Ferromagnetic
  • Paramagnetic

Magnetic characteristics of non-ferrous materials.

Terminology associated with magnetic particle testing.


2.- Characteristics of magnetic fields.

  • Bar magnets.
  • ring hands.

3.- Effect of discontinuities in materials.

  • Surface cracks.
  • Scratches (Scratches or type of scratches).
  • Defects close to the surface.

4.- Magnetization by means of electric current.

Circular field.

  • Field around a straight conductor.
  • Right hand rule.
  • Parts of the magnetic field through which current flows.
  • Long, solid, cylindrical and regular parts.
  • Irregular shaped pieces.
  • Tubular parts.
  • Parts containing machined holes, slots, etc.

Methods for inducing current flow in parts.

  • Contact clamps.
  • Prods.

Discontinuities commonly discovered by circular fields.

Longitudinal field.

  • Field produced by current flow in a coil.
  • Field direction in a current-carrying coil.
  • Field strength in a current-carrying coil.
  • Discontinuities commonly discovered by longitudinal fields.
  • Advantages of longitudinal magnetization.
  • Disadvantages of longitudinal magnetization.

5.- Selection of the appropriate magnetization method.

  • Alloy, shape and condition of the piece.
  • Type of magnetizing current.
  • Direction of the magnetic field.
  • Sequence of operations.
  • Flux density value.

6.- Inspection materials.

  • Wet particles.
  • Dry particles.

7.- Principles of demagnetization.

  • Residual magnetism.
  • Reasons for requiring demagnetization.
  • Longitudinal and circular residual fields.
  • Basic principles of demagnetization.
  • Remanence and coercive force.
  • Demagnetization methods.

8.- MT. Considerations for equipment selection.

  • Type of magnetizing current.
  • Location and nature of the test.
  • Test materials used.
  • Purpose of the test.
  • Inspected area.
  • Manual inspection equipment.
  • Medium and heavy equipment.
  • Stationary equipment.
  • Mechanized inspection equipment.
  • Semi-automatic inspection equipment.
  • Single-use semi-automatic equipment.
  • Multipurpose semi-automatic equipment.
  • Fully automatic equipment.

9.- Types of discontinuities detected by MT.

  •  Inclusions
  •  Blowholes.
  •  Porosity.
  •  Flakes.
  •  Cracks.
  •  Pipes.
  •  Laminations.
  •  Laps.
  • Forging bursts.
  •  Voids.

10.- Indications and interpretations of magnetic particle tests.

  • Indications of non-metallic inclusions.
  • Indications of surface seams.
  • Indications of cracks.
  • Lamination indications.
  • Lap indications.
  • Indications for bursts and flakes.
  • Indications of porosity.
  • Indications not relevant.

Level II

1.- Principles.

  • Theory
  • Flow patterns.
  • Frequency and voltage factors.
  • Current calculations.
  • Surface flow force.
  • Subsurface effects.

2.- Magnets and magnetism.

  • Distance versus flow force factors.
  • Internal and external flow patterns.
  • Action of the phenomenon in discontinuity.
  • Effects of heat on magnetism.
  • Material hardness against magnetic retention.

3.- Flow fields.

Direct current.

  • Penetration depth factors.
  • Current source.

Pulsating direct current.

  • Similarity to direct current.
  •  Advantages.
  • Typical fields.

Alternating current.

  • Cyclic effects.
  • Surface resistance characteristics.
  • Safety precautions.
  • Voltage and current factors.
  • Current source.

4.-Effects of discontinuities in materials.

Design factors.

  • Mechanical properties.
  • Partial use.

Relationship with load capacity.

5.- Magnetization by means of Electric Current.

Circular techniques.

  • Current calculation.
  • Considerations on the depth factor.
  • Precautions, safety and overheating.

Contact tips and yokes.

  • Requirements for tips and yokes.
  • Current carrying capabilities.
  • Commonly detected discontinuities.

Longitudinal technique.

  • Principles of induced flow fields.
  • Geometry of the piece to be inspected.
  • Shapes and sizes of coils.

Use of coils and cables.

  • Field intensity.
  • Directional flow of current against flow field.
  • Current shapes, sizes and capacities.

Current calculations.

  •  Formulas.
  • Types of current required.
  • Current demand.

Commonly detected discontinuities.

6.- Selection of the appropriate method for magnetization.

  • Alloy, shape and condition of the piece.
  • Type of magnetizing current.
  • Direction of the magnetic field.
  • Sequence of operations.
  • Flux density value.

Demagnetization procedures.

  • Need to demagnetize parts.
  • Current, frequency and field orientation.
  • Heat factors and precautions.
  • Need to collapse flow fields.

7.- Team.

Portable type.

  • Laptop reason.
  • Capacities of portable equipment.
  • Similarity to stationary equipment.

Stationary type.

  • Ability to handle large and heavy pieces.
  • Flexibility of use.
  • Need for stationary equipment.
  • Use of accessories and complements.

Automatic type.

  • Requirements for automation.
  • Sequential operations.
  • Control and operation factors.
  • Alarm and rejection mechanisms.

Multidirectional units.

  •  Ability.
  • Control and operation factors.
  •  Applications.

Liquids and powders.

  • Requirements for liquid as a vehicle for particles.
  • Safety precautions.
  • Temperature needs.
  • Powder and paste content.
  • Mixing procedures.
  • Need for precise proportions.

Type of ultraviolet radiation.

  • Ultraviolet radiation and fluorescence.
  • Visible and UV light comparisons.
  • Requirements in the test cycle.
  • Techniques in use.

Instruments sensitive to light.

  • Need for instrumentation.
  • Light characteristics.

8.- Types of discontinuities.

  • In foundry.
  • In ingots.
  • In sections and forged parts.
  • In welds.

9.- Evaluation Techniques.

Use of standards, for example, ASTM E1444, E3024, E709.

  • Need for standards and references.
  • Comparison of the known with the unknown.
  • Specification and certifications.
  • Comparison techniques.

Defect evaluation.

  • History of the piece.
  • Fabrication process.
  • Possible causes of defect.
  • Use of the piece.
  • Criteria for acceptance and rejection.
  • Use of tolerances.

10.- Quality Control of Equipment and Processes.

  • Equipment malfunction.
  • Suitable magnetic particles and bath liquid.

Bath concentration.

  • Settlement test.
  • Other bath resistance tests.

Ultraviolet radiation intensity tests.