Magnetic Particle Testing Level I Topical Outline
Total hours of instruction for this course: 12 hours
- 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 nonferrous materials
- Terminology associated with magnetic particle testing
- Characteristics of Magnetic Fields
- Bar magnet
- Ring magnet
- Effect of Discontinuities of Materials
- Surface cracks
- Scratches
- Subsurface defects
- Magnetization by Means of Electric Current
- Circular field
- Field around a straight conductor
- Right-hand rule
- Field in parts through which current flows
- Long, solid, cylindrical, regular parts
- Irregularly shaped parts
- Tubular parts
- Parts containing machined holes, slots, etc.
- Methods of inducing current flow in parts
- Contact plates
- 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
- Selecting the Proper Method of Magnetization
- Alloy, shape and condition of part
- Type of magnetizing current
- Direction of magnetic field
- Sequence of operations
- Value of flux density
- Inspection Materials
- Wet particles
- Dry particles
- Principles of Demagnetization
- Residual magnetism
- Reasons for requiring demagnetization
- Longitudinal and circular residual fields
- Basic principles of demagnetization
- Retentivity and coercive force
- Methods of demagnetization
- Magnetic Particle Testing Equipment
- Equipment selection considerations
- Type of magnetizing current
- Location and nature of test
- Test materials used
- Purpose of test
- Area inspected
- Manual inspection equipment
- Medium- and heavy-duty equipment
- Stationary equipment
- Mechanized inspection equipment
- Semiautomatic inspection equipment
- Single-purpose semiautomatic equipment
- Multipurpose semiautomatic equipment
- Fully automatic equipment
- Types of Discontinuities Detected by Magnetic Particle Testing
- Inclusions
- Blowholes
- Porosity
- Flakes
- Cracks
- Pipes
- Laminations
- Laps
- Forging bursts
- Voids
- Magnetic Particle Test Indications and Interpretations
- Indications of nonmetallic inclusions
- Indications of surface seams
- Indications of cracks
- Indications of laminations
- Indications of laps
- Indications of bursts and flakes
- Indications of porosity
- Nonrelevant indications
Magnetic Particle Testing Level II Topical Outline
Total hours of instruction for this course: 8 hours
- Principles
- Theory
- Flux patterns
- Frequency and voltage factors
- Current calculations
- Surface flux strength
- Subsurface effects
- Magnets and magnetism
- Distance factors versus strength of flux
- Internal and external flux patterns
- Phenomenon action at the discontinuity
- Heat effects on magnetism
- Material hardness versus magnetic retention
- Flux Fields
- Direct current
- Depth of penetration factors
- Source of current
- Direct pulsating current
- Similarity to direct current
- Advantages
- Typical fields
- Alternating current
- Cyclic effects
- Surface strength characteristics
- Safety precautions
- Voltage and current factors
- Source of current
- Effects of Discontinuities on Materials
- Design factors
- Mechanical properties
- Part use
- Relationship to load-carrying ability
- Magnetization by Means of Electric Current
- Circular techniques
- Current calculations
- Depth-factor considerations
- Precautions – safety and overheating
- Contact prods and yokes
- Requirements for prods and yokes
- Current-carrying capabilities
- Discontinuities commonly detected
- Longitudinal technique
- Principles of induced flux fields
- Geometry of part to be inspected
- Shapes and sizes of coils
- Use of coils and cables
- Strength of field
- Current directional flow versus flux field
- Shapes, sizes and current capacities
- Current calculations
- Formulas
- Types of current required
- Current demand
- Discontinuities commonly detected
- Selecting the Proper Method of Magnetization
- Alloy, shape and condition of part
- Type of magnetizing current
- Direction of magnetic field
- Sequence of operations
- Value of flux density
- Demagnetization Procedures
- Need for demagnetization of parts
- Current, frequency and field orientation
- Heat factors and precautions
- Need for collapsing flux fields
- Equipment
- Portable type
- Reason for portable equipment
- Capabilities of portable equipment
- Similarity to stationary equipment
- Stationary type
- Capability of handling large and heavy parts
- Flexibility in use
- Need for stationary equipment
- Use of accessories and attachments
- Automatic type
- Requirements for automation
- Sequential operations
- Control and operation factors
- Alarm and rejection mechanisms
- Multidirectional units
- Capability
- Control and operation factors
- Applications
- Liquids and powders
- Liquid requirements as a particle vehicle
- Safety precautions
- Temperature needs
- Powder and paste contents
- Mixing procedures
- Need for accurate proportions
- Ultraviolet radiation type
- Ultraviolet radiation and fluorescence
- Visible light and black light comparisons
- Requirements in the testing cycle
- Techniques in use
- Light-sensitive instruments
- Need for instrumentation
- Light characteristics
- Types of Discontinuities
- In castings
- In ingots
- In wrought sections and parts
- In welds
- Evaluation Techniques
- Use of standards – e.g. ASTM E 1444, E 709
- Need for standards and references
- Comparison of known with unknown
- Specifications and certifications
- Comparison techniques
- Defect appraisal
- History of part
- Manufacturing process
- Possible causes of defect
- Use of part
- Acceptance and rejection criteria
- Use of tolerances
- Quality Control of Equipment and Processes
- Malfunctioning of equipment
- Proper magnetic particles and bath liquid
- Bath concentration
- Settling test
- Other bath-strength tests
- Tests for ultraviolet radiation intensity