MT Procedure for MAG50

Title: Magnetic Particle Examination Technique Procedure for wet horizontal stationary unit MAG-50

1.

PURPOSE 1.1

2.

This procedure establishes the requirements for detection of discontinuities in ferromagnetic components by using wet Fluorescent magnetic particle examination method and MAG50 horizontal wet magnetic particle stationary machine, as available in NDT shop/ /Lab.

SCOPE 2.1 The scope of this procedure nondestructive testing personnel.

3.

is

for

all

NDT

Shop/Shop/Lab

REFERENCES The following documents form a part of this procedure to the extent specified herein: 3.1

BSS7040

Boeing Specification Support Standard,

3.2

ASTM E 1444-05

Standard Practice for Magnetic Particle Inspection

3.3

SNT-TC-1A

American Society for Nondestructive Testing Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing

3.4

3.5

4.

5.

ISO 17025

AMS-2641 Base

International Organization for Standardization, General requirement for the Competence of Testing and Calibration Shop/Shop/Laboratories Vehicle, Magnetic Particle Inspection, Petroleum

3.6

AMS 3044

Magnetic Particle fluorescent wet method, oil vehicle, and Dry powder

3.7

ASTM D 445

Test Method for Viscosity of Transparent and Opaque Liquids

DEFINITIONS 4.1

Component: the part(s) or elements(s) of a system described, assembled, or processed to the extent specified by the drawing.

4.2

Final Examination: the final examination performed for the acceptance of the item. Any change tithe item's surface such as machining, grinding, welding, heat treatment, or etching by subsequent manufacturing operation, may render the previous examination invalid, requiring re-examination of all affected surfaces, unless otherwise approved in the contract.

4.3

Linear Indication: Indications with at least a three to one length to width ratio.

4.4

Rounded Indication: Indication whose length to width ratio is less than three to one

4.5

Supplier: The organization contracted to supply the materials, parts or assembly.

PROCEDURE 5.1

This procedure meets the requirements of ASME and BSS 7040 and must be accepted by the Responsible Level III.

5.2

Unless approved by the Responsible Level III, all parts will require 100% inspection. If partial inspection is performed, an illustration, either a drawing or photo of the tested area, shall accompany the NDT results.

5.3

Record Retention 5.3.1 Unless otherwise specified, all inspection documents, process control log books, equipment performance, calibration records and other documents required to produce or record inspection

conditions and results shall be retained in accordance with MSP-08 Maintaining of Quality Records. 5.4

Personnel Qualification 5.4.1 Personnel conducting Magnetic particle inspection shall be qualified and certified in accordance with Qualification and Certification Procedure for Motabaqah NDT Nondestructive Testing Personnel, which is established from the American Society of Nondestructive Testing Recommended Practice SNTTC-1A and NAS-410, latest revisions. Personnel holding Level III certification in Magnetic particle inspection shall be responsible for qualifying and certifying MOTABAQAH NDT personnel as Level I and Level II in Magnetic Particle Testing. It is the responsibility of Level I, and II Magnetic Particle personnel to perform the examinations evaluate and record the results according to this procedure.

5.5

Compliance 5.5.1 When customer purchase orders, manufacturer’s drawings or manuals, or technical orders detail the requirements for performance of the magnetic particle inspection, such as type and rate of current, they shall be followed in lieu of the requirements to this procedure. A copy of NDT requirements from governing documentation shall accompany each work order or each part when the governing documentation has specific requirements for each part. Deviation from this procedure requires approval from responsible Level III. For components processed in-house, an initial review of the part must be accomplished and Magnetic Particle Inspection Technique Sheet be completed and approved by the Responsible Level III. 5.5.1.1 Signed techniques are located in the MT Shop/Shop/Lab and are filed in ring binders folder by order of department in which the part is typically worked; top assembly number and specific part number. The index of technique sheet folder by listing each part number filed and may be used by the technician as a guide to locate the specific technique in the binders.

5.6

Examination Sequence 5.6.1 Perform magnetic particle examination after all operations, which might cause or reveal discontinuities. Such operations include, but are not limited to, forging, heat treatment,

electroplating, forming, welding grinding, straightening and machining. Perform magnetic particle examination prior to shot peening (to provide a beneficial compressive layer) and prior to applying protective finishes such as priming, painting, plating or other coatings. For in-service examination, plating or coating do not required removal prior to examination unless they are damaged or they interfere with the examination process 5.7

Preparation of Parts 5.7.1 The surface of the part to be examined shall be essentially smooth, clean, dry, and free from oil, scale, machining marks, or other contaminants or conditions that might interfere with the efficiency of the examination. If prior operations have produced a residual magnetic field that may interfere with the examination, the part shall be demagnetized.

5.8

Traceability 5.8.1 Components submitted to MT Shop/Shop/Lab shall be identified by Identification Tag, which must list part number, serial number (if applicable), part description, work order number and technician. Tag must be affixed to the part or, when not practical, placed inside a plastic bag with the part to prevent mixing of components. Prior to returning the components to the Shop, identification tags must be reattached. 5.8.1.1 When parts are submitted to the MT Shop/Shop/Lab are for inspection, the NDT Work Order Sign In Sheet, must be reviewed and parts processed on a first in/first out system unless specifically annotated as urgent.

5.9

Record of Examination

5.10 The results of all Magnetic Particle Testing shall be recorded on Result Sheet / Examination Report and returned with the components to the appropriate technician. Records shall provide for traceability to the specific part or lot examined, serial number (if serialized) and shall identify the NDT contractor or facility and the procedures used in the examination, the lot size, the number of parts accepted and include the technician's name, signature, quality inspector stamp and date of examination. Result Sheet / Examination Report are designed to certify multiple components within the same work order number. All recorded result be identified, filed and made available for review by the contracting agency upon request. In addition, a running log of daily

jobs and parts processed shall be completed. 5.10.1 Equipment shall fulfill the magnetizing and demagnetizing requirements adequately without damage to the part under examination, and it shall include the necessary features for safe operation. Demagnetizing equipment shall be capable of demagnetizing all magnetized components so that a magnetic field probe or strength meter shall not detect field with an absolute value above three gauss anywhere on the part. The equipment and material used in magnetic particle inspection shall be checked or calibrated as applicable at intervals specified in Table-I.

Table- I Test and Test Frequency Test

Reference Section

Maximum Interval FL1, FL2, FL3

Wet Particle Concentration

5.14.1

Daily or Before use

Wet Particle Contamination

5.14.1

Daily or Before use

System Performance Verification

5.15.1

Daily or Before use

Viscosity

5.16.1

When bath is adjusted

Gauss Meters Accuracy

5.17.1

Ammeter Accuracy

5.17.1 & 5.18.1

Timer Control Check

6 Months FL 4 6 Months FL 4 6 Months FL 4

5.19.1

6 Months FL 4

5.20.1

6 Months

5.21.1

Yearly/weekly

5.22.1

6 Months

5.23.1

Daily or Before use

Magnetic Field Quick Break Check Internal Short Field Indicators Black Light and White Light Meters Black Light Intensity 5.23.1 White Light Intensity 5.23.1

Daily or Before use Monthly

Ambient Light Intensity 5.17.1 & 5.21.1

FL1 Test equipment and materials whenever modification or adjustments are made. FL2 Changing local conditions, results of tests or high volume usage, may indicate more frequent tests. FL3 All equipment and materials are to pass required performance tests prior to acceptance of parts. FL4 FL5

The maximum time between verification may be extended when substantiated by actual technical/reliability data. Monitor continuously – no records required. ___________________________________________________________________

5.11 Inspection Area 5.11.1 The inspection area shall be free from residual visible light background. 5.12 New Material Conformance 5.12.1 Prior to being placed in-use, the conformance of materials shall be verified, normally by a certified report from the supplier. Wet particles shall meet the requirements of AMS 3044. The suspension vehicle shall be a light petroleum distillate conforming to AMS 2641(Type-I). Operator shall be alert to any change in performance, color, odor, consistency, or appearance of all materials in use and shall conduct the appropriate checks and tests if they have reason to believe the quality may have deteriorated. 5.13 Record of System Verification 5.13.1 The results of all system in-process verification checks shall be recorded on Register, Magnetic Particle - In-Process Verification record and be maintained in accordance with Para. 5.3.1. 5.14 Concentration and Contamination Checks 5.14.1 Particle concentration shall be determined at intervals specified in Table-I and when the bath is changed or adjusted. The contamination check may be combined and performed with concentration checks. An ASTM pear shaped centrifuge tube with a 1 ml stem; 0.05 ml increments shall be used for this check. The particle suspension shall be agitated a minimum of 30 minutes to ensure uniform distribution of particles throughout the bath. Place a 100 ml sample of the agitated suspension in the centrifuge tube, demagnetize and allow the tube to stand undisturbed for a settling time of at least 60 minutes petroleum distillate. The volume of fluorescent magnetic particle shall be 0.1 to 0.4 ml. If the concentration is out of tolerance add particle or suspension vehicle as required and re-determine the particle concentration. If the settled particles appear to be loose agglomerates rather than a solid layer, take a second sample. If the second sample also appears agglomerated, replace the entire suspension. Examine the graduated portion under both black light and visible light for striations or bands and difference in color or appearance. If the suspension has contaminants, including bands or striations that exceed 30% of the volume of magnetic particle, the bath must be adjusted or replaced. The metal chips or other foreign matter to extent that the testing sensitivity or the function of the unit is impaired.

5.15 System Performance Test 5.15.1 System Performance test shall be performed at interval specified in Table-I by using an AS 5282 Tool Steel Ring. Place a non-ferromagnetic conductor with a diameter between 1.00 to 1.25 inches and at least 16 inches long through the center of the ring and clamp between the heads. Center the ring on the conductor and place the ring so that the number one hole is at the 12 o’clock position and the other holes are facing the inspector. Attach an artificial flaw shim, Type CX, to the ring specimen approximately 0.5 inch from the number one hole, away from the inspector. Magnetize the ring circularly by passing required current through the conductor. Use the current levels specified in Table-II as applicable. Apply the suspension to the ring using continuous method and examine the ring within 1 minute after current application. Fluorescent bath shall be examined under black light conditions that meet the requirements of Para 5.23. The number of hole indications visible shall meet or exceed those specified in Table-II. Current levels used and number of holes observed may be limited by equipment current capacity and type of parts being inspected. The ring shall be demagnetized and thoroughly cleaned following the examination and checked under a black light to ensure that residual indications do not remain. Table-II Amperage and Hole Indication Requirements for AS5258 Ring Type of suspension Wet Fluorescent Oxide

5.16 Viscosity

Amperage FWDC or HWDC

Minimum Number of Holes Indicated

500

3

1000

5

1500

6

2500

7

3500

9

5.16.1 Liquid vehicle purchased with certification of conformity to AMS 2641 does not require verification of viscosity for makeup of new suspension bath. Verification of viscosity is required whenever additional liquid is added to an existing bath. The suspension viscosity shall not exceed 5 centistokes, as measured in accordance with ASTM D 445. 5.17 Equipment Calibration 5.17.1 Magnetic particle equipment shall be checked for performance and accuracy at the time of purchase and at 6month intervals thereafter, when malfunction is suspected, or when electrical maintenance that may affect equipment accuracy is performed. Equipment checks shall be made at frequencies specified in Table-I and record maintained in accordance with Para 5.3.1. The calibration of equipment shall be traceable to the National Institute of Standards and Technology (NIST) or other recognized standards, where applicable. Calibration of all current and voltage measuring devices, ammeter shunts, and gauss meter used in verification shall be calibrated in accordance with ISO17025. Equipment calibration is monitored through calibration schedule and is documented on Calibration Record Folder and Calibration Result Sheet, when applicable. 5.18 Ammeter Calibration 5.18.1 To check the equipment ammeter, a calibrated ammeter shall be connected in series with the output circuit. Comparative readings shall be taken at least three output levels encompassing the usable range of the equipment. The equipment meter shall not deviate by more than ±10% or 50 amperes; whichever is greater from the current values shown by the calibrated ammeter. This check shall be accomplished at interval specified in Table-I and in accordance with ISO 17025. 5.19 Timer control check 5.19.1 On equipment using a timer to control the current duration, the timer should be calibrated to within ± 0.1 Second using a suitable electronic timer at interval specified in Table-I 5.20 Magnetic Field Quick Break Check 5.20.1 On equipment that using a, Quick Break feature, Proper functioning of this circuit shall be verified at interval specified in Table-I. The test may be performed using a suitable

oscilloscope, commercially available tester, applicable method as specified by the manufacturer.

or other equipment

5.21 Internal Short Test 5.21.1 Stationary equipment shall be tested for internal shorts at the intervals specified in Table I. With the current control set above 1,000 amperes, the switch set on contact, and nothing clamped in the heads, activate the power to the heads. An ammeter reading above 1 or 2 (10 to 20 amps) indicates an internal short and the equipment shall be repaired prior to running production parts. Using the same settings and conduct the test again with a piece of non– conductive (wood) material clamped in the heads. An ammeter reading above 1 or 2 (10 to 20 amps) indicates an internal short and the equipment shall be repaired prior to running production parts. 5.22 Field Indicators 5.22.1 Meters used to test for residual magnetic fields shall be either: Calibrated/certified yearly, or Compared to a calibrated/certified source weekly. 5.23 Lighting 5.23.1 Black light reflectors and filters shall be checked daily for cleanliness and integrity. Dirty reflectors shall be repaired as appropriate. Replace cracked or broken ultraviolet filters immediately. Broken filters can continue to radiate ultraviolet energy and must be replaced immediately. Spectacles designed to absorb ultraviolet wavelength radiation are suggested for close, high black light intensity, examination. Fluorescent magnetic particle examinations shall be performed in a darkened area with a maximum ambient visible light level of 2-foot candles measured at the part surface. The inspection area shall be equipped with a black light, which provides a minimum intensity of 1200 microwatts per square centimeter at the surface of the part being inspected. For hand-held black lights, the intensity shall be measured 15 inches from the front of the filter to the face of the sensor. For interpretation of indications found with fluorescent magnetic particles, a white light capable of providing a minimum intensity of 100-foot candles (1000 Lux of illumination at the part surface shall be provided. Black lights, ambient and visible light shall be checked at intervals specified in Table-I or when changes occur that may cause the light intensity to change, When bulbs are replaced, both checks shall be performed prior to inspection of components. A minimum of 15 minutes shall be allowed for the black light

to obtain full brilliance before measuring the intensity. A Magnaflux Model No. MK VI Radiometer/ Photometer light meter or equivalent shall be used to measure light intensity. The light intensity meters shall be re-certified at intervals specified in Table-I and in accordance with ISO 17025. 5.24 Wet Magnetic Particle Application, Continuous Method 5.24.1 Gently spraying or flowing the suspension over the area to be examined or by immersion of the part in the suspension shall apply fluorescent particles suspended in a liquid vehicle at the required concentration. Proper sequencing and timing of part magnetization and application of particle suspension are required to obtain the proper formation and retention of indications. This requires that the stream of suspension be diverted from the part simultaneously with, or slightly before, energizing the magnetic circuit. The magnetizing current shall be applied for duration of at least half second for each application, with a minimum of two shots being used. The second shot should follow the first in rapid succession. It should come after the flow of suspension has been interrupted and before the part is examined for indications. Care shall be exercised to prevent any damage to the part due to overheating or other causes. Weakly held indications on highly finished parts are readily washed away, and hence, care must be exercised to prevent high-velocity flow over critical surfaces. 5.25 Magnetic Field Strength 5.25.1 The applied magnetic field shall have sufficient strength to produce satisfactory indications, but it must not be so strong that it causes the masking of relevant indications by non-relevant accumulations of magnetic particles. Adequate field strength may be determined by one or a combination of the following methods: 5.25.1.1 By examining discontinuities specified in the notched shims figure-1.

parts having known or artificial of the type, size, and location acceptance requirements or by using as shown in BSS7040 page No. 14,

5.25.1.2 By using a Hall Effect probe gauss meter capable of measuring the peak values of the tangential field. Tangential-filed strengths shall have a minimum value of 30 Gauss (30 X 10-4 Tesla [T]) when

measured at the part surface. Ensure that adequate field strengths are present in areas of the part to be examined. Readings in the range of 30 to 60 Gauss (30 to 60 X 10-4 Tesla [T]) are considered adequate field strength. 5.25.1.3 By using the current levels specified in Para. 5.27.1. These current levels and formulas provide only a rough guide and shall only be used in conjunction with either Para.5.25.1.1, or Para. 5.25.1.2, or LevelIII approval, or a combination thereof. 5.26 Magnetic Field Direction 5.27 Discontinuities are difficult to detect by the magnetic particle method when they make an angle less than 45 O to the direction of magnetization. To ensure the detection of discontinuities in any direction, each part must be magnetized in a minimum of two directions at approximately right angles to each other. Depending on part geometry, this may consist of circular magnetization in two or more directions, multiple circular and longitudinal magnetization, or of longitudinal magnetization in two or more directions. The flexible laminated strips as described in BSS7040 page 14 Fig. 1 or the pie field indicator as illustrated in BSS7040 page 14 Fig. 2 (Magnaflux Part Number 169799) may only be used as a tool to demonstrate the direction of the external magnetic field. 5.28 Direct Circular Magnetization 5.28.1 When magnetizing by passing current directly through the part, (that is, using head shots) the diameter of the part shall be taken as the greatest distance between any two points on the outside circumference of the part. A “rule of thumb” suggests current from 300-800 Amperes per inch of part diameter (12 to 32 A/mm) when the part is reasonably uniform and cylindrical in shape be used, but these amperages are only average current values. The lower limit of such “rule of thumb” shall be used as an initial magnetization current level. From this point, either a gauss meter and/or shim indicators shall be used to find the correct current level. Parts with multiple cross sections may have different amperages specified. Inspection sequence shall be from the lowest to the highest value given. The use of braided pads shall be used to prevent electrical arcing and burning.

5.29 Central Conductor Circular Magnetization 5.29.1 Passing current through a conductor that is positioned inside the part may provide circular magnetization. In this case, alternating current is to be used only when the sole purpose of the test is to examine for surface discontinuities on the inside surface of the part. If only the inside of the part is to be examined, the diameter shall be the greatest distance between two points, 180 degrees apart on the inside circumference. Otherwise, the diameter is determined as in 5.27.1. 5.30 Centrally Located Conductor 5.30.1 When the axis of the central conductor is located near the central axis of the part, the same current levels as given in paragraph 5.27.1 shall apply. Keep in mind the magnetizing field strength around a central conductor decreases with distance away from the conductor. The strongest flux field is present at the inner surface of the hole through which the central conductor passes. The central conductor should have an outside diameter as close as practical to the inside diameter of the hole of the part being inspected and still permit access to apply solution. 5.31 Offset Central Conductor 5.31.1 When the conductor that is positioned inside the part is placed against an inside wall of the part, the current levels given in paragraph 5.27.1 shall apply, except that the total diameter shall be the sum of the diameter of the central conductor ± twice the wall thickness of the part. The distance along the part circumference (interior) that may be effectively examined shall be taken as approximately four times the diameter o the central conductor up to 360 degrees provided the presence of suitable fields are verified. The entire circumference shall be examined by rotating the part on the conductor, allowing for approximately 10% magnetic field overlap. See Fig. 3 in ASTM E1444-05 for illustration. 5.32 Longitudinal Magnetization 5.32.1

Longitudinal magnetization is often accomplished by

passing current through a coil encircling the part, or section of the part, to be examined (that is, by using a coil shot). This produces a magnetic field parallel to the axis of the coil. The effective field extends a distance on either side of the coil center approximately equal to the radius of the coil. The actual effective distance must be demonstrated based on the particular part to be examined. For parts longer than these effective distances, the entire length shall be examined by repositioning the part within the coil, allowing for approximately 10% effective filed overlap. See Para 7.2.5.2 of BSS 7040 for formulas that can be used in coil magnetization. Note: These formulas may be used as a guide to establish preliminary magnetizing current values and shall be verified by one of the magnetic field strength monitoring methods referenced in Para 5.25.1. 5.33 Induced current magnetization (Toroidal or Circumferential) 5.33.1 Induced current magnetization is accomplished by inductively coupling a part to an electrical coil to create a suitable current flow in the part as shown in ASTM E 1444-05 figure-2. This method is often advantageous on ring shaped parts with a central aperture and with an L/D ratio less than three especially where the elimination of arcing or burning is vital importance. 5.34 Inspection 5.34.1 Following magnetization and particle application, the parts shall be examined for indications. All indications will be identified as relevant or Non-relevant. Relevant indications will be compared to accept/reject criteria and the parts accepted or rejected according. Inspection for magnetic particle indications shall be done under the lighting conditions specified in Para. 5.23.1. Personnel must wait at least 1 minute after entering a darkened area for the eyes to adjust to the low-level lighting before performing fluorescent magnetic particle examination. Longer times for more complete adaptation should be used if necessary. When using fluorescent materials, examination personnel shall not wear eyeglasses that are photo chromic or that have permanently darkened lenses. This is not intended to prohibit the use of eyeglasses with lenses treated to absorb ultraviolet light. 5.35 Non-Relevant or False Indications

5.35.1 Non-relevant indications are those that result from surface conditions, machining marks, incomplete bond between base metal and cladding etc. Also particles will adhere to certain areas created by such design factors as keyways, drilled holes or abrupt changes of section. Indications thought to be non-relevant shall be considered to be relevant until further evaluation is made. This may include surface conditioning and re-examination. Non-relevant indications that could mask relevant indications are not acceptable. Such area shall be thoroughly cleaned and reexamined. NDT technicians shall be acquainted with these and other irrelevant indications and shall be able to recognize them. 5.36 Relevant Indication 5.36.1 Relevant indications are those that result from mechanical discontinuities. All relevant indications shall be evaluated in accordance with the applicable acceptance criteria. Linear indications are indications in which the length is more than 3 times the width. Rounded indications are indications that are circular or elliptical; with the length less than 3 time the width. 5.37 Acceptance Criteria 5.37.1 Acceptance criteria shall be as specified by the customer purchase order, manufacturers’ drawings or manuals, or technical orders. Parts that contain surface discontinuities in excess of acceptance limits are unacceptable. If acceptance criteria are not specified, it shall be the absence of any relevant indications during component examination, as observed and interpreted by the operator following the procedures in this document. 5.38 Demagnetization 5.38.1 When using DC demagnetization, the initial field shall be higher than in nearly the same direction as the field reached during examination. The field shall then be reversed, decreased in magnitude, and the process repeated until an acceptable low value of residual field is reached. Whenever possible parts that have been magnetized circularly shall be magnetized in the longitudinal direction before being demagnetization. After demagnetization, a magnetic field probe or magnetic field indicator shall not detect fields with an absolute value above 3 gauss anywhere on the part. 5.39 Post Examination Cleaning

5.39.1 All parts shall be cleaned after examination. Cleaning shall be done with a suitable solvent or by other means. Parts shall be inspected to ensure that the cleaning procedure has removed magnetic particle residues from holes, crevices, passageways, etc. such residue could have an adverse effect on the intended use of the part. Parts shall be protected from corrosion or damage when required. 5.40 Serviceable Components 5.40.1 Components that have met the Magnetic Particle examination requirements and are found to be acceptable shall be marked and the marking shall be affixed to the record accompanying the component. 5.41 Unserviceable Components 5.41.1 Components that have been found to be defective during the Magnetic Particle examination shall be segregated, so as to prevent their inadvertent use or mixing with acceptable parts. They shall be identified with a red Reject/Unserviceable Tag. 5.42 Other Markings 5.42.1 Other means of identification, such as tagging, may be used for parts that have a configuration or function precluding the use of stamping, or etching. 5.43 Magnetic Particle System – Preventative Maintenance 5.43.1 On an annual basis or if contamination occurs, magnetic particle materials should be discarded and replaced with new materials. This should be done by draining the magnetic particle fluid tank and discarding the materials in accordance with Environmental, Health and Safety Standards. When changing batch numbers for the carrier or particle, new carrier should be added when tank appears to be completely empty to flush out remainder of carrier and particle that may be held in the pump. New carrier should continually be added until it runs clear out of the hose, ensuring no, in use carrier is trapped anywhere in the system. In no case should batch numbers be mixed. Turn machine off. The tank and rack should be wiped as clean as possible. Ensure and verify that the valve of the tank have been closed prior to adding new carrier. Add new carrier and turn machine back ON. Slowly add particles to the carrier according to manufacturer instructions and allow them to agitate prior to taking an initial sample in accordance with para 5.14.1. Add carrier or particles as necessary to obtain the optimum results.

Replenish the system throughout the year or as needed. In addition, a small portion of unused materials is required to be set aside for system performance checks. Prior to processing any components through the system, all applicable system and material checks should be performed.