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Called / A.K.A.: P.M.I.
by X-Ray fluorescence
Date Issued: May 7th 1992
Implemented as from: June 7th 1992
Author: M. R. Packer
Date: June 9, 1992
Reviewed by: Harold Lloyd Hinds Jr.
Context: LDi 9001 Procedures 14
Revision Number: 93Oct01
Outline of changes made: Addition of Re-identification of
obscured Ht # or certificates.
In conjunction with Standards: Suitability for Purpose ISO 9000, Plan Pt.
I and work instructions Pt. III . DIN 50 049 3.1b purchase method.
Controlled copies For Attn Of: Manual Part III records, Martin
R. Packer President, H.L.Hinds Materials Control, Q.A. opps. Wk.Instrs.
PtIII, M. D. Charles LDi UK.
Incorporating by reference: Cianflone Scientific Instrument
Corporation, Instruction Manual for Model 2501, and Operation Manual CSIS
Portaspec Control Software Version 1.0
Purpose:
To provide a formal written dated record of circumstances
and method/s used to ensure, that materials received are identified with
Materials test reports before such material leave "incoming quarantine area"
or "smalls cages". The purpose is to remove the need for heat number transfer
at each machining operation. To remove this need by identification after
machining and or at final assembly. To provide assurance to third party
inspectors: so that the number of hold points within a contract may at the
client's discretion be reduced.
To ensure before shipment that only those materials issued
to meet specifications are those from which the parts have definitely been
made.
Equipment and characteristics:
Portaspec X-Ray Spectrograph 2501 with software Version
1.0.
- An x-ray tube directs a beam of primary radiation
onto the material which has been positioned under the window of the
"probe head" for analysis.
- The radiation generated by the Portaspec is directed
at the material, which causes the material to emit a secondary fluorescence
radiation.
- The secondary fluorescence contains a characteristic
line of each element present in the material being analyzed.
- The characteristic line of each element represents
a wave-length which is distinct for each element.
- The characteristic wavelengths decrease as the atomic
number of the element increase. Except that there is a change
in the numerical value as between K and L shells of the atom.
- The characteristic fluorescence radiation from all
the elements present in the material are directed through the source
or "divergent collimator" onto a large, single crystal.
- The crystal acts as a diffraction grating which separates
the various wavelengths emitted by the element in the material being
analyzed.
- By scanning through the entire angular range with
the detector, the presence of each element in the material can be detected
by determining the presence of radiation at the corresponding angular
position for each element.
- In short therefore, the intensity of radiation shown
on the rate meter dial on the "power supply" at each element setting
gives an INDICATION of
(a) Whether or not the element appears in the material under analysis,
and:
(b) How much of the element is present.
Warning (and appropriate safeguard):
As the principle of operation is by implication positional,
it is probable that the angle between the ray source and the material under
identification will impact on the reading made, by inference we can suspect
that the condition of the surface , rough with large peaks and valleys or
smooth with a much lower profile will not only affect the distance from
the ray source but will modify the fluorescence emission (by scatter) back
through the window. Therefore it is advisable to:
- Review the drawing of the component to be produced
from the material in question.
- Determine the expected surface profile of the finished
component in the area which you intend to use in your final identification.
- Have a piece produced from the materials to be issued,
with a surface that is similar to that expected on the finished component
area.
- Test the area as stated above.
- Use the readings from the test as the comparator
for identification of the finished component.
Word definition:
Even from one Bramer standard sample material, at one
setup in the sample draw, a series of tests at a given temperature and humidity
and time, will produce a series of different figures. These type of small
differences, but when between a material test report from the steel mill
and the reading we see, or between our before and after machining, are to
be called "Excursions" (because the word deviation and the word variation
are used for distinct other purposes in the machine software.)
Acceptance criteria:
Max Allowable "Excursions" from the percentage of an element
stated on a material test report - as against the Spectrograph reading,
or excursions from the readings taken before will be tabulated as necessary.
Tabulations are to be appendices to work instructions Part III of quality
plan, and in this case will be kept with the equipment in the "Spectrograph
2501 operators’ book"
Training / qualifications required:
Minimum of at least:
- 6 months metal working machine shop practice must
have included attention to radii and angles
- 2 months stock/inventory control
- 1 months use of tactile and visual surface finish
identification by comparators.
- 2 months PC computer experience.
- 2 sessions of minimum 3 hours each with demonstration
personnel from the equipment supplier (or their representatives). OR
3 weeks working with an operator who has all of the experience listed
in this section.
- 2 weeks FULL TIME practice identifying at least:
10 different materials to their M.T.Rs., with review of the results
by management. "Different" must include different heat numbers of the
same nominal grade of material, plus different grades and types of material.
Examples of different materials are: Tantalum, Titanium, Hastelloy,
Carpenter 20, and 316 Stainless Steel.
- Such other items of experience as may be required
by request of customers as agreed to by management. Any additional items
that management may consider advisable in: view of up-coming work or
to cover potential weakness of an individual operator.
Chain of command:
The Portaspec X-Ray Spectrograph Operator (XSO) reports
to the Material Controller (MC), the MC reports directly to the Quality
Manager (QM), the QM reports directly to the President. There is no
prohibition by this chain of command that any of the above multiple functional
responsibilities may not be fulfilled by the same person EXCEPT THAT there
must more than one person involved.
Equipment and system preparation / calibration:
To be done or supervised by no lower level than the MC.
- At least three standard pieces (Brammer or similar)
are chosen.
- Preferably these should have percentages that are
not too widely different for the element for which the calibration is
being done.
- Ideally there shall be a calibration to be used for
detection of trace element quantities, and a calibration to be used
for the detection of major element quantities.
- With the machine set at the angle for the element
specified by the machine manufacturer, the fluorescence count generated
by each of the samples is stored in software.
- The calibrating person inputs the percentage of the
element certified to be in each standard being viewed.
- The data is then stored as a graph against which
to compare THE COUNT, only for calculating the percentage by which the
count reading for the element is an Excursion in materials being identified.
- A Bramer or similar standard equivalent for each
material to be PMId must be available and with its certification.
Operation applicable to:
All incoming metal materials (as set out below), that
have not been previously PMId by LDi and are drawn from the incoming quarantine
area or smalls quarantine cages.
Plate: One at a time
have a disk of not less than a diameter of 40 mm taken from one corner that
does not remove any identification marking with QA personnel present. This
is normally done by plasma cutting. Before any other identity disks are
produced, the disk is marked with the same identification characters as
the parent material by QA personnel. The plates from which the identity
disks have been taken are returned to quarantine. In the event that
the Materials Controller determines that it will be technically detrimental
or non expeditious (or that he calls for a double check) to remove a corner,
the plate itself may be PMId.
Bar: When the length
is less than 1.25 meters and the diameter is greater than 75mm the length
is stood on end and the saw cut end is used as the surface to have the window
placed on it.
Bar that is too long to test on end:
The bar may be cut (provided that the heat number stamp is applied to each
length of the bar,) the shortened bar may then be tested on
Bar less than 75mm diameter:
An IDENTITY disk may be taken by sawing, the operator will then machine
the face of the disk to a finish, as determined under "warning item 2 above",
and the diameter turned to 40mm. to fit in the sample tray.
Bar greater than 75mm diameter:
PMI by placing it horizontally, placing the probe head with self positioning
guide shoes on top of the bar and having the window look at the circumference.
However this method may only be used to identify a bar to an M.T.R. Before
bar material that has been identified to M.T.Rs. in the above way may be
issued to a job, the first portion of the bar to be cut shall be tested
as on a flat machined face and the results recorded. These pieces shall
not bear the MC's stamp
Pip: Identify to its
M.T.R. as with bar, i.e. placed horizontally.
Disks from heavy (greater than 12mm thick) plate:
Test in the same manner as "pre-issue to a job blanks" (as above).
Weld filler material for full PMId contracts:
Heliark filler wires that are tagged both ends identified to certs, shall
be cut into 40mm lengths , be placed side by side, and welded together using
only the same filler material, to produce an identity piece that is 40mm
by 35mm approx, the surface will then be finished.
All material being released from quarantine to production
inventory: All shall have the personal stamp
of the MC applied thereto. All MTRs for material that has been PMId shall
have a corresponding record in the MC's computer under C:\RMTL directory,
the file name of which shall be the first 8 characters of the heat number.
In the case of FULL PMI contracts the file name will be the work order number
plus the major thickness dimension of the part to be produced there from.
THE MC STAMP is described as follows: Two arrows chasing themselves round
in a circular fashion with an asterisk in the center which has one radial
mark missing. AKA the "TROLE" mark - [the allusion is to Norsk one eyed
gremlin]
Operation:
The Bramer standard (or similar) of the same material
as the material designation on the M.T.Rs for the identity disk to be positively
identified is COUNT compared with the identity disk for all major elements.
To establish whether the percentage of an element is within tolerance, the
count is compared with the appropriate calibration curve.
Allowable excursions:
Addition to work instructions Quality Plan Part III for
use with Portaspec and inclusion in Spectrograph 2501 operators book.
MAJOR ELEMENT
|
IDENTITY
From MTR to piece.
class 1
class 2 |
IDENTITY
From piece to final.
class 1
class 2 |
| Nickel > 8% |
0.25% |
0.015% |
|
Chrome > 10%
|
0.40% |
0.02 % |
| Molybdenum > 9% |
1.0 % |
0.30 % |
| Titanium > 70% |
1.5 % |
0.50 % |
| Copper > 20% |
2.0 % |
0.75 % |
| Iron > 20% |
3.0 % |
1.00 % |
Post manufacture pre-assembly PMI:
Pre-assembly PMI shall be conducted on all components:
(of adequate size) prior to being assembled into finished product for Hydro
test (where the Job/Work Order states "Full PMI").
Method for re-identifying materials:
Those for which there is any doubt at all that any attached
cert or stamp is correct, and XSO proficiency test.
- Compare the material with Bramer Std. for Ni 200.
(99.53% of Nickel)
If the counts indicate more than 50% Ni go to B.
If the counts indicate less than 50% Ni go to C.
- Compare the material with Bramer Std. for Hastelloy
c276.
(15.43% copper)
If the counts indicate more than 25% Cu go to D.
If the counts indicate less than 50% Cu go to E.
- Compare the material with Bramer Std. for 316ss.
(16.5% chrome)
If the counts indicate more than 14 % chrome go to F.
If the counts indicate less than 14 % chrome go to G.
- Compare the material with Bramer Std. for Monel 400
(% Cu & % Ni)
- Compare the material with Bramer Std. Hastelloy c276
(15.45% Molibdenum)
If the counts indicate more than 16 % Mo then go to H.
If the counts indicate less than 16 % Mo then go to J.
- Compare the material with Bramer Std. for Monel 400
(31.7% Copper)
If the counts indicate more than 30% Cu, then Compare Ni for proximity
to % Ni
If the counts are close call the material nominally “Monel" and compare
against past PMI identity disks of Monel to establish which heat number
applies to the material. If the counts indicate less than 30% Cu then
go to G.
- Compare the material with Bramer Std. for Zirconium
(99.2% Zirconium)
If the counts indicate Zi at a level close to 99% then compare against
past PMI identity disks of Zi to establish which heat number applies
to the material. If the counts indicate no Zi (be sure to deduct the
background level) then go to K.
- Compare the material with Bramer Std. for Hastelloy
C276
( %, %).
If the counts indicate levels close to the Bramer Std. Then compare
the material against past PMI identity Disks of Hastelloy to establish
which heat number applies to the material.
- Compare the material with Bramer Std. for Nickel
200.
( %, %).
If the counts show no Cr and showed no Cu at D. then compare the material
against past PMI identity disks of Ultra High Nickel alloys until the
correct MTR is identified.
- Compare the material with Bramer Std. for Titanium
Gr 2
(99.6% Titanium)
If the counts indicate levels close to the Bramer Std. then compare
the material against past PMI identity disks of Titanium until the correct
MTR is identified.
Second party PMI acceptances:
Where a contract states that the product of LDI will receive
incoming PMI as a condition of acceptance:- As each piece of PMI equipment
gives a different reading of each element against each calibration record,
and each piece of equipment has Variations and Deviations, it is essential
that the procedures and differences be quantified before a contract containing
PMI acceptance criteria by the second party for incoming LDi product be
established – otherwise there will be repeated argument between the parties.
PMI is not an exact science. Positive is a subjective word, and each person's
idea of how positive they are different. Therefore---
Matching the x-ray fluorescence PMI of two parties
and traceability of rework of PMId items:
- The second party and LDi shall exchange copies of
their operating procedure.
- Three identity coupons of material similar to that
specified for use in the contract shall be produced by LDi.
- Each identity coupon shall be tested for major elements.
- The results shall be compared with the MTR for the
identity coupon material.
- The identity coupons shall be stamped with a letter.
- The results of the test will be kept by the letter.
- Two additional coupons that are of materials that
are different and easily detectable as such to the materials to be used
in the contract will be lettered also and will form part of the Coupon
Set. These two rogue identity coupons shall have the same appearance
and magnetism and approximate hardness as the non rouge identity coupons.
- The coupon set will then be sent to the second party.
- The second party will perform their own PMI procedure.
- LDi and the second party will then exchange their
results.
- Then it shall be agreed what the allowable Excursions
are between the two parties tests, for the purpose of the contract.
Record of LDi PMI Traceability and rework. For Individual
fittings as supplied by:
(What follows is an example record)
GRAYLOCK HUB WITH MARKINGS BEFORE MODIFICATION OF WELD
PREP END TO ACHIEVE BEST ACOUSTIC PULSE PREVENTION WITH MIN PRESSURE DROP.
Layout of Markings
PINK & WHITE PAINT STRIPES
(near to the weld prep) SER 0000001 etc.
(not applicable) 1.438BORE
PN H90133-150 GRAYLOC R 2 GR14 BW 2 1/2 SCH XX
SA 182-F316/316L G-2619 SO 7074600
on the rim G-2619
_____ / _____
PMI INSPECTORS STAMP APPLIED
STAMP SERIAL NUMBER __________ MOVED BACK FROM WELD PREP
EDGE TO FOLLOW INSPECTORS STAMP.
EX/EG: THE 2 1/2 SCH XXH MARKING WILL BE POLISHED OFF
AND REPLACED WITH _______________
ANY MANUFACTURERS PAINT IN THE WELD AREA SHALL BE SUITABLY
REMOVED (for example with acetone).
THE NEW BORE AT __________________ mm IS RECORDED
(but not stamped because this equates with new lower pipe schedule as marked)
SIGNED
MATERIALS CONTROLLER
the spectrograph PMI count of Mo, Cu, Cr, Ni, Fe, will
be attached here.
Repetitively PMId items that are identical in contour
shall be placed in suitably contoured Jig in order to ensure identical angle
and distance for the fluorescent count.
The design of the jig will cause the distance between
the Spectrograph X-Ray source and the items to be identical & to be constant
with respect to the contour.
Liquid Dynamics International
Issue No.: 3
Amendment No.: 0
Date: July 29, 1996
Approved: MRP
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