**Appendix A**

**LHC Interaction Region Quadrupole**

**Cold mass weld coupon tests**

[Weld Inspections on FNAL Q2a and Q2b Quadrupoles]{.underline}

[Agreement with CERN Safety Requirements]{.underline}

The schedule of tests for qualification and for production of Fermilab
Q2a and Q2b quadrupoles is consistent with the agreements reached
between CERN, Fermilab, and the US LHC Accelerator Project Office on 19
April 2000 (meeting report dated 28 April 2000 issued by M. Bona,).

Three sets of tests are discussed below:

-   **Table 1** lists the tests that support the qualification of weld
    materials and weld process. These tests were proposed by Fermilab in
    March and finalized in the meeting on 19 April 2000.

-   **Table 2** lists the tests according to ASME Section IX for
    qualification and re-qualification of welders (both equipment and
    personnel). Welders that are inactive for a period of six months
    must be re-qualified through the tests listed in Table 2.

-   **Table 3** lists the tests to be performed on each series
    production magnet. These tests support the requirements of ASME
    Section VIII and Fermilab rules for the operation of pressure
    vessels.

[Qualification of the Weld Materials and Process]{.underline}

The qualification of the weld materials and weld process for the
Fermilab Q2a and Q2b magnets takes an approach analogous to that used by
Brookhaven National Laboratory (BNL) for the RHIC magnets and accepted
by CERN for the BNL beam separation dipoles. Fermilab provided documents
to CERN in March 2000 describing the design and analyzing the
operational limits of the weld. These documents were accepted by CERN as
stated in the report of the 19 April 2000 meeting between CERN and
Fermilab.

Qualification testing will be performed on a mechanical model. The weld
geometry and weld process are identical to that of prototype and
production magnets. Coupons will be taken from the mechanical model and
weld sample tests as described in the Table 1 will be conducted to
support qualification of the weld materials and process.

In addition to the tests performed on the mechanical model, one of the
prototypes will have strain gauges applied. The gauges will be applied
before welding of the cold mass skin to verify the level of stress
obtained after welding. Since the vertical gap between the two iron
halves remains closed, the evolution of stresses during cool-down does
not need to be monitored.

#### Table 1 Weld Qualification Tests: The tests are conducted according to standards used by FNAL. Test standards used by CERN, which are comparable but not necessarily identical, are listed for reference. Weld samples are taken from the mechanical model. All tests are conducted at room temperature unless otherwise noted.

+------------------------+---------------+----------------------+----+
| ##                     | ####          | #### FNAL Standard   | #  |
| ## Qualification Tests | CERN Standard |                      | ## |
|                        |               |                      | #  |
|                        | **(for        |                      | No |
|                        | reference     |                      | te |
|                        | only)**       |                      |    |
+------------------------+---------------+----------------------+----+
| **Tests on Mechanical  |               |                      |    |
| Model**                |               |                      |    |
+------------------------+---------------+----------------------+----+
| ###                    | EN 970 (test) | FNAL ES-369730       | 1  |
| ### Visual inspection  |               |                      |    |
|                        | ISO 5817      |                      |    |
|                        | (acpt)        |                      |    |
+------------------------+---------------+----------------------+----+
| Delta ferrite test     |               | AWS A 4.2 (test)     | 2  |
+------------------------+---------------+----------------------+----+
| **Tests on Weld        |               |                      |    |
| Samples**              |               |                      |    |
+------------------------+---------------+----------------------+----+
| ####                   |               | ASME Sec. IX,        | 3  |
| ## Visual examination  |               | QW-302.4 (test)      |    |
|                        |               |                      |    |
| (*macro-examination)*  |               | ASME Sec. IX, QW-194 |    |
|                        |               | (acpt)               |    |
+------------------------+---------------+----------------------+----+
| Transverse tensile     | EN 895 (test) | ASTM E 8M (test)     | 4  |
| test                   |               |                      |    |
|                        | EN10002-1     | ASME Sec IX, QW-153  |    |
| *300 K, 77 K, and 4.2  | (acpt)        | (acpt)               |    |
| K*                     |               |                      |    |
+------------------------+---------------+----------------------+----+
| Impact test            | EN 875 (test) | ASTM E 23-96 (test)  | 5  |
|                        |               |                      |    |
| *300 K, 77 K, and 4.2  | ISO 148       | ASME Sec. VIII,      |    |
| K*                     | (test)        | UG-84 (acpt)         |    |
|                        |               |                      |    |
| *3 required in heat    | EN 10045-1    |                      |    |
| affected zone*         | (test)        |                      |    |
|                        |               |                      |    |
| *3 required in welded  |               |                      |    |
| metal*                 |               |                      |    |
+------------------------+---------------+----------------------+----+
| Fracture toughness     |               | ASTM E 1737-96       | 6  |
| test                   |               | (test)               |    |
|                        |               |                      |    |
| *300 K, 77 K, and 4.2  |               |                      |    |
| K*                     |               |                      |    |
+------------------------+---------------+----------------------+----+
| Radiographic (x-ray)   |               | ASME Sec. IX,        | 7  |
| test                   |               | QW-302.2 (test)      |    |
+------------------------+---------------+----------------------+----+

[Notes on tests listed in Table 1 -- Weld Qualification
Tests]{.underline}

1.  Visual inspection: Each pass of each weld will be visually inspected
    along its full length. Fermilab will specify the acceptance in a
    written engineering specification.

2.  Delta ferrite test: This test was proposed by Fermilab to support
    qualification. AWS A 4.2 is a standard of the American Welding
    Society. Delta ferrite measurements are taken of the weld at
    discrete points along the magnet. Fermilab will establish a written
    standard for the spacing between discrete points and the maximum
    acceptable ferrite number for the GTAW process.

3.  Visual examination: This test was proposed by Fermilab and required
    by ASME Sec. IX to check the depth of weld penetration.

4.  Tensile test: This test was proposed by Fermilab to support
    qualification. Uniaxial tensile testing on welds at 300 K, 77 K, and
    4 K will be conducted to determine the yield strength and ultimate
    tensile strength of the weldments. According to ASME Section IX
    (QW-153) the weld specimens must have an ultimate strength not less
    than the minimum specified strength of the base material. For 304
    stainless steel, Table UHA gives a minimum required tensile strength
    of 550 MPa.

5.  Impact test: This additional test was included by agreement between
    CERN and Fermilab. Charpy V-notch specimens will be impact tested at
    300 K, 77 K, and 4.2 K. Three specimens from the weld and three from
    the heat affected zone will be tested at each temperature. According
    to UG-84, welded specimens must have a Charpy impact energy not less
    than the minimum specified impact energy of the base material. For a
    minimum tensile strength of 550 MPa, the required average impact
    energy of three samples is 27 J/cm^2^ with a minimum impact energy
    of any one of the specimens of 20 J/cm^2^.

6.  Fracture toughness test: This test was proposed by Fermilab to
    support qualification at cryogenic temperatures. Notched specimens
    will be tested at 300 K, 77 K, and 4.2 K to characterize the
    toughness of the weld material. From the fracture mechanics analysis
    submitted to TIS (TD-00-025), we require a weld material with
    fracture toughness greater than 85 MPa m.

7.  Radiographic test: This test was added by Fermilab to further
    support qualification. The weld samples that will be taken from the
    mechanical model will be inspected radiographically. ASME Section IX
    will be used as a guide for the test and inspection of the samples.
    The radiographic inspector will be asked to identify rounded
    indications and linear indications (cracks, incomplete fusion,
    elongated inclusions). The inspector will be asked to estimate their
    sizes.

[Welder Qualification and Re-qualification]{.underline}

Qualification and re-qualification of the welding equipment and
personnel will be according to the requirements of ASME Section IX.
Re-qualification is most often required due to a period of inactivity of
six months or more, usually resulting from an interruption in
production. Coupons will be taken from run-offs made during welder
qualification (or re-qualification). Tests as described in the Table 2
will be conducted to support welder qualification or re-qualification.

Table 2 Welder qualification and re-qualification tests. The tests are
conducted according to standards used by FNAL. Test standards used by
CERN, which are comparable but not necessarily identical, are listed for
reference. All tests are done at room temperature.

+------------------------+---------------+---------------------+------+
| #### Weld              | ####          | #### FNAL Standard  | #    |
| er Qualification Tests | CERN Standard |                     | ###  |
|                        |               |                     | Note |
|                        | **(for        |                     |      |
|                        | reference     |                     |      |
|                        | only)**       |                     |      |
+------------------------+---------------+---------------------+------+
| **Tests on Weld        |               |                     |      |
| Samples**              |               |                     |      |
+------------------------+---------------+---------------------+------+
| Visual examination     |               | ASME Sec. IX, QW    | 1    |
|                        |               | -302.4 (test)       |      |
|                        |               |                     |      |
|                        |               | ASME Sec. IX,       |      |
|                        |               | QW-194 (acpt)       |      |
+------------------------+---------------+---------------------+------+
| Bend test              | EN 910 (test) | ASME Sec IX         | 2    |
|                        |               |                     |      |
|                        | ISO 7438      | QW-462.3 (b) (test) |      |
|                        | (test)        |                     |      |
|                        |               | ASME Sec IX QW-163  |      |
|                        |               | (acpt)              |      |
+------------------------+---------------+---------------------+------+

[Notes on tests listed in Table 2 -- Welder Qualification
Tests]{.underline}

1.  Visual examination: This test is proposed by Fermilab and required
    by ASME Sec. IX to check the depth of weld penetration.

2.  Bend test: This test is required by ASME Section IX to determine the
    degree of soundness and ductility of weld joints. ASME requires the
    bend specimens have no open defects in the weld or heat affected
    zone exceeding 1/8 in (3.2 mm), measured in any direction on the
    convex surface of the specimen after bending.

[Production Testing]{.underline}

No destructive tests are required for the Q2a and Q2b magnets. The
production welds will be tested as indicated in Table 3.

The four run-offs from each production magnet will be saved and
archived. Each run-off will be approximately 150 mm in length along the
weld and labeled with the magnet number and location. The run-offs will
become included with the engineering file supplied with each magnet.

Table 3 Production tests on series Q2a and Q2b quadrupoles. The tests
are conducted according to standards and procedures used by FNAL. Test
standards used by CERN, which are comparable but not necessarily
identical, are listed for reference. All tests are conducted at room
temperature unless otherwise noted.

+-------------------------+----------------+--------------------+-----+
| ####  Production Tests  | ####           | #### FNAL Standard | ### |
|                         |  CERN Standard |                    | # N |
|                         |                |                    | ote |
|                         | **(for         |                    |     |
|                         | reference      |                    |     |
|                         | only)**        |                    |     |
+-------------------------+----------------+--------------------+-----+
| **Tests on Delivered    |                |                    |     |
| Units**                 |                |                    |     |
+-------------------------+----------------+--------------------+-----+
| Visual inspection       | EN 970 (test)  | Fermilab ES-369730 | 1   |
|                         |                |                    |     |
|                         | ISO 5817       |                    |     |
|                         | (acpt)         |                    |     |
+-------------------------+----------------+--------------------+-----+
| Delta Ferrite Tests     |                | AWS A 4.2 (test)   | 2   |
+-------------------------+----------------+--------------------+-----+
| Leak check              |                | Fermilab ES-107240 | 3   |
+-------------------------+----------------+--------------------+-----+
| Pressure test           |                | Fermilab ES&H 5034 | 4   |
|                         |                |                    |     |
|                         |                | ASME Sec. VIII ,   |     |
|                         |                | UG-100             |     |
+-------------------------+----------------+--------------------+-----+

[Notes on tests listed in Table 3 -- Production Tests]{.underline}

1.  Visual inspection: Each pass of each weld will be inspected along
    its full length.

2.  Delta ferrite test: This test was proposed by Fermilab to support
    qualification and will be conducted on each production unit. AWS A
    4.2 is a standard of the American Welding Society. Delta ferrite
    measurements will be taken of the weld at discrete points along the
    magnet. Fermilab will establish a written standard for the spacing
    between discrete points and the maximum acceptable ferrite number
    for the GTAW process.

3.  Leak check: This test is required by Fermilab.

4.  Pressure test: This test is required by ASME Section VIII
    Division 1. On 1 July 1999 ASME reduced the pneumatic pressure test
    requirement from 1.25 to 1.1 times design pressure. Fermilab will
    continue to pneumatically test each production cold mass to 1.25
    design pressure to remain consistent with current FNAL and CERN
    requirements.

**MATERIALS RESEARCH & ENGINEERING, INC.**

**4820 N. 63rd Street, Suite 102**

**Boulder, Colorado 80301**

**(303) 530-9090, (303) 530-9092 FAX**

**http://www.henge.com/\~mre**

**E-mail: mre@henge.com**

**Tension tests, charpy impact, AND Fracture Toughness Evaluation of
308L and 316L Weld samples at room temperature, 77k, and 4.2k**

**(PO: 532752)**

**FINAL REPORT**

**Prepared for**

## Deepak R. Chichili, Ph.D.

**FERMI National Accelerator Laboratory**

**Technical Division**

**M/S 316, P.O. Box 500**

**Batavia, IL 60510**

**Phone: (630) 840-4710**

**Fax: (630) 840-8036**

**December 18, 2000**

**Prepared by:
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**John M. Arvidson, Chief**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

#  Michael Goyack, Engineer

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**Kenneth Blount, Lead Engineer**

**GENERAL INFORMATION:**

Tension, fracture toughness, and Charpy impact specimens were machined
from 308L and 316L weld sections provided by FERMI National Laboratory.
Initial inspection of the weld of the 308L panel, shown in Figure 1,
confirmed that the weld penetration was satisfactory for machining the
requested test specimens. Inspection of the 316L material revealed
similar satisfactory weld penetration. Periodic examinations during the
machining process confirmed the weld penetration depth throughout the
panel.

![](media/image1.jpeg){width="5.9944444444444445in"
height="2.1993055555555556in"}

Figure 1. Weld Penetration at the 0-Inch Location of the 308L Panel.

Figures 2 and 3 present the specimen locations for the 308L and 316L
panels, respectively. For the 308L panel, two specimens, COW Charpy #9
and HAZ Charpy #6, were machined from areas to either side of the
section that tension specimens 1 through 5 were taken from. The
approximate locations of the FERMI marked sections of A, B, C, and D are
indicated. Three HAZ fracture toughness specimens could not be machined
due to the narrow area indicated by the red circle in Figure 1.

Tension tests were carried out on a 20-kip electro-mechanical Instron
test frame. Load and displacement data were recorded by both computer
and plotter during each test. The speed of testing was 0.05 in/min.
During the cryogenic tests, the temperature was controlled with an
accuracy of ±2°F using liquid nitrogen (77K) and liquid helium (4K) as
the cryogenic media. A calibrated type-E thermocouple was used to verify
the temperature control. The tension specimen geometry is shown in
Figure 4.

Charpy impact tests were performed on a Tinius Olsen impact test
machine. Due to the geometry constraints of the weld section, a
0.194-inch thick impact specimen was employed. The Charpy impact
specimen geometry is shown in Figure 5.

Fracture toughness tests were conducted on weld and heat affected zone
specimens. The specimen geometry, prescribed by ASTM E1820, is shown in
Figure 6. Due to the material constraints, a sub-sized compact tension
specimen was machined (W=0.6976-inches). ASTM recommends testing a
specimen with a *W* of 2.0-inches. Cryogenic tests were carried out in a
cryostat with displacements being measured with cryogenic extensometers.
The temperature was controlled with an accuracy of ±2°F, using liquid
nitrogen (77K) and liquid helium (4K) as the cryogenic media. A
calibrated, type-E thermocouple was used to verify the actual
temperature and to maintain the temperature control. Strain
extensometers, attached to the specimen at the load line, were used to
measure the crack opening displacement (COD). Fracture toughness tests
were performed on a 22-Kip, computer controlled, hydraulic Instron test
frame. Specimen precracking was performed in accordance with ASTM E1820.
Specimens were side-grooved prior to performing the J-test.

The tension specimens for the 308L and 316L weld material are shown in
Figures 7 and 8, respectively. Figure 9 shows all Charpy impact
specimens, and Figure 10 shows a representative close-up of one Charpy
specimen. Figure 11 shows representative fracture toughness specimens
for both the 308L and 316L weld and HAZ sections.

**RESULTS**

Tension test results for the 308L weld sections are presented in Table
4, and data for the 316L weld section is in Table 5. The load versus
displacement data for the 308L tension tests appears in Figures 12
through 20. Similar curves for the 316L tension tests appear in Figures
21 through 23. The double curves seen in Figures 21 and 22 were the
result of the specimens being retested due to load pin failure. Ultimate
tensile strength values were calculated from the minimum cross-sectional
area measured before testing. Specimen T3085 failed in the center key
section, but the failure stress for the specimen is based on the minimum
area, which was not the center key section.

Ultimate tensile strength values for the 308L specimens did not display
a large degree of variability at any of the three test temperatures. The
average UTS value at room temperature was 100.6-ksi. For the 77K tension
tests, the average UTS value was 147.3-ksi, and 150.7-ksi for the 4K
tension tests.

The 316L material exhibited a higher amount of variability in the
tension test results than was seen in the 308L material. The average UTS
value for the material was 154.1-ksi at 4K. The tension specimen
geometry was chosen for conducting the tests within the geometric
constraints of the weld section. A larger grip section is required to
accommodate a larger pin diameter, which would eliminate the premature
failure of the load pin that occurred during the 316L tests.

Charpy impact data appears in Tables 3 through 5 for the 308L weld
material, the 308L heat affected zone material, and the 316L weld
material, respectively. Neither the 308L weld or HAZ material nor the
316 weld material exhibited a large degree of variability in the impact
data within individual test temperatures.

Post failure inspection of the fracture toughness samples revealed a
normal precrack surface, with no unusual off-angle, out-of-plane
behavior. However, the crack development during the J-testing proved to
be difficult in most cases. The high ductility of the material combined
with the subsized specimen geometry resulted in excessive crack blunting
during the tests. Load versus COD data monitored during the J-testing
appeared normal, but pop-in events were observed during several of the
tests.

Because of the difficulties in achieving stable crack growth during the
J-tests, post-test data analysis was performed manually and test results
are reported as J~Q~ values only. J-values presented in this report
should be used only as a comparison of each material/location tested.
They should not be used for comparison or analysis outside the scope of
this report. Materials Research and Engineering, Inc. highly recommends
that additional tests be performed on standard sized specimens to obtain
accurate J~IC~ values. Results for the J-tests appear in Table 9. Figure
24 shows the trends of the J~Q~ values as a function of temperature. The
J~Q~ values for each material increased, as expected, as the test
temperature was increased.

**RECOMMENDATIONS**

For the tension and Charpy impact specimens, additional tests must be
performed before any opinion can be formed on the precision and accuracy
of the data. Multiple specimens tested at a given temperature help
determine the scatter band for a given material. Three specimens tested
per material type and test temperature are adequate for determining the
trends in the response of the material with changing temperature, but
are **not** adequate for performing a meaningful statistical analysis.
To achieve a better representation of the material, specimens should be
chosen from different lots of material and from different locations
within each lot.

MRE recommends that additional J-tests be conducted on standard sized
fracture toughness samples with a width (W) of 2.0-inches. Specimens of
this geometry are more assured of yielding valid results. Another
important recommendation is the inclusion of additional test specimens
(six to ten) at each temperature to obtain statistically meaningful
J-value averages. This will greatly improve the understanding of J-value
versus temperature, and will help to quantify the temperature dependence
effect of fracture toughness over the entire range of selected test
temperatures.

![](media/image2.wmf){width="9.477083333333333in"
height="3.9256944444444444in"}

Figure 2. 308L Panel Specimen Locations (dimensions in inches).

![](media/image3.wmf){width="9.509027777777778in"
height="4.142361111111111in"}

Figure 3. 316L Panel Specimen Locations (dimensions in inches).

![](media/image4.wmf){width="5.333333333333333in"
height="2.0680555555555555in"}

Figure 4. Tension Specimen (dimensions in inches).

![](media/image5.wmf){width="5.333333333333333in" height="1.03125in"}

Figure 5. Charpy Impact Specimen (dimensions in inches).

![](media/image6.wmf){width="4.133333333333334in"
height="3.277083333333333in"}

Figure 6. Sub-Sized Compact Tension J~IC~ Specimen (dimensions in
inches).

![](media/image7.jpeg){width="8.304166666666667in"
height="2.4131944444444446in"}

Figure 7. 308L Tension Specimens.

![](media/image8.jpeg){width="2.457638888888889in"
height="2.5076388888888888in"}

Figure 8. 316L Tension Specimens.

![](media/image9.jpeg){width="5.940277777777778in" height="2.5in"}

Figure 9. Charpy Impact Specimens.

![](media/image10.jpeg){width="3.0in" height="0.7902777777777777in"}

Figure 10. Representative Charpy Impact Specimen.

![](media/image11.jpeg){width="5.019444444444445in"
height="3.584722222222222in"}

Figure 11. Representative Fracture Toughness Specimens.

Table 4. Tensile Data for 308L Material.

![](media/image12.wmf){width="5.999305555555556in"
height="3.922222222222222in"}

Notes:

A.  Specimen T3085 failed in the center section of the key.

Table 5. Tensile Data for 316L Material.

![](media/image13.wmf){width="5.993055555555555in"
height="1.6166666666666667in"}

![](media/image14.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 12. 308L Tension Test at Room Temperature; Specimen #1.

![](media/image15.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 13. 308L Tension Test at Room Temperature; Specimen #2.

![](media/image16.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 14. 308L Tension Test at Room Temperature; Specimen #3.

![](media/image17.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 15. 308L Tension Test at 77K; Specimen #4.

![](media/image18.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 16. 308L Tension Test at 77K; Specimen #5.

![](media/image19.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 17. 308L Tension Test at 77K; Specimen #6.

![](media/image20.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 18. 308L Tension Test at 4K; Specimen #8.

![](media/image21.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 19. 308L Tension Test at 4K; Specimen #9.

![](media/image22.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 20. 308L Tension Test at 4K; Specimen #10.

![](media/image23.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 21. 316L Tension Test at 4K; Specimen #A.

![](media/image24.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 22. 316L Tension Test at 4K; Specimen #B.

![](media/image25.wmf){width="5.995138888888889in"
height="4.0993055555555555in"}

Figure 23. 316L Tension Test at 4K; Specimen #C.

> Table 6. Charpy Impact Data for 308L Weld Material.

![](media/image26.wmf){width="7.759722222222222in"
height="3.1430555555555557in"}

> Table 7. Charpy Impact Data for 308L Heat Affected Zone Material.

![](media/image27.wmf){width="7.759722222222222in"
height="3.1430555555555557in"}

> Table 8. Charpy Impact Data for 316L Weld Material.

![](media/image28.wmf){width="7.759722222222222in"
height="1.4097222222222223in"}

Table 9. Fracture Toughness Data.

![](media/image29.wmf){width="9.305555555555555in"
height="4.223611111111111in"}

![](media/image30.wmf){width="8.386111111111111in"
height="5.448611111111111in"}

Figure 24. Fracture Toughness Versus Temperature.