Page 232 - Handbook of Structural Steel Connection Design and Details

Welded Joint Design and Production

Welded Joint Design and Production 217

are recorded on the PQR. According to D1.1-98, if the test results meet
all the prescribed requirements, the testing is successful and welding
procedures can be established based upon the successful PQR. If the
test results are unsuccessful, the PQR cannot be used to establish the
WPS. If any one specimen of those tested fails to meet the test require-
ments, two retests of that particular type of test may be performed with
specimens extracted from the same test plate. If both of the supplemen-
tal specimens meet the requirements, the D1.1-98 allows the tests to be
1
deemed successful. If the test plate is over 1 ⁄ 2 in thick, failure of a speci-
men necessitates retesting of all the specimens at the same time from
two additional locations in the test material.
It is wise to retain the PQRs from unsuccessful tests as they may
be valuable in the future when another similar welding procedure is
contemplated for testing.
The acceptance criteria for the various tests are prescribed in the
code. The reduced section tensile tests are required to exceed the min-
imum specified tensile strength of the steel being joined. Specific lim-
its on the size, location, distribution, and type of indication on bend
specimens are prescribed in D1.1-98, paragraph 4.8.3.3.
Writing WPSs from successful PQRs. When a PQR records the successful
completion of the required tests, welding procedures may be written
from that PQR. At a minimum, the values used for the test weld will con-
stitute a valid WPS. The values recorded on the PQR are simply tran-
scribed to a separate form, now known as a WPS rather than a PQR.
It is possible to write more than one WPS from a successful PQR.
Welding procedures that are sufficiently similar to those tested can be
supported by the same PQR. Significant deviations from those condi-
tions, however, necessitate additional qualification testing. Changes
that are considered significant enough to warrant additional testing
are considered essential variables, and these are listed in D1.1-98,
Tables 4.5, 4.6, and 4.7. For example, consider an SMAW welding pro-
cedure that is qualified by test using an E8018-C3 electrode. From
that test, it would be possible to write a WPS that utilizes E7018
(since this is a decrease in electrode strength) but it would not be per-
missible to write a WPS that utilizes E9018-G electrode (because
Table 4.5 lists an increase in filler metal classification strength as an
essential variable). It is important to carefully review the essential
variables in order to determine whether a previously conducted test
may be used to substantiate the new procedure being contemplated.
D1.1-98, Table 4.1, defines the range of weld types and positions
qualified by various tests. This table is best used, not as an after-the-fact
evaluation of the extent of applicability of the test already conducted, but
rather for planning qualification tests. For example, a test plate con-
ducted in the 2G position qualifies the WPS for use in either the 1G or
2G position. Even though the first anticipated use of the WPS may be

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