IMPACT TEST TEMPERATURE DIFFERENTIAL

Minimum Specified Temperature Difference, °F Yield Strength, ksi [Note (1)]

≤40 10

≤55 5

>55 0

NOTE:

(1) Impact test temperature may be warmer than the minimum design temperature by the amount shown.

When the part is too small to provide the three specimens of at least minimum size shown in Fig. UG-84, no impact test need be made.

UG-84(e)(3) Small Vessels. For small vessels in

conformance with U-1(j), one set of impact specimens of the material may represent all vessels from the same heat of material not in excess of 100 vessels or one heat-treatment furnace batch, whichever is smaller.

UG-84(f) Impact Testing of Welds

UG-84(f)(1) For steel vessels of welded construc-

tion the impact toughness of welds and heat affected zones of procedure qualification test plates and vessel impact test plates (production impact test plates) shall be determined as required herein.

UG-84(f)(2) All test plates shall be subjected to

heat treatment, including cooling rates and aggregate time at temperature or temperatures as established by the Manufacturer for use in actual manufacture. Heat treatment requirements of UG-85, UCS-85, UHT-81, and UHT-82 shall apply to the test plates except that the provisions of UCS-85(f) are not applicable to test plates for welds joining P-No. 3, Gr. Nos. 1 and 2 materials.

UG-84(g) Location, Orientation, Temperature, and Values of Weld Impact Tests. All weld impact tests

shall comply with the following.

UG-84(g)(1) Each set of weld metal impact speci-

mens shall be taken across the weld with the notch in the weld metal. Each specimen shall be oriented so that the notch is normal to the surface of the material and one face of the specimen shall be within 1_⁄

16 in. (1.6 mm) of the surface of the material.

UG-84(g)(2) Each set of heat affected zone impact

specimens shall be taken across the weld and of suffi- cient length to locate, after etching, the notch in the heat affected zone. The notch shall be cut approximately normal to the material surface in such a manner as to include as much heat affected zone material as possible in the resulting fracture.

UG-84(g)(3) For welds made by a solid-state weld-

ing process, such as for electric resistance welded (ERW) pipe, the weld impact tests shall consist only of one set of three specimens taken across the weld with the notch at the weld center line. Each specimen shall be oriented so that the notch is normal to the surface of the material and one face of the specimen shall be within 1_⁄

16 in. (1.6 mm) of the surface of the material. The weld impact tests are not required if the weld and the base metal have been: annealed, normal- ized, normalized and tempered, double normalized and tempered, or quenched and tempered.

UG-84(g)(4) The test temperature for welds and

heat affected zones shall not be higher than required for the base materials.

UG-84(g)(5) Impact values shall be at least as

high as those required for the base materials.

UG-84(h) Impact Tests of Welding Procedure Quali- fications

UG-84(h)(1) General. For steel vessels of welded

construction, the impact toughness of the welds and heat affected zones of the procedure qualification test plates shall be determined in accordance with (g) above and the following subparagraphs.

UG-84(h)(2) When Required. Welding procedure

impact tests shall be made when required by UCS-67, UHT-82, or UHA-51. For vessels constructed to the rules of Part UCS, the test plate material shall satisfy all of the following requirements relative to the material to be used in production:

(a) be of the same P-Number and Group

Number;

(b) be in the same heat treated condition; and (c) meet the minimum notch toughness require-

ments of UG-84(c)(4) for the thickest material of the range of base material qualified by the procedure (see Fig. UG-84.1).

If impact tests are required for the deposited weld metal, but the base material is exempted from impact tests (as in UHA-51), welding procedure test plates shall be made. The test plate material shall be material of the same P-Number and Group Number used in the vessel. One set of impact specimens shall be taken with the notch approximately centered in the weld metal and perpendicular to the surface; the heat affected zone need not be impact tested.

When the welding procedure employed for production welding is used for fillet welds only, it shall be qualified by a groove weld qualification test. The qualification test plate or pipe material shall meet the requirements of (a), (b), and (c) above when impact testing is a requirement. This welding procedure test qualification is in addition to the requirements of Section IX, QW- 202.2 for P-No. 11 materials.

UG-84(h)(3) Material Over 11_⁄

2in. (38 mm) Thick.

When procedure tests are made on material over 11_⁄ 2 in. (38 mm) in thickness, three sets of impact specimens are required. One set of heat affected zone specimens shall be taken as described in (g)(2) above. Two sets of impact specimens shall be taken from the weld with one set located near (within1_⁄

16 in.) the surface of one side of the material and one set taken as near as practical midway between the surface and the center of thickness of the opposite side as described in (g) above.

UG-84(h)(4) Essential Variables. The additional

essential variables specified in Section IX, QW-250, for impact testing are required.

UG-84(i) Vessel (Production) Impact Test Plates UG-84(i)(1) General. In addition to the require-

ments of (h) above, impact tests of welds and heat affected zones shall be made in accordance with (g) above for each qualified welding procedure used on each vessel or group of vessels as defined in (3) below. The vessel impact test plate shall be from one of the heats of steel used for the vessel or group of vessels. For Category A joints, the test plate shall, where practicable, be welded as an extension to the end of a production joint so that the test plate weldment will represent as nearly as practicable the quality and type of welding in the vessel joint. For Category B joints that are welded using a different welding procedure than used on Category A joints, a test plate shall be welded under the production welding conditions used for the vessel, using the same type of equipment and at the same location and using the same procedures as used for the joint, and it shall be welded concurrently with the production welds or as close to the start of production welding as practicable.

UG-84 PART UG — GENERAL REQUIREMENTS UG-90

UG-84(i)(2) When Required. Vessel (production)

impact test plates shall be made for all joints for which impact tests are required for the welding procedure by UCS-67, UHT-82, or UHA-51 (except where production test plates are specifically exempt by these paragraphs). Test shall be made of the weld metal and /or heat affected zone to the extent required by the procedure test (see UCS-67 and UHA-51).

UG-84(i)(3) Number of Vessel Impact Test Plates Required

(a) For each vessel, one test plate shall be made

for each welding procedure used for joints of Categories A and B, unless the vessel is one of several as defined in (b) or (c) below.

In addition, for Category A and B joints the following requirements shall apply.

(1) If automatic or semiautomatic welding is

performed, a test plate shall be made in each position employed in the vessel welding.

(2) If manual welding is also employed, a

test plate shall be made in the flat position only, except if welding is to be performed in other positions a test plate need be made in the vertical position only (where the major portions of the layers of welds are deposited in the vertical upward direction). The vertically welded test plate will qualify the manual welding in all posi- tions.

(b) For several vessels or parts of vessels,

welded within any 3 month period at one location, the plate thickness of which does not vary by more than 1_⁄

4 in. (6 mm), or 25%, whichever is greater, and of the same specification and grade of material, a test plate shall be made for each 400 ft of joints welded by the same procedure.

(c) For small vessels not exceeding the volume

limitations defined in U-1(j) made from one heat of material requiring impact tests, one welded test joint made from the same heat of material and welded with the same electrode and the same welding procedure may represent one lot of 100 vessels or less, or each heat treatment furnace batch, whichever is smaller.

UG-84(j) Rejection. If the vessel test plate fails to

meet the impact requirements, the welds represented by the plate shall be unacceptable. Reheat treatment and retesting or retesting only are permitted.

UG-85 HEAT TREATMENT

When plate specification heat treatments are not performed by the material manufacturer, they shall be performed by, or be under the control of, the fabricator who shall then place the letter “T” following the letter

75

“G” in the Mill plate marking (see SA-20) to indicate that the heat treatments required by the material speci- fication have been performed. The fabricator shall also document in accordance with UG-93(b) that the speci- fied heat treatment has been performed.

UCS-85, UHT-5(e), and UHT-81 provide require- ments for heat treatment of test specimens.