ARTICLE KT-2IMPACT TESTING FOR WELDED VESSELS

KT-200 IMPACT TESTS

(a) For vessels of welded construction, the toughnessof welds and heat-affected zones of procedure qualifica-tion test plates and vessel production test plates shallbe determined as required in this Article.

(b) Test plates shall be subjected to heat treatment,including cooling rates and aggregate time at tempera-ture or temperatures, essentially the same as establishedby the Manufacturer for use in actual manufacture. Thetotal time at temperature shall be at least 80% of thetotal time at temperature during actual heat treatmentof the product and may be performed in a single cycle.

(c) The test temperature for welds and heat-affectedzones shall not be higher than for the base materials.

(d) Impact values shall be at least as high as thoserequired for the base materials [see Table KM-234.2(a)].

KT-210 LOCATION AND ORIENTATIONOF SPECIMENS

All weld impact specimens for both weld proceduresand production tests shall comply with the followingrequirements.

(a) One set of weld metal impact specimens shallbe taken across the weld with the notch in the weldmetal. Each specimen shall be oriented so that thenotch is normal to the surface of the material, and oneface of the specimen shall be within1⁄16 in. (1.6 mm)of the surface of the material. When tests are madeon material over 11⁄2 in. (38 mm) in thickness, twosets of impact specimens shall be taken from the weld,with one set located within1⁄16 in. (1.6 mm) of thesurface of one side of the material, and one set takenas near as practical midway between the surface andthe center of thickness of the opposite side as describedabove.

(b) One set of heat-affected zone impact specimensshall be taken across the weld and of sufficient lengthto locate, after etching, the notch in the affected zone.The notch shall be cut approximately normal to thematerial surface in such a manner as to include as

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much heat-affected zone material as possible in theresulting fracture.

KT-220 IMPACT TESTS FOR WELDINGPROCEDURE QUALIFICATIONS

Impact tests shall be required on weld and heat-affected zones for all welding procedure qualifications.

KT-221 Variables for Impact TestingProcedures

See Section IX, QW-250.

KT-222 Thickness Qualified When LowerCritical Temperature Is Exceeded

For test plates or pipe receiving a postweld heattreatment in which the lower critical temperature isexceeded, the maximum thickness qualified is the thick-ness of the test plate or pipe.

KT-230 IMPACT TEST OF PRODUCTIONTEST PLATES

Impact tests of welds and heat-affected zones shallbe made in accordance with KT-210 for each qualifiedwelding procedure used on each vessel. Test platesshall be taken from one of the heats of material usedfor the vessel production for Category A and B weldjoints and shall be welded as an extension to the endof the production weld joint where practical, weldedimmediately prior to the start of production, or weldedconcurrently with the production weld, utilizing weldingmaterials and procedures which are to be used on theproduction joint. If test plates are welded concurrentlywith the production weld, the welding equipment shallbe of the same type as used for production and thelocation of the test plate welding shall be immediatelyadjacent to the production welding. In addition, thefollowing requirements shall apply.

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KT-230 PART KT — TESTING REQUIREMENTS KT-240

(a) If automatic or semiautomatic welding is per-formed, a test plate shall be made in each positionemployed in the vessel welding.

(b) If manual welding is to be employed in thehorizontal flat position only, a test plate shall be madein the flat position. A vertical test plate with the majorportions of the layers of welds deposited in the verticalupward position shall be used to qualify the weldingprocedure when welds are made in any other position.The vertically welded test plate will qualify the manualwelding in all positions.

(c) Impact tests shall be valid only if the thicknessof the vessel test plate meets the requirements of QW-

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451.1 (including Notes) of Section IX, except that, ifthe thickness is less than5⁄8 in. (16 mm), the thicknessof the test material shall be the minimum thicknessqualified.

KT-240 BASIS FOR REJECTION

If the vessel test plate fails to meet the impactrequirements, the welds represented by the test plateshall be unacceptable. Reheat treatment in accordancewith Part KM and retesting are permitted.

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