Welding Procedure Qualification

Welding procedures shall be qualified in accordance with Code Section X and Code Division 2 requirements and the following:

1. Base metal for welding procedure qualification tests shall be made from the same ASME Code material specification (same P-number and Group number) and nominal chemistry as specified for the vessel; but either plate or forging may be used.

2. Welding electrodes, wire and flux combination shall be of the same type and brand as those to be used in production welding.

3. Charpy V-notch impact testing shall be performed on the weld metal and heat affected zone (HAZ) for each welding procedure as specified for the weld metal in Section 7.2.

4. Step-cooling tests shall be performed on the weld metal and HAZ for each welding procedure.

5. Previously qualified weld procedure specifications (WPS) with step-cooling tests may be accepted by Purchaser based on WPS compliance with item 1 above.

For each welding procedure, three Vickers hardness traverses of the weld joint shall be made on a weld sample in the minimum PWHT condition.

a. Hardness traverses shall be made 0.04 inches to 0.08 (1 mm to 2 mm) below both surfaces and at ½ T, where T is the material thickness.

b. Each traverse shall include 10 hardness readings for a total of 30 hardness readings per weld sample.

c. The hardness shall not exceed 235 HV10 for conventional steels and 248 HV10 for advanced steels.

6. Three tensile tests, transverse to the weld, shall be performed for each welding procedure.

a. Two tests shall be performed at ambient temperature.

b. Another tensile test shall be performed at design temperature and shall meet the elevated temperature properties specified for the base metal in Section 6.6

Exercise 5. Agree or disagree. Correct the false statements.

1. Welding electrodes, wire and flux combination do not have to be of the same type and brand as those to be used in production welding.

2. Vickers hardness traverses of the weld joint shall be made on a weld sample in the maximum PWHT condition.

3. Three tensile tests shall be performed at ambient temperature.

Exercise 6. Answer the questions:

1. What shall be the nominal chemistry of the base metal?

2. What shall be the type of welding consumables?

3. What kind of testing shall be performed on the weld joint?

4. How shall Vickers traverses be made?

5. At what temperatures shall the testing be made?

6. What kind of welding consumables do you know?

Exercise 7. Imagine that an English-speaking Code inspector has come to your factory to check the quality of the placed order. Explain to him what kind of weld testing procedures you use.

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