Class B Welds

8.1 Application

The requirements of this section apply to Class B welds. Class B underwater welds are intended for less critical applications where lower ductility, moderate porosity and other larger discontinuities can be tolerated. This class of weld shall meet the requirements of this specification for Class B welds, and shall satisfy the Customer's requirements for a particular application.

8.1.1 Welding procedure specifications for Class B welds shall be qualified in accordance with the general requirements of section 5, Parts I and II, and the specific requirements of Part I of this section.

8.1.2 All welders, including tack welders, making Class B welds shall be qualified prior to production welding in accordance with the general requirements of section 5, Part I and III, and the specific requirements of Part II of this section.

8.1.3 Minimum examination requirements for all Class B production welds and acceptance criteria for all inspection and examination of Class B welds, including that performed during procedure and performance qualification, are outlined in Part III of this section.

Parti Procedure Qualification

8.2 Testing Requirements

The number and type of test specimens required for procedure qualification to test the first position and additional positions for Class B welds are summarized in Table 8.1.

8.3 Groove Welds

8.3.1 Test Specimens. Test specimens for Class B welds shall be located in accordance with Figures 8.1 or 8.2.

83.2 Test Results. Procedure Qualification test results for Class B groove welds shall meet the following requirements:

8.3.2.1 Visual Examination. The weld shall meet the visual acceptance criteria of 8.9.

83.2.2 Radiographic Examination. The weld shall meet the radiographic acceptance criteria of 8.10.

83.23 Reduced-Section Tension Tests. The tensile strength shall equal or exceed the specified minimum tensile strength of the base metal for each sample.

83.2.4 Bend Tests. The bending fixture shall conform to Figure 5.12 of section 5, Part II. Maximum bend radius for testing shall be 6T unless a smaller radius is specified by the customer. Four samples shall be tested, and none shall reveal tears or other defects exceeding 3 mm (1/8 in.) in the weld metal or fusion zone after the bending. Tears which originate at the corner of the specimen and are less than 6 mm (1/4 in.) long shall not be cause for rejection unless they are associated with a defect.

83.2.5 Macroetch. Macroetch test specimens shall contain no cracks at 5X magnification and shall meet the requirements of 8.10. Microhardness measurements shall not exceed 375 HV10 (see 5.11.6) unless otherwise specified by the Customer.

83.2.6 Charpy Impact Test. The average and minimum Charpy energy values shall satisfy the requirements of Table 8.2, unless other requirements are specified by the customer.

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