CEMP-E
TI 809-26
1 March 2000
testing (UT), the visual inspection criteria is applicable, plus the requirements of AWS D1.1 Section 6.13.
For radiographic testing (RT), the visual inspection criteria is applicable, plus the requirements of AWS
D1.1 Section 6.12.
d. Alternate Acceptance Criteria. The Engineer may base alternate weld quality acceptance criteria on
experience, experimental results, structural analysis, or fracture mechanics analysis considering material
properties and behavior, service and fracture loads and strengths, and environmental factors. Sources of
information to assist in the development of alternate acceptance criteria are provided in Appendix B,
Bibliography.
7. REPAIRS TO BASE METAL AND WELDS.
a. Mill Defects. ASTM A6 Section 9, requires only visual inspection by the mill of the completed
product for defects in workmanship. Subsurface inspection for laminations and other defects, such as
straight-beam ultrasonic testing, would be performed only when specified in the mill order, at extra cost.
The mill is permitted to perform removal and repairs to the surface using various means such as grinding
and welding, to limits specified in ASTM A6 Section 9. During fabrication, should unacceptable internal
discontinuities be discovered in the steel, the steel may be considered rejectable. The size or type of
internal discontinuity considered rejectable is not defined by specification.
b. Laminations. When internal laminations in the steel are discovered during fabrication, AWS D1.1
Section 5.15.1, provides procedures for the investigation and repair of the exposed laminations. All
exposed laminations must be explored for depth. Shallow laminations need not be repaired, but longer
and deeper laminations will need either removal by grinding or welding to close the lamination prior to
welding the joint. Laminations at welded joints may serve as sources of porosity and as crack initiation
points.
c. Weld Discontinuities. For welds with unacceptable convexity, excessive reinforcement, or overlap,
the weld should have the excess weld metal removed. This is typically done by grinding, but may be
done by gouging. For undersized welds, including craters, the weld should be filled to the required size.
Some craters may be acceptable if outside the required effective length of weld. For excessive undercut,
the undercut portion should be filled using an approved repair procedure. For cracks, lack of fusion, and
excessive porosity, the unacceptable portion must be completely removed and replaced. Additional
caution should be used when repairing cracks. The end of the crack should be located using PT or MT,
then crack removal should begin approximately 50 mm (2 in.) from the end of the crack and work toward
the center of the crack. Starting within the crack may cause the crack to grow during removal. See AWS
D1.1 Section 5.26.1. Should it be necessary to cut the materials apart, the Engineer must be notified.
d. Root Opening Corrections. Root openings that are too narrow must be increased in width to the
required root opening. Narrow root openings contribute to trapped slag, poor penetration and lack of
fusion near the root. Repairs for narrow root openings may be done by grinding, chipping, air carbon arc
gouging, if refitting the parts is not feasible. Root openings that are too wide are significant in that they
increase the weld volume, increasing distortion and increasing the risk of lamellar tearing in T-joints, as
well as increasing cost. A root pass placed across a wide root opening may develop shrinkage cracks in
the HAZ or in the throat of the weld. Repair of wide root openings entails facing the groove with weld
metal until the required root opening is achieved. Such a repair does not reduce volume or cost, but
controls distortion and through-thickness strains in T-joints. An alternative to repair of this type would be
to use split-layer techniques for the root pass, and subsequently control bead placement to minimize
shrinkage and distortion effects.
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