Weld defects location

Welding Defects Visual, radiographic and/or ultrasonic Indications. Any welded joints. Basic welding problem laminated steel can cause trouble. Electrode manipulation. Control of welding speeds, procedures, careful inspection and nondestructive testing to locate defects for cutting out or repair. 

AUQUR 4.2 revealed a number of small-size defects with the height of about 2 mm did not detected by manual inspection. These flaws were located near the boundaries of cut-off zone of repaired welds and likely had originated after near-boundary passes of repair welding [3]. 

Weld inspection duties of personnel responsible for judging the quahty of welding with regard to specifications have been treated (15). Some of these duties involve the visual inspection of welds to determine if they are of the proper size, location, and type and are free of defects. Specifications of materials used must be checked, as must equipment and procedures. 

Figure 14.4 Tubercle capping a pit located in a weld-seam defect.

General description. Incomplete penetration describes the condition in which the weld fails to reach the bottom of the weld joint, resulting in a notch located at the root of the weld (Fig. 15.12). This critical defect can substantially reduce the intrinsic mechanical strength of the joint and can combine with environmental factors to produce corrosion fatigue (Chap. 10), stress-corrosion cracking (Chap. 9), or crevice corrosion (Chap. 2). 

Locations. Locations of defects of this type are essentially unpredictable but can occur wherever laminated metal is welded. 

Limited data show that both welding practice and location of defects can dictate the hydrogen embrittlement snsceptibility of a weld. A study on microalloyed steel API 5L Grade X60 examined weld joints that were fabricated using either one or two weld passes." Fractnre mechanics specimens were extracted from the base metal, fusion zone, and heat-affected zone and tested in 7-MPa hydrogen gas. Results showed that Kj values measured in the weld fnsion zones were similar to valnes in the base metal, i.e., Rju was approximately 100 MPaVm in each region. In contrast, the heat-affected zones were more susceptible to hydrogen embrittlement, and Rju was difficult to measure. The heat-affected zone in the two-pass weld was most susceptible. 

Control of welding speeds, procedures, careful inspection and nondestructive testing to locate defects for cutting out or repair. 

This technique is mostly applied for the detection of spatial defects in anodic or cathodic protection systems on complex structures or components. Thus, attempts have been made to detect single locations in components that are usually passive but which may undergo some form of active corrosion in particular areas such as welds, crevices, pits, cracks, etc. 

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