Skip to main content

Table 12 Test results of weld crack position

From: Failure analysis of weld cracking of gas gathering pipeline in dewatering station

Item\number

Low magnification

High magnification

1#

The crack extended from the inner wall fusion zone and penetrated the entire wall thickness. The maximum crack width is about 0.4mm (Figs. 17, 18 and 19).

No welding defects such as inclusions, holes, or unfused metal were found around the crack, and no abnormal microstructure was found around the crack. There were many micro cracks along the crystal (Figs. 20, 21 and 22).

2#

The crack extended from the fusion zone of the inner wall, and there are extended cracks in the heat affected zone (Figs. 23 and 24).

No welding defects such as inclusions, holes, or unfused mental were found around the crack, and no abnormal microstructure was found around the crack. There were many microcracks along the crystal (Figs. 25 and 26).

3#

The crack extended from the fusion zone of the inner wall and is branched (Figs. 27 and 28).

No welding defects such as inclusions, holes, and unfused mental were found around the crack, and no abnormal microstructure was found around the crack. There were many microcracks along the crystal (Figs. 29, 30 and 31).