Acid corrosion at welds - Corrosion defects

Acid corrosion at welds - Corrosion defects

Figure 1: Acid corrosion at welds.

Table 1: Service data.

Defect name: Acid corrosion
Record No.: 2478
Type of defect (Internal/Surface): Surface
Defect classification: Corrosion defects
Steel name: Steel
Steel composition in weight %: No data.
Note: Low-pH corrosion during acid cleaning.
Figure 1 illustrate attack of the internal surfaces of wall tubes opposite external circumferential welds. Cross-sectional profiles of the internal surface in these attacked zones revealed undercutting and jaggedness. Residual stresses remaining from the weld make these sites subject to preferential corrosion when exposed to strong acid.
Reference: Not shown in this demonstration version.