Effect of Chloride on Offshore Structure Welding Procedure

The objective of this research was to determine the effect of chloride to the welded
ASTM A516 Grade 70 materials. The used of proper welding procedure may
eliminate the probability of crack occurrences, but there were still cracking happen
in some offshore welding. That was because the failures may occur hours or days
after the welding work completed. The scope of the study was on ASTM A516
Grade 70 steels welded using WPS FSP-HLE-17-49 procedure and exposed under
salt environment according to ASTM G41-90 at 35°C for period of 1 to 5 days. Non
Destructive Examination such dye penetrant and magnetic particle testing were used
to investigate the initial conditions of specimen and the conditions after exposing the
materials under the simulated offshore environment. Metallographic examinations of
the specimen were crucial in this study. The study had shown that the welded
structure using the WPS produced complete welds with no visible surface crack. The
hardness of the weld and the HAZ was 213(HV10) and 224 (HV10) respectively.
There were found to be well below critical hardness value i.e. 300 (HV10) for weld
metal and 248 (HV10) for HAZ, as according to PTS 20.112. There were no surface
cracks found throughout the duration of the study. The study concludes that if the
welding was done in strict compliance with the code and standard, high weld
integrity would be produced.