In this research paper, the failure pressure predictions were obtained for a pipeline section by analyzing a combined corrosion defects, which joins together a general corrosion and a pitting corrosion defects. Well-known conventional mathematical methods were used in this study to predict the failure pressure of corroded steel pipelines, such as: B31G, RSTRENG-1, Shell-92, DNV, PCORR, and Fitnet FFS. The equations reported for corrosion defects with more complex characteristics developed by Choi et al., and Cronin et al. were also used. Furthermore, Finite Element (FEM) is one of the most employed nonlinear methods because of its good response of pipeline failure prediction under the corrosion mechanism. So, FEM methodology results the least conservative in comparison with the others mathematical models, according to the literature, for this reason it was used to compare the standard deviation  of the methods. Failure pressure predictions determined that the most conservative methods were: Shell-92, Fitnet FFS, Choi's method, B31G, RSTRENG-1, Cronin´s method, PCORR and DNV, in that order.

This study presents K IC data obtained from K IC -CVN correlations from Charpy CVN values. For this study, T-welded connections were manufactured from ASTM A36 and E6013 electrodes in dry conditions. Then, a rectangular grinding at the weld toe was carried out and filled with wet welding. Charpy specimens were extracted to obtain CVN values. An exhaustive search through the literature of several authors was performed to collect experimental CVN data about wet welding being applied to A36 steel for comparison with CVN data obtained in this study. By using Charpy impact energy (CVN), K IC values could be predicted by K IC -CVN correlations. In addition, correlations were presented to obtain K IC values in the lower shelf, transition temperature zones and different zones for the energy-temperature curve of A36 steel. Of these correlations, Barsom's equation was adopted, because he applied the stress yield (σ YS ) of the material and it can be applied in all zones for the energy-temperature curve. The results revealed that CVN values are proportionate to K IC , this data decreases as water depth increases. This took place because several discontinuities, such as, porosity, slag inclusion, non-metallic inclusion, cracking and microstructures are present in the wet welding.