Defects and residual stresses effect on the functional performance of a 106 pipes after the welding process

Abstract

Producing soundness weldments is the main goal to avoid catastrophic failures that occur in oil refineries, where the interaction of internal defects and residual stress with the working conditions leads to human and financial losses. AISI 1020- A106 carbon steel pipes that are used for oil products transmitted inside oil refineries have a 55 mm inner diameter with a 5 mm thickness and had been welded with shielded metal arc welding (SMAW) for the first samples group, while the second group was welded using gas tungsten arc welding (GTAW) process. For surface defects detection the liquid penetration method was used, while for internal defects radiography method was used, and for residual stresses X-ray diffraction was used. The results showed that the first group of samples contained different types of internal defects with compressive residual stresses, while the second group was nearly clear of internal defects with tensile residual stresses.

Keywords:

• Welding process
• defects
• residual stress
• phase transformation

Acknowledgments

The authors would like to acknowledge the pipes and vessel department in the EL-Dora refinery, which provides carbon steel pipes, and the engineering testing department for radiography testing and support. We acknowledge the General Company for Heavy Engineering Equipment for their support and the pipe welding process used in this study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical statement

This manuscript is our original work, which has not been previously published elsewhere and is not currently being considered for publication elsewhere. This study reflects our research and analysis truthfully and completely. The results were appropriately placed in the context of prior and existing research. All the sources used were properly disclosed (correct citations). We have been personally and actively involved in substantial work leading to this paper, and we will take public responsibility for its content.

Statements and declarations

Statements - Data available as supplementary information.

The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this study.