A Novel Approach to Weld Flow Analysis of Electric Resistance-Welded (ERW) Tubes: Significance and Implications

Carbon pipes manufactured using the techniques of electric resistance welding (ERW) and high-frequency induction welding (HFIW) processes offer considerable savings in cost to the potential end user when compared one-on-one with both the seamless welded pipes and the submerged arc-welded (SAW) pipes. Over the years, this sort of pipes was not fully trusted for the purpose of selection and use in applications in the industries spanning oil and natural gas. This is essentially because of the occurrence of sudden and catastrophic failure while in service. This necessitated the need for an incorporation of important quality checks into the process with the prime objective of avoiding catastrophic failure during service while concurrently ensuring a healthy synergism of trust and reliability in the industries spanning oil, gasoline, and automobiles. In this paper, the significance and need for this research study, resultant impact, and far-reaching applications are presented and adequately discussed. This paper highlights all the intricacies specific to an analysis of the weld flow lines that are formed during electric resistance welding (ERW) process and its concomitant influence on mechanical properties and overall mechanical performance. To have sound-welded electric resistance-welded (ERW) tubes, there are a couple of parameters, which are both important and need to be taken into consideration. An important parameter is the optimal compressive force that is required to be applied during the manufacturing process that is used for the welding rolls to undergo or experience deformation. This parameter is assessed from the pattern of weld flow lines that are formed. Once the product is ready, a careful and comprehensive examination of the weld flow lines was carried out at the junction of the heat-affected zone (HAZ) of the electric resistance-welded (ERW) tubes. Results and details of the examination will help the manufacturer to meticulously assess overall quality of the weld on the electric resistance-welded (ERW) tubes by a careful and systematic analysis of both the weld flow lines pattern and angle of bend in the heat-affected zone (HAZ). This essentially involves metallographic sample preparation followed by precision etching and microscopic examination with the prime purpose of observing the weld flow lines in the heat-affected zone (HAZ). The weld flow lines and pattern were analyzed using an optical microscope at low magnifications.