Abstract:As pipeline design standards require the parameters of mechanical properties, it is crucial to characterize local properties of grith weld. Consequently, the multiscale characterizations based on indentations are performed to study the local properties of these typical zones: weld metal, heat affected zone (HAZ), fusion zone, and base material. The microhardness is measured for entire girth welds of X70 and X80, and the nanohardness is also obtained to analyze the differences in typical zones of girth welds. S… Show more
“…Until now, the welding parameters and heat-treatment techniques have already been mature for P92 steel. [20] However, it is difficult to avoid the welding defects (such as included slag, incomplete fusion, and cracks) during the onsite processing. To guarantee the welding quality, the defected locations should be removed and then welded to repair them.…”
Section: Introductionmentioning
confidence: 99%
“…Until now, the welding parameters and heat‐treatment techniques have already been mature for P92 steel. [ 20 ]…”
The microstructure evolution and mechanical properties of P92 steel welded joint have been systematically investigated relating to the number of tempering cycles. Martensite laths, M23C6 precipitates, and tiny MX phase have been characterized in P92 base metal (BM). Likewise, the heat‐affected zone (HAZ), fusion zone (FZ), and weld metal (WM) show the similar feature of phase composition to the BM. However, δ‐ferrite patches can be found in FZ. With the increasing number of tempering cycles, the area fraction and average size of M23C6 precipitates gradually increase in HAZ and FZ despite that microstructure has little change. Consequently, the hardness, ultimate tensile strength, and yield strength tend to decrease, while the elongation can be improved in some degree. The reduction in solution strengthening, grain refinement strengthening, and precipitation strengthening is responsible for the strength degeneration of P92 steel welded joint with reduplicative tempering.
“…Until now, the welding parameters and heat-treatment techniques have already been mature for P92 steel. [20] However, it is difficult to avoid the welding defects (such as included slag, incomplete fusion, and cracks) during the onsite processing. To guarantee the welding quality, the defected locations should be removed and then welded to repair them.…”
Section: Introductionmentioning
confidence: 99%
“…Until now, the welding parameters and heat‐treatment techniques have already been mature for P92 steel. [ 20 ]…”
The microstructure evolution and mechanical properties of P92 steel welded joint have been systematically investigated relating to the number of tempering cycles. Martensite laths, M23C6 precipitates, and tiny MX phase have been characterized in P92 base metal (BM). Likewise, the heat‐affected zone (HAZ), fusion zone (FZ), and weld metal (WM) show the similar feature of phase composition to the BM. However, δ‐ferrite patches can be found in FZ. With the increasing number of tempering cycles, the area fraction and average size of M23C6 precipitates gradually increase in HAZ and FZ despite that microstructure has little change. Consequently, the hardness, ultimate tensile strength, and yield strength tend to decrease, while the elongation can be improved in some degree. The reduction in solution strengthening, grain refinement strengthening, and precipitation strengthening is responsible for the strength degeneration of P92 steel welded joint with reduplicative tempering.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.