Welding Dissimilar Metals Practical Issues With Forged Steel AISI 8630 Tubular and API X80 Quenched-Tempered Steel Tube
Welding Dissimilar Metals Practical Issues With Forged Steel AISI 8630 Tubular and API X80 Quenched-Tempered Steel Tube
Welding Dissimilar Metals Practical Issues With Forged Steel AISI 8630 Tubular and API X80 Quenched-Tempered Steel Tube
07 March, 2024
Outline
Introduction
Materials
Fabrication Process
Examinations and Tests
Results
Conclusions
2
Introduction
4
Introduction
5
Figure 1: Wellhead Assembly indicative of welding joint
6
Introduction
The case study considered is based on welding sequence and its effect on
solidification cracking, cause and solution; with same material grade,
welding consumables and welding process (assumed not presenting any
challenge)
During the fabrication of a 20 x 31.75mm pipe, forged steel and
quenched/tempered steel, welded using Gas Tungsten Arc Welding (GTAW)
and Submerged Arc Welding process (SAW)
Minimum of 230oC preheat temperature was maintained throughout
welding and with Non-destructive testing (NDT) performed 48 hours after
welding
A crack of 300mm was detected, this crack further propagated to a final
length of 500mm
7
Examinations and Tests
Examined regions:
• Base Material
• Heat Affected Zone (HAZ)
• Weld Metal
• Cracked Section
8
Examinations and Tests
Visual Examination
Magnetic Particle Inspection
Fractographic examination
SEM
EDS
Metallographic examinations
9
Results
10
Results
Figure 4: SEM revealed the presence of numerous more or less aligned cracks
breaking through the external surface of the sample, with depths varying from a
few tens of millimeter to 1.5 mm on the opened portion 12
Results
Figure 6
ELEMENTS DETECTED BY EDS
Spectrum Fe C Mn O Ni Mo Cr Si Ti
Dendrite 85.4 5.7 1.8 2.0 0.9 1.2 0.8 0.9 1.4
Dendrite 89.9 3.7 1.8 1.3 0.9 0.9 0.7 0.5 0.3
Dendrite 87.5 5.8 1.8 1.5 0.9 0.9 0.8 0.6 0.3
Parent metal 93.9 2.4 1.3 0.5 0.5 0.4 0.6 0.3 0.1
Figure 5 Parent metal 93.6 2.6 1.3 0.5 0.7 0.4 0.6 0.3 0.0
Parent metal 89.5 5.6 1.3 1.3 0.7 0.4 0.6 0.3 0.3
13
Results
Figure 7 Figure 8
Cracks are located in the weld metal of the butt welds, more precisely in the lateral capping pass,
on the forged parent material side (AISI 8630) 14
Conclusion
1) Solidification cracking is a damage mechanism that occurs during
the later stage of welding
16
Acknowledgement
• Egina Project
• TotalEnergies
17
Thank you for attending
Merci d’avoir participe
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