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ML00179 - Feb.2022

Hydrides in Titanium Weld

Detail of the end of the rib, with a crack in the fillet weld metal, propagating through the pipe wall.

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Detail of the end of the rib, with a in the metal, propagating through the wall.
M

Material

Unalloyed Titanium
  • ASTM B 862 grade 2
Ds

Description

It was recommended to adopt a welded reinforced rib at the 2" of the drainage system from the 10" main line with the aim of reducing vibration, but the formation of a brittle full of hydrides at the weld, probably associated to lack of proper shielding during field , abbreviated the life and leaded to a (and ) after a very short time in service.

C

Chemistry (% in weight)

2" pipe semiquant

99.6Ti; 0.08V; 0.2Zr; 0.12Cr.

Associated Images
2" drain line from the main 10" line. The leakage occurred at the margin of the weld, a short time after the introduction of the reinforced ribs to reduce vibration.
641
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Field photoDf - General View
Detail of the through wall cracking that caused the leakage in the 2" pipe. The crack was originated in the fillet weld, from the end of the reinforced rib.
72
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Aspect Before AnalysisDf - Fatigue Crack
Low magnification micrography transverse to the fillet weld in the pipe. The pipe base metal is to the bottom of the figure and the weld metal is to the top. The heat affected zone in the middle, shows a coarse grain size structure.
59
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Welded Joint
Low magnification micrography showing the weld metal, full of pores, indicating that the field welding was not properly shileded.
50
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Weld Metal
Granular alpha structure of the pipe base metal.
49
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Alpha
Coarse grains in the heat affected zone.
46
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Heat Affected Zone
Detail of the end of the rib, with a crack in the fillet weld metal, propagating through the pipe wall.
40
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Aspect Before AnalysisDf - Cracking
The through wall cracking was opened by longitudinal cutting of the pipe in two positions, to analyzed the region where the crack was nucleated.
32
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Fracture Surface AspectDf - Fracture
Aspect of the opened crack, showing the flat fracture. The through wall cracking started at the welded region at the end of the rib.
38
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Fracture Surface AspectDf - Fracture
Aspect of the opened crack by scanning electron microscopy, showing the coarser structure in the weld (right side of the figure).
33
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Fractography by SEMDf - Fracture
In the region where the fracture started there are brittle aspects resembling a cleavage micromechanism and several secondary cracks, transverse to the fracture surface, as well as propagation by fatigue (striation).
36
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Fractography by SEMDf - Brittle Cracks
Fractography showing brittle secondaryy cracks in the region where the cracking was originated.
34
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Fractography by SEMDf - Secondary Cracks
Micrography of the weld metal at the fillet weld where the cracking started, showing several brittle microcracks that corresponds to the regions where the fractography showed secondary crackis.
35
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Weld Metal
Micrographic detail of the weld metal brittle microcracks, in regions with hydrides formation.
32
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Weld Metal
Brittle crack in the surface of the welded joint, at the heat affected zone close to the fusion line.
30
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Heat Affected Zone
Micrographic detail of the brittle crack in the surface of the welded joint, at the heat affected zone close to the fusion line.
30
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Heat Affected Zone
Fractography showing propagation by fatigue. Striation.
26
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Fractography by SEMDf - Fatigue Striation
Micrographic aspect of the weld metal presenting brittle detached parts in the starting point of the fracture, in the weld metal, and several fatigue cracks propagating from the stress concentration raisers.
23
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Fatigue Crack
Micrographic detail of transgranular propagation of the cracking by fatigue.
34
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Fatigue Crack
Hydrides in Titanium Weld
1
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Aspect Before AnalysisDf - General View
Hydrides in Titanium Weld
2
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Aspect by NDTDf - Crack
Hydrides in Titanium Weld
3
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Fracture Surface AspectDf - Fracture
Hydrides in Titanium Weld
1
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Micrography by OMDf - Welded Joint
Hydrides in Titanium Weld
2
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Micrography by OMDf - Weld Metal
Hydrides in Titanium Weld
2
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Micrography by OMDf - Heat Affected Zone
Hydrides in Titanium Weld
4
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Micrography by OMDf - Heat Affected Zone
Hydrides in Titanium Weld
1
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Micrography by OMDf - Hydride Formation
Hydrides in Titanium Weld
2
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Micrography by OMDf - Heat Affected Zone