Welded Joint

3 cases · 7 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Raw Material Microstructure: Ferritic pearlitic clear all

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Identification of the regions of metallographies of the base metal, heat affected zone (HAZ) and weld metal. Locations in the root, in the center of the thickness and close to the tube OD (external surface).
118
VIEW
ML00177 / Dec.2021
Cr-Mo Seam Welded Tube
M - CrMo SteelP - Longitudinally Seam WeldedAp - Fired HeaterCd - Not according to spec
Cm - NItal Etched MacroDf - Welded Joint
Macrography of a section longitudinal to the pipe and transverse to the weld. The thickness of the pipe is 12,7 mm (1/2") and it was welded in 6 passes, the root pass, one fill pass and four cap passes.
855
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - NItal Etched MacroDf - Welded Joint
Micrography of the seam welded joint, autogenous. The localized dissolution occurrs exactly at the weld metal that presents a bainitic structure and Vickers (100g) microhardness values about 230HV, compared to the heat affected zone presenting average of 202 HV and the base metal presenting average of 180HV.
59
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by SEMDf - Welded Joint

More from these cases

ML00153 — X52 in a Tubular StructureM - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Schematic drawing of the API 5L X52 pipe, butt welded to another pipe, showing the 4 cap passes. The pipe is nominal diameter 8" and thickness 1/2". The qualification of the WPS was conducted according to the structural code, with toughness requirements (Charpy V at 0°C), with 4 lateral bending tests, all approved, and 2 welded joint tensile tests, one with ruptured in the base metal and the other ruptured in the weld metal, both presenting strenght level higher than the minimum specified. The pipe was tensile tested.
95
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - Identification drawingDf - Welded Joint
Micrography of the weded joint at the cap pass fusion line. The columnar structure of the weld metal is to the top of the figure; and it is possible to see the coarse grains at the heat affected zone. Both columnar structure and coarse grains are related to the previous austenite grain boundaries. From the fusion line to the base metal (in the bottom of the figure) the grain sizes are refined.
86
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - Nital Etched Micrography by OMDf - Welded Joint
Micrography of the weld metal in the region of the cap pass that was not reheated, last bead, presenting previous austenite columnar grains, coarse.
69
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - Nital Etched Micrography by OMDf - Welded Joint
Micrography of the weld metal in the root, reheated by the fill pass, presenting a refined ferritic structure.
49
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - Nital Etched Micrography by OMDf - Welded Joint