Effect of Structural State of Metal in Weld Fusion Zone of Large-Diameter pipes on Fracture Mechanism and Results of Crack-Resistance (CTOD) Tests

Metallurgist ◽  
2020 ◽  
Vol 63 (9-10) ◽  
pp. 1054-1070
Author(s):  
V. Ya. Velikodnev ◽  
P. P. Stepanov ◽  
S. Yu. Nastich ◽  
L. I. Éfron ◽  
I. P. Shabalov ◽  
...  
Keyword(s):  
Crack Resistance ◽  
Fusion Zone ◽  
Fracture Mechanism ◽  
Structural State ◽  
Large Diameter ◽  
Weld Fusion Zone ◽  
Large Diameter Pipes

scholarly journals Microstructural Characterization of Laser Weld of Hot-Stamped Al-Si Coated 22MnB5 and Modification of Weld Properties by Hybrid Welding

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3943
Author(s):  
Hana Šebestová ◽  
Petr Horník ◽  
Šárka Mikmeková ◽  
Libor Mrňa ◽  
Pavel Doležal ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Fusion Zone ◽  
Microstructural Characterization ◽  
Tensile Tests ◽  
Laser Weld ◽  
Martensitic Microstructure ◽  
Laser Welds ◽  
Weld Properties ◽  
Weld Fusion Zone

The presence of Al-Si coating on 22MnB5 leads to the formation of large ferritic bands in the dominantly martensitic microstructure of butt laser welds. Rapid cooling of laser weld metal is responsible for insufficient diffusion of coating elements into the steel and incomplete homogenization of weld fusion zone. The Al-rich regions promote the formation of ferritic solid solution. Soft ferritic bands cause weld joint weakening. Laser welds reached only 64% of base metal's ultimate tensile strength, and they always fractured in the fusion zone during the tensile tests. We implemented hybrid laser-TIG welding technology to reduce weld cooling rate by the addition of heat of the arc. The effect of arc current on weld microstructure and mechanical properties was investigated. Thanks to the slower cooling, the large ferritic bands were eliminated. The hybrid welds reached greater ultimate tensile strength compared to laser welds. The location of the fracture moved from the fusion zone to a tempered heat-affected zone characterized by a drop in microhardness. The minimum of microhardness was independent of heat input in this region.

Load-carrying ability of large-diameter pipes

1978 ◽  
Vol 10 (1) ◽  
pp. 29-34 ◽  
Author(s):  
V. V. Chelyshev ◽  
V. G. Burdukovskii ◽  
B. N. Gubashov ◽  
V. V. Kirichenko
Keyword(s):  
Large Diameter ◽  
Load Carrying ◽  
Large Diameter Pipes

Factory-applied anticorrosive insulation for large-diameter pipes

Metallurgist ◽  
1987 ◽  
Vol 31 (10) ◽  
pp. 320-321
Author(s):  
V. M. Ryabov ◽  
L. A. Usova
Keyword(s):  
Large Diameter ◽  
Large Diameter Pipes

Numerical Simulation of UOE Pipe Process and its Effect on Pipe Mechanical Behavior in Deep-Water Applications

2015 ◽  
Author(s):  
Giannoula Chatzopoulou ◽  
Spyros A. Karamanos ◽  
George E. Varelis
Keyword(s):  
Deep Water ◽  
Manufacturing Process ◽  
Large Diameter ◽  
Structural Response ◽  
Structural Instability ◽  
External Pressure ◽  
Line Pipe ◽  
Simulation Tools ◽  
Large Diameter Pipes ◽  
Pipe Manufacturing

Large-diameter thick-walled steel pipes during their installation in deep-water are subjected to a combination of loading in terms of external pressure, bending and axial tension, which may trigger structural instability due to excessive pipe ovalization with catastrophic effects. In the present study, the UOE pipe manufacturing process, commonly adopted for producing large-diameter pipes of significant thickness, is considered. The study examines the effect of UOE line pipe manufacturing process on the structural response and resistance of offshore pipes during the installation process using nonlinear finite element simulation tools.

High end inspection by filmless radiography on LSAW large diameter pipes

2010 ◽  
Vol 43 (3) ◽  
pp. 206-209 ◽  
Author(s):  
Thomas Kersting ◽  
Norbert Schönartz ◽  
Ludwig Oesterlein ◽  
Andreas Liessem
Keyword(s):  
Large Diameter ◽  
Large Diameter Pipes
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