Hybrid Laser – Arc Welding Applied in Longitudinal Joints for Hydrocarbon Conduction Pipes

2015 ◽  
Vol 1766 ◽  
pp. 45-52
Author(s):  
Raúl J. Fernández Tavitas ◽  
Rocío Saldaña Garcés ◽  
Víctor H. López Cortéz

ABSTRACTIn this paper the effect of hybrid laser arc welding on longitudinal joints for pipes of 1.27cm thick is investigated. For the investigation, an API X70 steel was welded with the HLAW process and then subjected to tensile, bending and micro hardness tests under standards for pipe manufacturing. Images of the weld seams were taken to observe the structure and size of the weld zones. Analysis was made by light microscopy to determine the phases present in the weld zones and to observe if there is a variation of grain size in the weld zones that adversely affects the mechanical properties of the API X70 steel. Results show that the mechanical properties of the joints meet the requirements for their use in pipe manufacturing; one reason is the low thickness of the weld zone that barely affects the original properties of API X70 steel. Also the presence of bainite in the microstructure of weld zones provides resistance to the joints.

2014 ◽  
Vol 496-500 ◽  
pp. 444-447 ◽  
Author(s):  
Zhi Hua Ma ◽  
Dong Gao Chen ◽  
Hong Wei Liu ◽  
Wu Lin Yang

Hybrid laser-Arc welding was to weld 20 mm thickness high nitrogen austenite stainless steel plates. Microstructure, hardness, mechanical properties and fractography of welding joints were researched. The results showed that the microstructure of heat affected zone and weld metal is austenite and δ-ferrite, and the heat-affected zone of welding joints is Narrow, its softening zone is smaller, the hardness is more uniform, the tensile strength of welding joints is 93.8% of the base material, fractured in the weld zone. The tensile fractography are obviously dimple.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4366
Author(s):  
Saqib Anwar ◽  
Ateekh Ur Rehman ◽  
Yusuf Usmani ◽  
Ali M. Al-Samhan

This study evaluated the microstructure, grain size, and mechanical properties of the alloy 800H rotary friction welds in as-welded and post-weld heat-treated conditions. The standards for the alloy 800H not only specify the composition and mechanical properties but also the minimum grain sizes. This is because these alloys are mostly used in creep resisting applications. The dynamic recrystallization of the highly strained and plasticized material during friction welding resulted in the fine grain structure (20 ± 2 µm) in the weld zone. However, a small increase in grain size was observed in the heat-affected zone of the weldment with a slight decrease in hardness compared to the base metal. Post-weld solution heat treatment (PWHT) of the friction weld joints increased the grain size (42 ± 4 µm) in the weld zone. Both as-welded and post-weld solution heat-treated friction weld joints failed in the heat-affected zone during the room temperature tensile testing and showed a lower yield strength and ultimate tensile strength than the base metal. A fracture analysis of the failed tensile samples revealed ductile fracture features. However, in high-temperature tensile testing, post-weld solution heat-treated joints exhibited superior elongation and strength compared to the as-welded joints due to the increase in the grain size of the weld metal. It was demonstrated in this study that the minimum grain size requirement of the alloy 800H friction weld joints could be successfully met by PWHT with improved strength and elongation, especially at high temperatures.


2010 ◽  
Vol 146-147 ◽  
pp. 517-521
Author(s):  
Sheng Hui Xie ◽  
Xie Rong Zeng ◽  
Dong Ju Fu ◽  
Lei Zhao ◽  
Qiang Hu

Cu47.5Zr47.5Al5 bulk metallic glasses (BMGs) were cast from the melt temperature 1143 to 1373 K. The structure, thermal and mechanical properties of the BMGs were investigated by XRD, DSC, HRTEM, dilatometric measurements, micro-hardness tests and uniaxial compression. The results indicate that the microstructure and mechanical performance of BMGs are closely affected by the casting temperature. Proper casting temperature ensures the BMGs with large relaxed excess free volume (REFV) and nano-crystallites, which favor the plastic deformation in Cu47.5Zr47.5Al5 BMGs. Regulating the preparing parameters is an important solution to good plasticity in BMGs.


2012 ◽  
Vol 562-564 ◽  
pp. 573-577
Author(s):  
Xiao Dong Hu ◽  
Yong Zhang ◽  
Jian Tao Lv ◽  
Sen Zhang

The butt weld of Q345R with the thickness of 40mm has been manufactured with the submerged-arc welding (SAW). The mechanical properties of the weld seam have been tested and the metallurgical structures have been analyzed. Conclusions have been obtained as follows: the metallurgical structure of multi-layer butt weld is much more complicated than the monolayer ones; only the last weld layer has the obvious zones of weld zone, heat-affected zone (HAZ) and fusion area; the weld zone and the fusion area will be heat treated with the next layers weld finished; the mechanical property of the multi-layer butt weld is much better than the monolayer weld determined by the corresponding organization.


2019 ◽  
Vol 21 (2) ◽  
pp. 84-96
Author(s):  
Andrey Vorontsov ◽  
◽  
Kseniya Osipovich ◽  
Andrey Chumaevskii ◽  
Veronika Utyaganova ◽  
...  

2012 ◽  
Vol 472-475 ◽  
pp. 2731-2735
Author(s):  
Xiao Dong Hu ◽  
Qing Kun He ◽  
Jian Tao Lv ◽  
Yong Zhang

The butt weld sample with the material of 15CrMoR has been manufactured with the bonding methods of manual electric arc welding (SMAW) and submerged-arc welding (SAW). The relationship between the microstructure and the mechanical properties has been analyzed in this paper, and the conclusions have been obtained as followed: only the last weld layer has the obvious zones of weld zone, heat-affected zone (HAZ) and fusion area for the multi-layer butt weld, the weld zone and the fusion area will be heat-treated by the next layer welding; the hardness along central intersection shows a W-shaped distribution, and the zone with normalizing organization has the lowest hardness and the surface layer has the highest hardness; the mechanical properties of the multi-layer butt weld are much better than the monolayer weld’s.


2012 ◽  
Vol 472-475 ◽  
pp. 2655-2658
Author(s):  
Xiao Dong Hu ◽  
Sen Zhang ◽  
Yong Zhang ◽  
Ya Jiang Li

The microstructure and the mechanical properties of welding joint with the material of TA2 have been studied in this paper with the specimens made with the method of argon-arc welding. The microhardness of the welding joint has been compared with the hardness in the same position of the weld joint after annealing. Conclusions have been obtained as follows: The organizations of the welding joint include base material, recrystallization zone, overheated area, fusion zone and the weld zone; the hardness tendency of the weld joint is depicted as M-shape with the softest point located at the center, and the hardest is located at the overheated zone; the annealing treatment can enhance the weld joint hardness mainly at the center, and the hardness of other zones change little.


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