Microstructure and Mechanical Properties of Welding Joints of High Nitrogen Steel by Hybrid Laser-Arc Welding

2014 ◽  
Vol 496-500 ◽  
pp. 444-447 ◽  
Author(s):  
Zhi Hua Ma ◽  
Dong Gao Chen ◽  
Hong Wei Liu ◽  
Wu Lin Yang
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Weld Zone ◽  
Base Material ◽  
Steel Plates ◽  
High Nitrogen ◽  
Hybrid Laser Arc Welding ◽  
Δ Ferrite ◽  
Welding Joints

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.

Measurement of Weld Mechanical Properties Using an Instrumented Indentation Technique

2017 ◽  
Vol 754 ◽  
pp. 383-386
Author(s):  
Kee Nam Song
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Weld Zone ◽  
Base Material ◽  
Metal Structure ◽  
Instrumented Indentation ◽  
Welded Structures ◽  
Indentation Technique ◽  
Lower Confidence ◽  
Welded Structure

Different microstructures in the weld zone of a metal structure including a fusion zone and a heat affected zone, are formed as compared to the base material. Consequently, the mechanical properties in the weld zone are different from those in the base material to a certain degree owing to different microstructures and residual welding stresses. When a welded structure is loaded, the mechanical behavior of the welded structure might be different from the case of a structure with homogeneous mechanical properties. It is known that obtaining the mechanical properties in the weld is generally difficult owing to the narrow regions of the weld and interfaces. As an alternative way to obtain the weld mechanical properties, the weld mechanical properties of Alloy800HT, SUS316L, and Alloy617, were recently measured using an instrumented indentation technique, and the representative weld mechanical properties of these materials were estimated with a 95% lower confidence level for later structural analyses of the welded structures.

Study on the Microstructure and the Mechanical Properties of TA2

2012 ◽  
Vol 472-475 ◽  
pp. 2655-2658
Author(s):  
Xiao Dong Hu ◽  
Sen Zhang ◽  
Yong Zhang ◽  
Ya Jiang Li
Keyword(s):  
Mechanical Properties ◽  
Fusion Zone ◽  
Weld Joint ◽  
Arc Welding ◽  
Weld Zone ◽  
Base Material ◽  
Annealing Treatment ◽  
Welding Joint

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.

Study on the Microstructure and the Mechanical Properties of Zr R60702

2012 ◽  
Vol 510 ◽  
pp. 679-682 ◽  
Author(s):  
Xiao Dong Hu ◽  
Sen Zhang ◽  
Yong Zhang ◽  
Ya Jiang Li
Keyword(s):  
Mechanical Properties ◽  
Fusion Zone ◽  
Weld Joint ◽  
Arc Welding ◽  
Weld Zone ◽  
Base Material ◽  
Annealing Treatment ◽  
Welding Joint

The microstructure and the mechanical properties of welding joint with the material of R60702 have been studied in this paper with the specimens made with the method of argon-arc welding, and the according mechanical properties of the weld joint have been compared with the annealed microstructure at the temperature of 600.Conclusions have been obtained as follows: The organizations of the welding joint include base material, normalizing zone, overheated area, fusion zone and the weld zone; the hardness tendency of the weld joint is depicted as W-shape with the hardest point located at the center, and the softest points is located at the normalizing zone; the annealing treatment can improve the ductility and soften the weld joint mainly at the center.

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
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Arc Welding ◽  
Weld Zone ◽  
Micro Hardness ◽  
Hybrid Laser Arc Welding ◽  
Hardness Tests ◽  
Longitudinal Joints ◽  
Weld Seams ◽  
Pipe Manufacturing

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.

Mechanical Properties of Arc Welding Heat-Affected Zone of High Nitrogen Steel

2007 ◽  
Vol 14 (5) ◽  
pp. 263-267 ◽  
Author(s):  
Wan-sheng DU ◽  
Lin ZHAO ◽  
Zhi-ling TIAN ◽  
Yun PENG ◽  
Liang-hong XU
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
High Nitrogen Steel ◽  
High Nitrogen ◽  
Nitrogen Steel

Effect of Laser Welding on the Mechanical Properties AISI 1018 Steel

MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4031-4039 ◽  
Author(s):  
M. A. Carrizalez-Vazquez ◽  
M. Alvarez-Vera ◽  
A. Hernández-Rodríguez ◽  
J. M. Orona-Hinojos ◽  
Gabriel Sandoval-Vázquez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laser Welding ◽  
Fusion Zone ◽  
Heat Affected Zone ◽  
Welding Speed ◽  
Laser Power ◽  
Steel Plates ◽  
Welding Joints ◽  
Welding Processes

AbstractLaser welding processes offer significant advantages such as high welding speed, narrow heat affected zone and quality of the welding joint. In this study, the process parameters of laser power and welding speed were modified for AISI 1018 steel plates of 8 mm thickness and compared using finite element method. The results of cross-section microstructure, heat affected zone and fusion zone were characterized. The grain refinement was affected as the parameters were modified. Tensile and microhardness tests were performed to determine the mechanical properties of the welding joints. Microhardness increased in fusion zone and decreased in heat affected zone. Tensile test showed ductile fracture in heat affected zone of the welding joints. The simulated profiles were compared with the experimental observations showing a reasonable agreement.

scholarly journals Experimental Study on Laser-MIG Hybrid Welding of Thick High-Mn Steel Plate for Cryogenic Tank Production

2021 ◽  
Vol 9 (6) ◽  
pp. 604
Author(s):  
Du-Song Kim ◽  
Hee-Keun Lee ◽  
Woo-Jae Seong ◽  
Kwang-Hyeon Lee ◽  
Hee-Seon Bang
Keyword(s):  
Low Temperature ◽  
Yield Strength ◽  
Steel Plate ◽  
Weld Zone ◽  
Base Material ◽  
Hardness Test ◽  
Steel Plates ◽  
Hybrid Welding ◽  
Temperature Impact ◽  
Mn Steel

The International Maritime Organization has recently updated the ship emission standards to reduce atmospheric contamination. One technique for reducing emissions involves using liquefied natural gas (LNG). The tanks used for the transport and storage of LNG must have very low thermal expansion and high cryogenic toughness. For excellent cryogenic properties, high-Mn steel with a complete austenitic structure is used to design these tanks. We aim to determine the optimum welding conditions for performing Laser-MIG (Metal Inert Gas) hybrid welding through the MIG leading and laser following processes. A welding speed of 100 cm/min was used for welding a 15 mm thick high-Mn steel plate. The welding performance was evaluated through mechanical property tests (tensile and yield strength, low-temperature impact, hardness) of the welded joints after performing the experiment. As a result, it was confirmed that the tensile strength was slightly less than 818.4 MPa, and the yield strength was 30% higher than base material. The low-temperature impact values were equal to or greater than 58 J at all locations in the weld zone. The hardness test confirmed that the hardness did not exceed 292 HV. The results of this study indicate that it is possible to use laser-MIG hybrid welding on thick high-Mn steel plates.

scholarly journals Influence of Post Weld Heat Treatment on the Grain Size, and Mechanical Properties of the Alloy-800H Rotary Friction Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4366
Author(s):  
Saqib Anwar ◽  
Ateekh Ur Rehman ◽  
Yusuf Usmani ◽  
Ali M. Al-Samhan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Heat Affected Zone ◽  
Tensile Testing ◽  
Weld Zone ◽  
Alloy 800H ◽  
Weld Joints ◽  
Heat Treated ◽  
Friction Weld

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.

scholarly journals Microstructure and Mechanical Properties of Heat-Affected Zone of Repeated Welding AISI 304N Austenitic Stainless Steel by Gleeble Simulator

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Energy ◽  
Heat Affected Zone ◽  
Ferrite Content ◽  
Equipment Safety ◽  
Microstructure And Mechanical Properties ◽  
Δ Ferrite ◽  
The Impact

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.

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