Studies on microstructure and mechanical properties of modified 9Cr–1Mo (P91) steel in submerged arc welding with TiO2-enriched fluxes

To research effect of welding thermal cycle on the microstructure and mechanical properties of welded joint, two pieces of 60mm thick plates were welded together using automatic submerged-arc welding (SAW) method with suitable welding parameters. After 17 passes welding, the microstructures and phases of the welded joint was carefully observed and analyzed by using a Carl Zeiss optical microscope in different zones of welded joint, and the surface micro-hardness of the welded joint was measured systematically by using microscopic-hardness tester Lycra. Afterwards, the mechanical properties of the weld metals were measured through stretching. Through a series of measurements and observations, the welding experiment results indicate that effect of welding thermal cycle on the microstructure and mechanical properties of welding joint is great, the grains of the bottom of the weld metal are certainty smaller and more uniform, and the bottom of the weld metal have more excellent mechanical properties.

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Study on the Organization and Mechanical Properties of Q345R Weld-Joint

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.562-564.573 ◽

2012 ◽

Vol 562-564 ◽

pp. 573-577

Author(s):

Xiao Dong Hu ◽

Yong Zhang ◽

Jian Tao Lv ◽

Sen Zhang

Keyword(s):

Mechanical Properties ◽

Arc Welding ◽

Weld Seam ◽

Weld Zone ◽

Submerged Arc Welding ◽

Butt Weld ◽

Heat Treated ◽

Metallurgical Structure ◽

Submerged Arc ◽

Better Than

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.

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Investigation on Deposited Metal Properties of Homemade Nickel and Nickel-Free Electrodes and Fluxes for Submerged Arc Welding of SA-508 Gr.3 Cl.1

Volume 2: Plant Systems, Structures, Components and Materials ◽

10.1115/icone25-66331 ◽

2017 ◽

Author(s):

Le Mei ◽

Junbao Zhang ◽

Yifeng Huang ◽

Yan Yu ◽

Yong Jiang ◽

...

Keyword(s):

Mechanical Properties ◽

Weld Metal ◽

Arc Welding ◽

Proton Irradiation ◽

Submerged Arc Welding ◽

Impact Property ◽

Welding Material ◽

Weld Metals ◽

Metal Properties ◽

Submerged Arc

Up to now, two kinds of filler metal with or without nickel element for submerged arc welding have been largely used in the reactor pressure vessel (RPV) manufacturing. In order to study the effect of nickel element on weld metal properties of SA-508 Gr.3 Cl.1, submerged arc welding material with nickel (AWS classification F8P4-EGN-F2N, F2 for short) and welding material without nickel (F8P4-EA3N-A3N, A3 for short) were used; and conventional mechanical properties, low-cycle fatigue test, and proton irradiation analysis of the two weld metals were studied. Results show that the mechanical properties of the two different weld metals are similar, except that the Charpy V-notch impact property of the weld metal with nickel is better than that without nickel; the micro-structures of F2 and A3 weld metals are both composed of ferrite base and granular bainite, but the columnar grain size of F2 weld metal is smaller relatively, which results in better impact property. In addition, the irradiated A3 weld metal has fewer dislocation loops than the irradiated F2 weld metal after the same proton irradiation dose; the irradiated weld metals both have higher micro-Vickers hardness than before.

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Microstructure and Mechanical Properties of Extra High Strength Heavy Steel Plate for Bridge Application

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.859 ◽

2014 ◽

Vol 783-786 ◽

pp. 859-866 ◽

Cited By ~ 1

Author(s):

Dong Sheng Liu ◽

Chong Xiang Yue ◽

Huan De Chen ◽

Bing Gui Cheng

Keyword(s):

Mechanical Properties ◽

Arc Welding ◽

Steel Plate ◽

Control Process ◽

High Strength ◽

Submerged Arc Welding ◽

Steel Plates ◽

Weathering Steel ◽

Weld Joints ◽

Submerged Arc

Key parameters for thermomechanical control process (TMCP) and integrated welding operations have been determined to industrialize extra high strength micro-alloyed low carbon SiMnCrMoNiCu steel plates for bridge applications. Confocal Scanning Microscope was used to make In-situ observation on austenite grain growth during reheating. A Gleeble 3800 thermomechanical simulator was employed to investigate transformation behavior of the TMCP conditioned austenite. Integrated industrial rolling trial was conducted to correlate the laboratory observations and commercial production of the plates. Microstructure factors affecting the toughness of the steel were analyzed. Submerged-Arc Welding (SMAW) trails were conducted and the structures and mechanical properties of the weld joints characterized. The representative plate with thickness of 60 mm consisted of acicular ferrite (AF) + refined polygonal ferrite (PF) + granular bainite (GB) across the entire thickness section exhibit yield strength (YS) greater than 560 MPa in transverse direction and excellent Charpy V Notch (CVN) impact toughness greater than 100 J at-40 °C in the parent metal and the weld joints. These provide useful integrated database for producing advanced high strength steel plates via TMCP. Keywords: Thermo-Mechanical Control Process;Weathering Steel Plate for Bridge; Submerged-Arc Welding without Preheating

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