scholarly journals Effect of Heat Treatment and Drawing on High-Manganese Steel Pipe Welded by Gas Tungsten Arc

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1366
Author(s):  
Geon-Woo Park ◽  
Haeju Jo ◽  
Minha Park ◽  
Byung-Jun Kim ◽  
Wookjin Lee ◽  
...  
Keyword(s):  
Weld Metal ◽  
Strain Rate ◽  
Mechanical Twinning ◽  
Steel Pipe ◽  
Manganese Steel ◽  
Columnar Dendrite ◽  
Austenitic Phase ◽  
Gas Tungsten Arc ◽  
Gas Tungsten ◽  
Mn Steel

This study investigated the effect of post-weld processes including annealing and drawing on the microstructure and mechanical properties of high-Mn steel pipes welded by gas tungsten arc welding. The weld metal showed a solidified microstructure having coarse and elongated grains due to coalescence of columnar dendrite into welding heat direction. After post-annealing, the solidified microstructure changed into equiaxed grains due to recrystallization and grain growth. Mn segregation occurred during welding solidification and caused lower stacking fault energy (SFE) in the Mn-depleted region. Although ε-martensite formation in the as-welded state and during deformation was expected due to decreased SFE of the Mn-depleted zone, all regions showed a fully austenitic phase. The annealing process decreased strength due to grain coarsening but increased ductility. The drawing process increased strength of weld metal through work hardening. All pipes showed decreasing strain rate sensitivity (SRS) with deformation and negative SRS after certain strain levels. It was confirmed that negative SRS is related to less formation of mechanical twinning at a higher strain rate. This work provides fundamental insights into manufacturing a high-Mn steel pipe and manipulating its properties with annealing and drawing processes.

Influence of Nitrogen and Heat Input on Weld Metal of Gas Tungsten Arc Welded High Nitrogen Steel

2007 ◽  
Vol 14 (5) ◽  
pp. 259-262 ◽  
Author(s):  
Lin ZHAO ◽  
Zhi-ling TIAN ◽  
Yun PENG ◽  
Yan-chang QI ◽  
Yan-jie WANG
Keyword(s):  
Weld Metal ◽  
Heat Input ◽  
High Nitrogen Steel ◽  
High Nitrogen ◽  
Gas Tungsten Arc ◽  
Nitrogen Steel ◽  
Gas Tungsten

The Effect of High Strain Rate on Properties and Microstructure of the Fully Austenitic High Mn Steel

2016 ◽  
Vol 246 ◽  
pp. 55-58 ◽  
Author(s):  
Anna Śmiglewicz ◽  
Magdalena Jabłońska ◽  
Adam Płachta ◽  
Kinga Rodak ◽  
Rafał Michalik
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Impact Resistance ◽  
Break Point ◽  
Mechanical Twinning ◽  
Manganese Steel ◽  
Structural Investigations ◽  
Bending Tests ◽  
Impact Bending

In the paper, results of impact bending tests of a high-manganese steel of X30MnAlSi26-4-3 grade are presented. The tests were carried out using a flywheel machine, suitable for dynamic tensile tests and impact bending tests in the range of linear velocity of the forcing element from 5 ÷ 40 m/s. The obtained test results were compared with the results of impact resistance of the studied steel determined using Charpy machine. Structural investigations were carried out using light microscope and scanning transmission electron microscopy. Creating a mechanical twins at different strain rates was analyzed. The surfaces of fractures formed in the break point during bending tests were analyzed, and they indicate a presence of mixed transcrystalline fractures with a predominance of plastic fractures. Substructure studies revealed the presence of mechanical twinning induced in a high strain rate for the X30MnAlSi26-4-3 steel.

Microstructural Characterization and Corrosion Behavior of Activated Flux Gas Tungsten Arc-Welded and Multipass Gas Tungsten Arc-Welded Stainless Steel Weld Joints in Nitric Acid

CORROSION ◽  
10.5006/0515 ◽  
2012 ◽  
Vol 68 (8) ◽  
pp. 762-773 ◽  
Author(s):  
A. Ravi Shankar ◽  
S. Niyanth ◽  
M. Vasudevan ◽  
U. Kamachi Mudali
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Delta Ferrite ◽  
Thick Sample ◽  
Weld Joints ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Gas Tungsten

AISI Type 304L (UNS S30403) austenitic stainless steels are widely used in spent nuclear fuel reprocessing plants, and welding is an indispensable tool used for joining these materials. In the present study, manual gas tungsten arc-welded (M-GTAW) and activated gas tungsten arc-welded (A-GTAW) weldments of Type 304L stainless steel were prepared to examine the microstructural and corrosion behavior of the weldments. A total of 6 passes were required to complete the 6 mm thick sample welding, and 16 passes were required for 12 mm thick sample welding using the M-GTAW process, compared to single-pass A-GTAW welding. Characterization of weld joints was done by radiography, optical microscopy, microhardness tester, a feritscope, and scanning electron microscopy (SEM). The optical microstructure of the fusion zone of weld joints showed delta ferrite in various morphologies. The presence of delta ferrite stringers were observed in the weld joints, extending from the weld metal to the base metal. The corrosion rate results showed that the M-GTAW sample showed only a marginal increase in the corrosion resistance when compared to those welded by the single-pass A-GTAW process. SEM examination revealed the morphology of attack in the base metal was predominantly intergranular while in the weld metal it was interdendritic. The SEM micrograph also showed preferential attack of the delta ferrite stringers.

scholarly journals Microstructure and Mechanical Properties of Gas Tungsten Arc Welded High Manganese Steel Sheet

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1167 ◽  
Author(s):  
Geon-Woo Park ◽  
Haeju Jo ◽  
Minha Park ◽  
Sunmi Shin ◽  
Won-Seok Ko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Base Metal ◽  
Steel Sheet ◽  
Weld Zone ◽  
Manganese Steel ◽  
High Manganese ◽  
High Manganese Steel ◽  
Gas Tungsten Arc ◽  
Microstructure And Mechanical Properties

This study investigated microstructure and mechanical properties of high manganese steel sheet fabricated by gas tungsten arc welding (GTAW). The weld zone showed longitudinal coarse grains due to the coalescence of columnar dendrites grown into the direction of heat source, and the HAZ showed equiaxed coarser grains than the base metal due to the thermal effect of GTAW process. Mn segregation occurred in the inter-dendritic regions of the weld zone and Mn depletion thus occurred in the weld matrix. Although the stacking fault energy is expected to be lowered due to the Mn depletion, no noticeable change in the initial phase and deformation mechanism was found in the weld matrix. Lower hardness and strength were shown in the weld zone than the base metal, which was caused by the coarser grain size. The negative strain rate sensitivity observed in the weld zone and the base metal is considered to have originated from the negative strain rate dependency of twinning nucleation stress.

scholarly journals Effect of plasma heat source characteristics on nitrogen absorption in gas tungsten arc weld metal

2013 ◽  
Vol 57 (6) ◽  
pp. 925-932 ◽  
Author(s):  
S. Kodama ◽  
K. Sugiura ◽  
S. Nakanishi ◽  
Y. Tsujimur ◽  
M. Tanaka ◽  
...  
Keyword(s):  
Heat Source ◽  
Weld Metal ◽  
Nitrogen Absorption ◽  
Source Characteristics ◽  
Gas Tungsten Arc ◽  
Gas Tungsten
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