scholarly journals Influencing the arc and the mechanical properties of the weld metal in GMA-welding processes by additive elements on the wire electrode surface

2016 ◽  
Vol 118 ◽  
pp. 012006 ◽  
Author(s):  
V Wesling ◽  
A Schram ◽  
T Müller ◽  
K Treutler
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Electrode Surface ◽  
Gma Welding ◽  
Wire Electrode ◽  
The Wire ◽  
Welding Processes

scholarly journals Welding Soundness of a Thick-Walled 9Cr-1Mo Steel

2010 ◽  
Vol 654-656 ◽  
pp. 408-411
Author(s):  
Woo Seog Ryu ◽  
Sung Ho Kim ◽  
Dae Whan Kim
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Base Metal ◽  
Hardness Test ◽  
Ultimate Tensile Stress ◽  
Narrow Gap ◽  
Martensitic Steels ◽  
Narrow Gap Welding ◽  
Self Energy ◽  
Welding Processes

High Cr ferritic/martensitic steels are demanded to join using favorable welding processes with economical and metallurgical advantages in order to apply to the thick-walled reactor pressure vessel of a very high temperature gas cooled reactor. Narrow gap welding technology was adopted to weld a thick-walled 9Cr-1Mo-1W steel with thickness of 110mm. The welding integrity was checked by non-destructive examination, optical microscopy and hardness test, and the homogeneity through welding depth was checked by absorbed impact energy and tensile strength. The optimizing welding conditions resulted that a narrow U-grooved gap with almost parallel edges was sound in actual practice, and the coarse grain zone was minimized in the heat affected zone. The absorbed energy of 75±25 J through welding depth was acceptable in scatter band to check the uniformity through the welding depth. The ultimate tensile stress and yield stress were about the same through welding depth at 650±10 MPa and 500±10 MPa, indicating no difference through welding depth. Elongation was also almost same through depth, and the fracture surface was appeared as a normal. The weld metal had similar mechanical properties to base metal. The upper self energy of weld metal was 194J, and the ductile-brittle transition temperature was 30°C. The tensile behavior was the typical trend with temperature, and YS and UTS of weldment were slightly higher than base metal by nearly below 10%. Thus, it concluded that the soundness of the narrow gap welding of a thick-walled 9Cr-1Mo-1W steel was confirmed in terms of the welding uniformity through the depth and mechanical properties.

Mechanical properties and microstructural characteristics of rotating arc-gas metal arc welded carbon steel joints

2021 ◽  
Vol 30 (1) ◽  
pp. 49-58
Author(s):  
Nallasamy Sankar ◽  
Sudersanan Malarvizhi ◽  
Visvalingam Balasubramanian
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Weld Metal ◽  
Gas Metal Arc Welding ◽  
Ferrite Matrix ◽  
Metal Arc Welding ◽  
Rotating Arc ◽  
Steel Joints ◽  
Welding Processes ◽  
Lamellar Pearlite

Abstract The main problem associated with high thickness carbon steel plate's narrow range or “V” groove welding in conventional welding processes is the sagging of the molten pool due to gravity, which in turn leads to defects formation and deteriorates mechanical properties. This problem could be overcome by the rotating arc gas metal arc welding (RA-GMAW) technique. This investigation aims to evaluate mechanical properties and metallurgical characteristics of high thickness IS2062 Gr-B carbon steel joints welded by RA-GMAW technique. The experimental results show that RA-GMAW joint exhibited higher (598 MPa) tensile strength, higher hardness (220 HV) at weld metal region, and lower impact toughness (137 J) than the unwelded base metal. This is due to the presence of fine acicular ferrite and widmanstatten ferrite matrix mixed with fine lamellar pearlite microstructure in the weld metal region.

Rosenhain Centenary Conference - 2. Design implications for materials selection 2.8 Weldability and toughness specifications for structural steels in Japan — with special reference to WES-155 and -156 Keynote speech

1976 ◽  
Vol 282 (1307) ◽  
pp. 258-263
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Stress Corrosion ◽  
Thermal Cycle ◽  
Structural Steels ◽  
Fusion Welding ◽  
Materials Selection ◽  
Keynote Speech ◽  
Welding Processes

The four papers to be covered in this Session concern weldability, toughness, corrosion, stress corrosion and specification requirements. The problem of weldability is dealt with in both the paper by Baker and by Kihara and coauthors. It is first important to decide exactly what is meant by the term weldability however, I would define weldability as the capability of different materials to be joined by a range of different welding processes with the object of giving satisfactory joints which meet the following objectives: 1. Free from harmful defects. 2. With adequate mechanical properties to carry loads which may be applied, that is with adequate strength and toughness. 3. With adequate resistance to long term environmental effects, e.g. creep, corrosion/ stress corrosion, and fatigue. Fusion welding gives rise to the possibility of a number of problems which may occur in any materials being welded, including the possible occurrence of defects, the presence of material in the weld metal when added fillers are used, changed material in the heat affected zone due to the thermal cycle, and the presence of residual stresses

Girth Welding Development of Heavy Wall Materials for Severe Applications

2012 ◽  
Author(s):  
Noé Mota-Solis ◽  
Mauricio Pelcastre ◽  
Eduardo Ruiz ◽  
Philippe Darcis ◽  
Jose Enrique Garcia-Gonzalez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Deep Water ◽  
Filler Material ◽  
Pipe Material ◽  
Transverse Impact ◽  
Line Pipe ◽  
Girth Welding ◽  
Wall Materials ◽  
Welding Processes

The needs for oil and gas exploration in deep water (DW) and ultra-deep water (UDW) severe environments involve critical requirements of heavy wall materials. Offshore DW and UDW impose demanding service conditions of sour environment, mechanical properties, fatigue performance, gas service, high pressure and wide temperature ranges not only for heavy wall seamless line pipe materials but also for the girth weld performance. Thus, the development of heavy wall materials for severe applications is essential for DW and UDW, where complex material requirements are sought. Additionally the girth welding of heavy wall materials has imposed particularities typical of large wall thickness materials’ welding. The latter requires the development of particular solutions for pre-production and GMAW narrow groove offshore welding procedures. The present work presents the development of two welding processes of a heavy wall seamless pipe material: 273.1 mm OD × 46 mm WT, X65 steel grade. Pre-production welding involves STT®+SAW using a dual slope V-bevel, filler material for root processing was an AWS ER80S-G, while welding deposition for fill and cap passes was made using twin-wire technique, with two different electrodes (ENi1K and EG AWS designations), in combination with a neutral flux. On the other hand, narrow groove welding procedure considered a J-bevel, 3° angle, applying STT®+GMAW; filler material for GMAW was as well an ER80S-G AWS designation. Both welding procedures are aimed to deliver adequate mechanical properties to meet sour-service requirements (<250HV10), weld metal overmatching (120 MPa minimum) and toughness (CVN 45JAVE/38JIND) at low temperature. Mechanical characterization included hardness Vickers measurements using a 10 kgf load, tensile tests in all-weld metal and transverse impact fracture Charpy V-notch tests and CTOD tests.

scholarly journals Effects of TIG Reheating on Duplex Stainless Steel Weld Microstructure

2019 ◽  
Vol 4 (1) ◽  
pp. 295-302
Author(s):  
Balázs Varbai ◽  
Ferenc Tolnai ◽  
Kornél Májlinger
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Weld Metal ◽  
Arc Welding ◽  
Nucleation Site ◽  
Chromium Nitrides ◽  
First Case ◽  
Secondary Austenite ◽  
Mechanical Properties And Corrosion ◽  
Welding Processes

Duplex stainless steels (DSS) gaining their excellent mechanical properties and corrosion resistance due to their austenitic-ferritic microstructure, ideally in the same amount. However, to keep this ideal phase ratio during arc welding is very difficult. Generally, the arc welding processes will result in more ferritic microstructure in the weld metal and in the heat affected zone, due to the rapid cooling. The ferritic microstructure can cause chromiumnitride precipitation, because the nitrogen solubility in ferrite phase is very low below 700 °C. These chromiumnitride precipitations can cause loss of corrosion resistance and mechanical properties. However, during subsequent reheating, the chromium-nitrides can dissolve and act as a secondary austenite nucleation site in the ferritic microstructure. In our research we welded DSS specimen autogenously, with tungsten inert gas welding using pure argon and 94 % argon + 6 % nitrogen as shielding gasses. In the first case the sub-sequent solid-state reheating caused 20 % increase in the austenite fraction of the weld metal but with the use of mixed shielding gas only 5 % increase.

Development of Combined Machining Modes, Investigation of Mechanical Properties and Structure of Deformed Semi-Finished Products from Alloy 01417

2020 ◽  
Vol 992 ◽  
pp. 498-503
Author(s):  
S. Sidelnikov ◽  
D. Voroshilov ◽  
M. Motkov ◽  
M. Voroshilova ◽  
V. Bespalov
Keyword(s):  
Mechanical Properties ◽  
Rare Earth Metals ◽  
Electrophysical Properties ◽  
Intermediate Annealing ◽  
Plastic Properties ◽  
Bar Rolling ◽  
Annealing Temperatures ◽  
Continuous Ingot ◽  
The Wire ◽  
Deformation Modes

The article presents the results of studies on the production of wire with a diameter of 0.5 mm from aluminum alloy 01417 with a content of rare-earth metals (REM) in the amount of 7-9% for aircraft construction needs. The deformation modes, the experimental technique and equipment for the implementation of the proposed technology described. The wire was obtained by drawing and bar rolling with subsequent drawing from a rod with a diameter of 5 mm, obtained previously using the process of combined rolling-extruding (CRE) from a continuous ingot with a diameter of 12 mm, cast in an electromagnetic mold (EMM). The wire obtained by the presented technology was subjected to 4 different heat treatment modes with annealing temperatures from 350 to 500 °C and holding time of 1 h in the furnace to achieve mechanical and electrophysical properties corresponding to TS 1-809-1038-2018. The level of strength and plastic properties obtained in the course of research required only one intermediate annealing. The microstructure of the wire was investigated and the modes were revealed that made it possible to obtain the required level of mechanical properties and electrical resistivity, satisfying TS 1-809-1038-2018.

scholarly journals Comprehensive Analysis of the Microstructure and Mechanical Properties of Friction-Stir-Welded Low-Carbon High-Strength Steels with Tensile Strengths Ranging from 590 MPa to 1.5 GPa

2021 ◽  
Vol 11 (12) ◽  
pp. 5728
Author(s):  
HyeonJeong You ◽  
Minjung Kang ◽  
Sung Yi ◽  
Soongkeun Hyun ◽  
Cheolhee Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Joint Strength ◽  
Solid Phase ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
Friction Stir ◽  
Welding Processes

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels.

scholarly journals Enhanced electrical conductivity and mechanical properties in thermally stable fine-grained copper wire

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Qingzhong Mao ◽  
Yusheng Zhang ◽  
Yazhou Guo ◽  
Yonghao Zhao
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Electrical Conductivity ◽  
Yield Strength ◽  
High Speed ◽  
Copper Wire ◽  
Rapid Development ◽  
Dislocation Slip ◽  
Ultrafine Grains ◽  
The Wire

AbstractThe rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.

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