Effect of Chemical Composition of Welding Wire and Low Temperature Steel Plate on the Weld Properties Made by SAW

2008 ◽  
Vol 580-582 ◽  
pp. 57-60
Author(s):  
Hee Joon Sung ◽  
Yeon Baeg Goo ◽  
Kyeong Ju Kim ◽  
Kee Young Choi
Keyword(s):  
Chemical Composition ◽  
Low Temperature ◽  
Weld Metal ◽  
Steel Plate ◽  
Butt Joint ◽  
Welding Wire ◽  
High Hardenability ◽  
Weld Metals ◽  
Weld Properties ◽  
Mo Content

Chemical composition effect on the weld properties for low temperature steel was evaluated. The alloy elements of interest at the weld metal were Cr and Mo, which come from the steel plate and welding wire, respectively. Both side one run SAW process was carried out in a Ygroove butt joint. Microstructure of the weld metal is strongly dependent on the chemical composition of the steel plate and the welding wire, due to high dilution. The microstructure of the weld metal became fine acicular ferrite by increasing Cr and Mo content because of high hardenability effect. The weld metal having Cr and Mo possessed the highest impact toughness at low temperatures among the weld metals studied. Cr seems to have more effect than Mo on the toughness of the weld metal.

scholarly journals Microstructure features and formation mechanism in a newly developed electroslag welding

2021 ◽  
Author(s):  
Tomonori Kakizaki ◽  
Shodai Koga ◽  
Hajime Yamamoto ◽  
Yoshiki Mikami ◽  
Kazuhiro Ito ◽  
...  
Keyword(s):  
Low Temperature ◽  
Weld Metal ◽  
Heat Input ◽  
Acicular Ferrite ◽  
Charpy Impact ◽  
Electroslag Welding ◽  
Weld Metals ◽  
Columnar Grains ◽  
Cooling Speed ◽  
Low Temperature Toughness

AbstractElectroslag welding (ESW) is known to show higher heat input than electrogas welding (EGW), resulting in poor low-temperature toughness. However, a newly developed ESW (dev. ESW) method using low-resistivity slag bath exhibited excellent low-temperature toughness as a result of lower effective heat input than conventional EGW, as demonstrated by the faster cooling rates measured in weld metals and estimated using finite element method analyses. This led to much shallower molten pool in the dev. ESW, resulting in much finer columnar grains and thinner centerline axial grains. High cooling speed in the dev. ESW method appeared to contribute to increased acicular ferrite proportion. The uniform microstructure with large acicular ferrite proportion and small number of inclusions in the weld metal permitted the dev. ESW weld metal to possess little variation in Charpy impact energy across the center of weld metal.

Weld Metal Toughness: Sources of Variation

2010 ◽  
Author(s):  
Marie A. Quintana ◽  
S. S. Babu ◽  
Jeff Major ◽  
Craig Dallam ◽  
Matthew James
Keyword(s):  
Chemical Composition ◽  
Weld Metal ◽  
Mean Value ◽  
Coarse Grained ◽  
Steel Weld ◽  
Bell Curve ◽  
Weld Metals ◽  
Normal Behavior ◽  
Detailed Assessment ◽  
Welding Procedure

Many material properties are statistical in nature. If one measures the same property of the same material repeatedly, ideally the result is a normally distributed “bell” curve about a mean value. This ideal case does not necessarily hold true for all mechanical properties of interest in steel weld metals. Tensile strength measurements tend to exhibit normal behavior for a given weld metal chemical composition deposited using a reasonable consistent welding procedure, Figure 1a. However, toughness measurements are not nearly as well-behaved or predictable. In a tensile test, assuming a defect free weld, the strength measurement is based on the bulk response of the material throughout the gage length. In a Charpy V-notch (CVN) impact test, again assuming a defect free weld, the toughness measurements are controlled largely by the very local response of the material at the point of highest stress where fracture initiates just below the notch. This paper presents a detailed assessment of a C-Mn weld metal and explains how CVN toughness can vary from less than 20 ft-lbf to over 200 ft-lbf in the same weld, often with test specimens located adjacent to one another in the test weld, Figure 1b. The much localized microstructure features that give rise to this degree of variation are a combined result of chemical composition, welding procedure, pass sequence, and individual welder technique. The evidence suggests that retained austenite in coarse grained regions of the as-deposited weld metal transform to martensite at the CVN test temperature, effectively creating local brittle zones in the weld metal. This example provides basis for examination of a broader range of microstructural discontinuities in steel weld metals and their potential influence on toughness measurement.

scholarly journals Effect of Nickel on the Microstructure, Hardness and Impact Toughness of SM570-TMC Weld Metals

2019 ◽  
Vol 269 ◽  
pp. 02007 ◽  
Author(s):  
Nova Arief Setiyanto ◽  
Herry Oktadinata ◽  
Winarto Winarto
Keyword(s):  
Impact Toughness ◽  
Weld Metal ◽  
Nickel Content ◽  
Optical Microscope ◽  
Fusion Welding ◽  
Welding Wire ◽  
Butt Weld ◽  
Weld Metals ◽  
Flux Cored Arc Welding ◽  
The Impact

SM570-TMC steel was applied in the various fields of steel construction where higher strength is required than conventional mild steel. This steel is commonly fabricated by fusion welding where flux-cored arc welding (FCAW) is preferred due to efficiency consideration. In this study, 14 mm thickness of SM570-TMC steel was butt weld by FCAW using three electrode wires with different nickel content (0% Ni, 1% Ni, 1.5% Ni). The microstructure of weldments was studied using an optical microscope. The hardness distribution tests were performed in the heat affected zone, parent metal and weld metal. And impact toughness of weld metals were measured at temperatures of 25 °C, 0 °C and -20 °C. The results show the steel plate welded using welding wire containing 1% Ni provides more superior impact toughness in the weld metal than welding wire 0% Ni, while the impact toughness of the sample which welded using welding wire containing 1.5% tend to decrease. Nickel element which deposited to weld metal by using welding wires containing 1% Ni has improved the impact toughness, but 1.5% Ni may too high which deteriorate impact toughness.

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.

Modifying of microstructure and toughness in the weld metal prepared by welding wire containing nanosized titanium oxides

2021 ◽  
Vol 807 ◽  
pp. 140897
Author(s):  
Xiang Luo ◽  
Zidong Wang ◽  
Xiaohua Chen ◽  
Yanlin Wang ◽  
Guang Xu
Keyword(s):  
Weld Metal ◽  
Titanium Oxides ◽  
Welding Wire

Effects of oxygen content on microstructure and impact toughness of high heat input flux-cored wire weld metals

2018 ◽  
Vol 115 (4) ◽  
pp. 410
Author(s):  
Fengyu Song ◽  
Yanmei Li ◽  
Ping Wang ◽  
Fuxian Zhu
Keyword(s):  
Grain Size ◽  
Impact Toughness ◽  
Weld Metal ◽  
Oxygen Content ◽  
Heat Input ◽  
High Heat ◽  
Cored Wire ◽  
Weld Metals ◽  
High Heat Input ◽  
The Impact

Three weld metals with different oxygen contents were developed. The influence of oxygen contents on the microstructure and impact toughness of weld metal was investigated through high heat input welding tests. The results showed that a large number of fine inclusions were formed and distributed randomly in the weld metal with oxygen content of 500 ppm under the heat input condition of 341 kJ/cm. Substantial cross interlocked acicular ferritic grains were induced to generate in the vicinity of the inclusions, primarily leading to the high impact toughness at low temperature for the weld metal. With the increase of oxygen content, the number of fine inclusions distributed in the weld metal increased and the grain size of intragranular acicular ferrites decreased, which enhanced the impact toughness of the weld metal. Nevertheless, a further increase of oxygen content would contribute to a great diminution of the austenitic grain size. Following that the fraction of grain boundary and the start temperature of transformation increased, which facilitated the abundant formation of pro-eutectoid ferrites and resulted in a deteriorative impact toughness of the weld metal.

scholarly journals EBSD Investigation of the Microtexture of Weld Metal and Base Metal in Laser Welded Al–Li Alloys

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2357 ◽  
Author(s):  
Li Cui ◽  
Zhibo Peng ◽  
Xiaokun Yuan ◽  
Dingyong He ◽  
Li Chen
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Transverse Section ◽  
Grain Morphology ◽  
Structural Features ◽  
Butt Joint ◽  
Horizontal Surface ◽  
Boundary Misorientation ◽  
Texture Intensity ◽  
Highly Correlated

Autogenous laser welding of 5A90 Al–Li alloy sheets in a butt-joint configuration was carried out in this study. The microstructure characteristics of the weld metal and base metal in the horizontal surface and the transverse section of the welded joints were examined quantitatively using electron back scattered diffraction (EBSD) technique. The results show that the weld metal in the horizontal surface and the transverse section exhibits similar grain structural features including the grain orientations, grain shapes, and grain sizes, whereas distinct differences in the texture intensity and misorientation distributions are observed. However, the base metal in the horizontal surface and the transverse section of the joints reveals the obvious different texture characteristics in terms of the grain orientation, grain morphology, predominate texture ingredients, distribution intensities of textures, and grain boundary misorientation distribution, resulting in the diversity of the microhardness in the base metal and the softening of the weld metal. However, the degree of the drop in the hardness of the weld metal is highly correlated to the microtexture developed in the base metal.

Evaluation of FCAW Consumables for Offshore and Arctic Structure Fabrication

1993 ◽  
Vol 115 (1) ◽  
pp. 76-82 ◽  
Author(s):  
S. R. Bala ◽  
L. Malik ◽  
J. E. M. Braid
Keyword(s):  
Weld Metal ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Inclusion Content ◽  
Ambient Temperatures ◽  
Weld Metals ◽  
Arctic Regions ◽  
Flux Cored Arc Welding ◽  
Crack Tip Opening ◽  
Cored Wires

A primary consideration in the welding of structures for service in Canadian offshore and arctic regions is the toughness of weld metals required at very low ambient temperatures (−30°C to −60°C). To assess the suitability of cored wires for applications in these environments, some currently available commercial consumables for the flux-cored arc welding (FCAW) process were evaluated. Cored wires belonging to four different categories: basic, rutile, metal-cored and innershield, were used to prepare welds with similar welding procedures. Weld metal Charpy V-notch (CVN) and crack tip opening displacement (CTOD) tests were carried out and the effect of weld metal composition, microstructure and inclusion content in the weld metal toughness was examined. The Charpy transition temperatures and the CTOD toughness results indicated that, of the 16 wires tested, there were only seven that would be suitable for critical applications.

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