scholarly journals The role of addition of Ni on the microstructure and mechanical behaviour of C-Mn weld metals DOI: 10.5585/exacta.v5i1.1037

Exacta ◽  
2008 ◽  
Vol 5 (1) ◽  
Author(s):  
Vicente Braz da Trindade ◽  
João Da Cruz Payão ◽  
Luís Felile Guimarães Souza ◽  
Ronaldo Da Rocha Paranhos
Keyword(s):  
Heat Treatment ◽  
Weld Metal ◽  
Nickel Content ◽  
Stress Relief ◽  
Impact Testing ◽  
Microstructural Refinement ◽  
Weld Metals ◽  
The Impact ◽  
Submerged Arc

The aim in this work is to study the influence of nickel content (as-welded state and after stress relief heat treatment) on the microstructure and toughness of CMn weld metals obtained with submerged arc welding. The nickel content vary between 0.50 wt.% and 3.11 wt.%. The microstructures were observed using optical microscopy (OM) and scanning electron microscopy (SEM). The toughness was evaluated by Charpy-V impact testing in samples cut transversally to the weld bead. The impact energy showed that nickel content up to 1 wt.% improves the toughness due to the increase of the acicular ferrite (AF) content and microstructural refinement. On the other hand, higher nickel contents have a deleterious effect on the toughness due to the presence of the microconstituent martensite-austenite (M-A) in the weld metal. The stress relief heat treatment did not improve too much the weld metal toughness, even the M-A suffering decomposition (ferrite+carbide). This may be explained by the precipitation of carbides along the boundaries of the ferrite.

The role of addition of Ni on the microstructure and mechanical behaviour of C-Mn weld metals

Exacta ◽  
2008 ◽  
Vol 5 (1) ◽  
Author(s):  
Vicente Braz da Trindade ◽  
João Da Cruz Payão ◽  
Luís Felile Guimarães Souza ◽  
Ronaldo Da Rocha Paranhos
Keyword(s):  
Heat Treatment ◽  
Weld Metal ◽  
Nickel Content ◽  
Stress Relief ◽  
Impact Testing ◽  
Microstructural Refinement ◽  
Weld Metals ◽  
The Impact ◽  
Submerged Arc

The aim in this work is to study the influence of nickel content (as-welded state and after stress relief heat treatment) on the microstructure and toughness of CMn weld metals obtained with submerged arc welding. The nickel content vary between 0.50 wt.% and 3.11 wt.%. The microstructures were observed using optical microscopy (OM) and scanning electron microscopy (SEM). The toughness was evaluated by Charpy-V impact testing in samples cut transversally to the weld bead. The impact energy showed that nickel content up to 1 wt.% improves the toughness due to the increase of the acicular ferrite (AF) content and microstructural refinement. On the other hand, higher nickel contents have a deleterious effect on the toughness due to the presence of the microconstituent martensite-austenite (M-A) in the weld metal. The stress relief heat treatment did not improve too much the weld metal toughness, even the M-A suffering decomposition (ferrite+carbide). This may be explained by the precipitation of carbides along the boundaries of the ferrite.

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.

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 Pengaruh Waktu Penahanan pada Perlakuan Panas Paska Pengelasan terhadap Ketangguhan Sambungan Las Baja

2019 ◽  
Vol 13 (2) ◽  
pp. 80
Author(s):  
Muhamad Fitri ◽  
Bambang Sukiyono ◽  
Martua Limido Simanjuntak
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Local Heating ◽  
Post Weld Heat Treatment ◽  
Impact Testing ◽  
Holding Time ◽  
Aisi 4130 ◽  
The Impact ◽  
Holding Temperature ◽  
Weld Heat

One of the welding methods that is widely used today because it is easier to operate, more practical in its use, can be used for all welding positions and more efficient is called Shield Metal Arc Welding (SMAW). In this welding, the base metal and filler metal will experience thermal cycles which lead to local heating and cooling processes resulting in residual stress and distortion in the material. This residual stress must be removed because it causes a decrease in the mechanical properties of the material. The most widely used method is the thermal method that is by Post Weld Heat Treatment (PWHT). The success of The post-weld heat treatment in removing residual stresses in PWHT is influenced by the holding time. This study aims to examine the effect of holding time on heat treatment, on the weld toughness of steel. In this study, the type of welding used was SMAW welding, the material used was steel AISI 4130, the electrodes used were LB-7018-1 standard application and AWS classification A5.1 E7018-1. The test holding temperature is 650oC. The holding time of testing uses three variables, namely: 2.5 hours, 4.5 hours, 6.5 hours. The Impact testing is done by the Charpy method. From this study, the influence of holding time variation on PWHT holding temperature on the weld strength of AISI 4130 steel was obtained.

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

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.

scholarly journals Analytical Model to Compare and Select Creep Constitutive Equation for Stress Relief Investigation during Heat Treatment in Ferritic Welded Structure

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 688
Author(s):  
Mengjia Hu ◽  
Kejian Li ◽  
Shanlin Li ◽  
Zhipeng Cai ◽  
Jiluan Pan
Keyword(s):  
Heat Treatment ◽  
Constitutive Equation ◽  
Analytical Model ◽  
Stress Relief ◽  
Treatment Temperature ◽  
Hole Drilling ◽  
One Dimensional ◽  
Welded Structure ◽  
The One ◽  
The Impact

The one-dimensional analytical model was promoted to help select the creep constitutive equation and predict heat treatment temperature in a ferritic welded structure, along with neglecting the impact of structural constraint and deformation compatibility. The analytical solutions were compared with simulation results, which were validated with experimental measurements in a ferritic welded rotor. The as-welded and post weld heat treatment (PWHT) residual stresses on the inner and outer cylindrical surfaces were measured with the hole-drilling method (HDM) for validation. Based on the one-dimensional analytical model, different effects of Norton and Norton-Bailey creep constitutive equation on stress relief during heat treatment in a ferritic welded rotor were investigated.

scholarly journals The influence of the oxygen equivalent in a gas-mixture on the structure and toughness of microalloyed steel weldments

2006 ◽  
Vol 71 (3) ◽  
pp. 313-321 ◽  
Author(s):  
Radica Prokic-Cvetkovic ◽  
Andjelka Milosavljevic ◽  
Aleksandar Sedmak ◽  
Olivera Popovic
Keyword(s):  
Impact Toughness ◽  
Crack Propagation ◽  
Weld Metal ◽  
Acicular Ferrite ◽  
Microalloyed Steel ◽  
Gas Mixtures ◽  
Gas Mixture ◽  
Weld Metals ◽  
Maximum Crack ◽  
The Impact

Testing were carried out on two steels. The first was microalloyed with Nb and second with Ti, Nb and V. The impact toughness of weld metals of these steels was evaluated using an instrumented Charpy pendulum. Five different gas mixtures (Ar, CO2, O2) were used to determine the optimal gas shielded metal arc process for both steels. The oxygen equivalent was used as a representative parameter of a mixture to follow, in particularly, its effect on the microstructure, toughness and crack propagation energy of the weld metal. For these investigated steels, the optimum gas mixture was established (5%CO2, 0.91%O2, balance Ar), which provided the maximum crack propagation energy, due to the microstructure which consisted dominantly of acicular ferrite.

Effect of N2 Addition on Microstructure and Properties of SAF 2507 Duplex Stainless Steels GTAW Welded Joint

2012 ◽  
Vol 724 ◽  
pp. 127-130
Author(s):  
Dong Fang Du ◽  
Jie Liu ◽  
Guo Ping Li ◽  
Jin Ming Liu
Keyword(s):  
Weld Metal ◽  
Impact Energy ◽  
Welded Joint ◽  
Welding Process ◽  
Welding Parameters ◽  
Shielding Gas ◽  
Micro Hardness ◽  
Weld Metals ◽  
Welding Arc ◽  
The Impact

In this paper, SAF2507 duplex stainless steel (DSS) was welded by GTAW with ER2594 as filler wire, and Ar + N2 as shielding gas. The results show that, with increasing the content of N2 in the shielding gas, the amount of austenite in weld metal increase, the micro-hardness drops and impact energy increases; the use of Ar +2 ~ 3% N2 welding parameters, the microstructure and mechanical properties of welded joints are the best, the austenitic rates and impact energy of weld metals are 51%~53% and 75~88 J, respectively, and the welding process is easy to control; when the content of N2 reach 5%, the impact energy of weld metal decreases obviously and the welding arc is unstable.

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