Effect of Nickel Content on the Microstructural, Mechanical and Corrosion Behavior of E7018-G Electrode Weld Metal

2021 ◽  
Author(s):  
Masoud Mosallaee ◽  
Milad Toghraei Semiromi
Keyword(s):  
Weld Metal ◽  
Corrosion Behavior ◽  
Nickel Content

The impact of Ni on the corrosion behavior and microstructure of weld metal fabricated from E8018-G electrodes

2020 ◽  
Vol 64 (6) ◽  
pp. 1065-1075
Author(s):  
Majid Fakheri ◽  
Hamid R. Zare ◽  
Zahra Mohammadpour ◽  
Masoud Mosallaee
Keyword(s):  
Weld Metal ◽  
Corrosion Behavior ◽  
The Impact

The Corrosion Behavior about Two Ni-Based Alloys in CO2 / H2S Environments

2010 ◽  
Vol 152-153 ◽  
pp. 1624-1631 ◽  
Author(s):  
Xue Hui Zhao ◽  
Zhen Quan Bai ◽  
Kai Lin ◽  
Yan Han
Keyword(s):  
Corrosion Behavior ◽  
Oil And Gas ◽  
Nickel Content ◽  
Immersion Test ◽  
Pitting Potential ◽  
Fecl3 Solution ◽  
Nickel Base ◽  
Corrosion Pits ◽  
Incoloy 825 ◽  
Energy Disperse Spectroscopy

Today’s global exploration of oil and gas leads to a range of highly corrosive environment that, in turn, require corrosion resistant high nickel content alloys for Oil Country Tubular Goods. Aimed at the problem of oil tube corrosion in environment with high content of H2S and CO2, the corrosion behavior of two nickel based alloys in 15%NaCl solution containing H2S/CO2 in high temperature and high pressure environments were researched. The pitting corrosion behavior of Ni-based alloys were investigated in FeCl3 solution by polarization curve and immersion test. The scanning electron microscopy(SEM), energy disperse spectroscopy(EDS) were applied to analyse the microstructure and corrosion performance of the samples. The results showed that the pitting-resistant of G3 was superior to Incoloy825.With the experimental temperature increasing, the corrosion rates increased and some slight corrosion pits appeared on the surface of Incoloy 825, Its maximum corrosion rate was 0.018mm/a. XRD showed that the corrosion films formed on nickel base alloys were consist of NiS, FeS and the oxides of Ni and Cr. The polarization curves showed that there were different corrosion behavior of two alloys, the anodic curve of G3 has an obvious passivation region, and there has higher pitting potential .

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.

Microstructure and Galvanic Corrosion of Dissimilar Weldment Between Duplex Stainless Steel UNS 31803 and X80 Steel

2009 ◽  
Author(s):  
Xiaoyan Wang ◽  
Lei Zhang ◽  
Xianren Kuang ◽  
Minxu Lu
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Heat Affected Zone ◽  
Galvanic Corrosion ◽  
Base Material ◽  
Nacl Solution ◽  
Gas Field ◽  
X80 Steel

Kela-2 Gas Field is the main supply for the West-East Gas Pipeline which runs across China with length of 4000 kilometers. Natural gas from Kela-2 contains CO2/H2S sour components and 10% condensation water, which makes the medium present very strong corrosivity. In avoidance of corrosion failure, DSS UNS S31803 line pipes were introduced to transmit the gas from the Gas Field to gathering center and processing factory. And it is the first time DSS pipes which is totally about 13km were widely used in oil and gas pipeline around the world. As it is known, DSS UNS S31803 pipes and traditional linepipes X80 were welded together between the gathering lines and mainline. Duplex stainless steel (DSS) UNS S31803 and X80 were welded by metal inertia gas welding (MIG) with consumable ER2209, and the joints take on good mechanical properties. The type II boundary close to the fusion boundary at the carbon steel side was observed by SEM. Obvious concentration gradient of Ni and Cr was observed in the region between the two boundaries, where the hardness was much higher. The weld metal with columnar and some polygonal ferrites take on good passivation against test solution. The heat affected zone beside the X80 base material is mostly granular bainite, some polygonal ferrites and few MA, X80 base material present obvious rolling state, the microstructure of which is the same to X80 heat affected zone, but the level of crystal size reach to 11.6. The corrosion behavior of them dosen’t have any difference, but the corrosion potential of X80 HAZ is much higher than X80 BM, about 50 mv, the corrosion rate of X80 HAZ is also much higher than X80 base material. Potential curves of different weldment regions were also studied in 3.5% NaCl solution and 3.5% NaCl solution with saturated CO2. Galvanic corrosion behavior of weld metal and X80 steel was also tested and the conclusion is: The cathode reaction is controlled by oxygen diffusion, and when area ratio S (S = Ac / Aa, Ac is the area of DSS WM, Aa is the area of X80 BM) increases, corrosion current of X80 is enhanced rapidly, which is called “gathering principle”. When the weld metal and X80 coupled, cathode has much higher polarization potential and is protected completely.

Effect of Small Amount of Bismuth on Corrosion Resistibility of Austenitic Stainless Steel Weld Metals

2002 ◽  
Author(s):  
Yasuhiro Hara ◽  
Keisuke Shiga ◽  
Nobuo Nakazawa
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Weld Metal ◽  
Corrosion Behavior ◽  
Arc Welding ◽  
Steel Weld ◽  
Weld Metals ◽  
Stainless Steel Weld ◽  
Austenitic Stainless Steel Weld ◽  
Welding Processes

Flux-cored are welding (FCAW) has increased recently because of high welding efficiency. However, a small amount of bismuth in the weld metals was a residue from the flux component that was added for improving slag detachability. The effect of small amount of bismuth in austenitic stainless steel weld metal on corrosion behavior in wet corrosion environment is not adequately clear because there is little reported to date. In the present research, the effect of bismuth which remained in the weld metal on the corrosion behavior of 308-type weld metal in wet corrosive solution was examined by using different bismuth containing weld metal. Measurement of the anodic polarization curve in a sulfuric acid solution, determination of pitting potential and conducting stress corrosion cracking (SCC) tests in a chloride solution, and implementation of boiling nitric add solution tests were conducted. In addition, the corrosion behavior of the FCAW weld metal was compared with that of Bi-free weld metals by shielded metal arc welding (SMAW) and gas tungsten arc welding (GTAW) to clarify how the corrosion behavior varies between the welding processes. In this research, no noticeable adverse effect of bismuth remained in the 308-type austenitic FCAW weld metals was observed in corrosion test.

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.

A Decade of Progress in Underwater Wet Welding Using the SMAW Process (1990-2003)

2004 ◽  
Author(s):  
Stephen Liu
Keyword(s):  
Weld Metal ◽  
Nickel Content ◽  
Cost Savings ◽  
Significant Cost ◽  
Electrode Coating ◽  
Underwater Wet Welding ◽  
Recent Developments ◽  
Weld Metal Microstructure ◽  
Metal Microstructure ◽  
Repair Techniques

It is well established that underwater wet welding (UWW) offers significant cost savings over other repair techniques for submerged structures such as petroleum production platforms, ships, and piers. Due to the deleterious effect of increased pressure on weld quality, innovative consumables are required for the production of quality wet welds. Manganese was added to the electrode coating to replenish its loss from the weld pool. Titanium and boron were added to control the molten metal oxygen potential and refine the as-solidified and reheated weld metal microstructure. Rare-earth metals (REM) were added to control the weld metal oxygen content. Finally, weld metal nickel content was optimized to improve impact toughness. Selected results of these approaches are presented in this work. These recent developments clearly demonstrate that it is possible to achieve significant progresses in wet welding using shielded metal arc (SMA) consumables, if these are designed following sound metallurgical principles.

scholarly journals Twin-Wire Pulsed Tandem Gas Metal Arc Welding of API X80 Steel Linepipe

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Wenhao Wu ◽  
Ming Zhao ◽  
Haiyan Wang ◽  
Yanxia Zhang ◽  
Tong Wu
Keyword(s):  
Corrosion Resistance ◽  
Weld Metal ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Arc Welding ◽  
Production Efficiency ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Metal Arc Welding ◽  
X80 Steel

Twin-Wire Pulsed Tandem Gas Metal Arc Welding process with high welding production efficiency was used to join the girth weld seam of API X80 steel linepipe of 18.4 mm wall thickness and 1422 mm diameter. The macrostructure, microstructure, hardness, and electrochemical corrosion behavior of welded joints were studied. Effects of temperature and Cl− concentration on the corrosion behavior of base metal and weld metal were investigated. Results show that the welded joint has good morphology, mechanical properties, and corrosion resistance. The corrosion resistance of both the base metal and the weld metal decreases with increasing temperature or Cl− concentration. In the solution with high Cl− concentration, the base metal and weld metal are more susceptible to pitting. The corrosion resistance of the weld metal is slightly lower than that of the base metal.

scholarly journals Microstructural Analysis of Inconel 625 Nickel Alloy / UNS S31803 Duplex Stainless-Steel Dissimilar Weldments

2019 ◽  
Vol 44 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Tuba Karahan ◽  
Tolga Mert ◽  
Mustafa Tümer ◽  
Zaim Mithat Kerimak
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Nickel Alloy ◽  
Nickel Content ◽  
Microstructural Analysis ◽  
Welding Process ◽  
Inconel 625 ◽  
Electron Microscopes ◽  
Dendritic Austenite

In this study, Inconel 625 nickel alloy and UNS 31803 duplex stainless steel (DSS) dissimilar pairs were welded with MIG welding process. Weld metal, obtained with ERNiCrMo-3 filler wire, was subjected to mechanical and microstructural investigations. Notch impact test and micro hardness measurements were realized on weld metal in order to evaluate31803 mechanical properties. Microstructural changes in fusion line of the base metals were examined using optical and electron microscopes. Phase precipitations rich of Ti and Mo elements were detected among dendritic austenite arms in the weld metal. It was observed that ERNiCrMo-3 filler metal had sufficient toughness because of high nickel content.

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