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.

Computer Prediction of Phase Fraction in Multipass Weld of Duplex Stainless Steel - Proposal of Microstructural Improvement Welding Process -

2021 ◽  
Vol 1016 ◽  
pp. 206-212
Author(s):  
Kazuyoshi Saida ◽  
Tomo Ogura ◽  
Shotaro Yamashita ◽  
Yusuke Oikawa
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Microstructural Analysis ◽  
Kinetic Equations ◽  
Welding Process ◽  
Phase Fraction ◽  
Isothermal Heat Treatment ◽  
Computer Prediction ◽  
Incremental Method ◽  
Multipass Weld

Computer simulation of the α/γ phase transformation in multipass weld of duplex stainless steel was made for predicting the distribution of the γ phase fraction in the weld metal (WM) and HAZ. The kinetic equations including rate constants of the dissolution behaviour as well as precipitation behaviour of γ phase were determined by isothermal heat treatment test. Based on the kinetic equations determined, the distribution of the γ phase fraction in multipass weld of duplex stainless steel was calculated applying the incremental method combined with the heat conduction analysis in welding process. The γ phase fraction was reduced in the higher temperature HAZ and WM, however, that in the reheated HAZ and WM was increased and recovered to the base metal level. Microstructural analysis revealed that the calculated results of the γ phase fraction in multipass weld were consistent with experimental ones. Based on the computer prediction, the microstructural improvement welding (“reheat bead welding”) process, with analogous concept to the temper bead welding technique, was newly proposed for recovering the γ phase fraction in weld even in the as-welded situation.

Correlation between microstructural gradient and microindentation properties of dissimilar weld between INCONEL 625 and Duplex Stainless Steel

2020 ◽  
Vol 117 (4) ◽  
pp. 407
Author(s):  
Ammar Chabbi ◽  
Mabrouk Bouabdallah ◽  
Sergio Sao-Joao ◽  
Achraf Boudiaf ◽  
Guillaume Kermouche
Keyword(s):  
Stainless Steel ◽  
Elastic Modulus ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Heat Affected Zone ◽  
Laves Phase ◽  
Inconel 625 ◽  
Secondary Phases ◽  
Dissimilar Weld ◽  
Scanning Electron

Microstructure evolution and microindentation properties of dissimilar weld between Inconel 625 nickel based alloy and UNS S32205 Duplex Stainless Steel have been investigated in the current study. Samples in cross-section areas were prepared to investigate microstructure and micromechanical properties in different regions of weld using optical microscopy, scanning electron microscopy and indentation measurements. Typical solidification microstructures were observed. Secondary phases were noticed in both the weld metal and heat affected zone of Inconel 625 alloy at cellular and interdendritic region in lamellar, rod shaped and cuboidal form. These secondary phases were identified as Laves phase and carbonitrides of Nb and Ti. Mechanical properties including elastic modulus and hardness were estimated across the weld joint. The results showed that the weld metal exhibit the lowest values of hardness and elastic modulus, however the Heat Affected Zone of the stainless steel exhibit the highest values owing to high δ-ferrite amount. In-situ nanoindentation coupled with Scanning Electron Microscope was carried out in Laves phase and the matrix weld in order to evaluate nanohardness. The result showed that the nanohardness of Laves phase is too great compared to the weld matrix.

Structure and mechanical properties of laser-MIG hybrid welded SAF 2507 super duplex stainless steel joints

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940037 ◽  
Author(s):  
Kai Qi ◽  
Ruifeng Li ◽  
Guangjin Wang ◽  
Zhe Sun
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Phase Distribution ◽  
Welding Process ◽  
Austenite Phase ◽  
Welding Parameters ◽  
Super Duplex Stainless Steel ◽  
Phase Balance

Joining of super duplex stainless steel (SDSS) is still a challenge, in particular, the need to control the phase balance in the weld metal. In this paper, laser-MIG hybrid welding process was used to join SAF 2507 SDSS plates. The effects of welding parameters on weld appearance, microstructure and phase distribution and mechanical properties were studied systematically. Results showed that the arc/laser hybrid effect was more significant when the arc led the laser with 2 mm distance. It was indicated that arc current mainly affected the weld width while laser power mainly affected weld penetration depth. The composition and microstructure varied a lot at different positions in the weld due to the differences in peak temperature and cooling rate. From top to root, the content of ferrite phase increased and austenite phase decreased. With optimized welding parameters, due to the increase of heat input and the introduction of welding wire, the ferrite/austenite phase balance in the weld metal was obtained. Mechanical property tests showed that the joints exhibited higher tensile strength but lower toughness compared to base metal.

Thermographic and Microstructural Analysis of Martensitic Stainless Steel ASTM A743 CA6NM Arising out of Layered GMA Welding Process Using AWS 410 NiMo Welding Wire

2014 ◽  
Vol 936 ◽  
pp. 1303-1311
Author(s):  
Matheus Tabata Santos ◽  
Palloma Vieira Muterlle ◽  
Guilherme Caribé de Carvalho
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
High Resistance ◽  
Martensitic Stainless Steel ◽  
Fatigue Cracks ◽  
Microstructural Analysis ◽  
Base Material ◽  
Welding Process ◽  
Thick Sheet ◽  
Welding Wire

The martensitic stainless steel ASTM A743 CA6NM is typically used in the production of hydroelectric turbines due to its known high resistance to cavitation induced surface damages. Despite the fact the material presents a high resistance to cavitation, depending on the loading condition to which the turbine runner is subjected and on its geometry, fatigue cracks can develop, thus requiring repair by means of removing material around the crack, up to its complete elimination, and by depositing weld metal in the cavity followed by a grinding process, in order to recover the original runner geometry. Such a repair process is normally done on site, which means that it is not possible to carry out the post weld heat treatment necessary to bring the newly deposited weld metal and the base metal to the same microstructure encountered in the runner when it comes out of manufacture. In order to study the effect that a layered welding has on the base material and on the weld metal, this work aims at studying the microstructural changes that occur in the CA6NM stainless steel welded in multiple layers with a AWS 410 NiMo welding wire. In order to attain such an objective, several 410 NiMo weld beads were deposited in successive layers on the border of a 5mm thick sheet while the resulting temperature fields were monitored by a thermographic camera. After the welding process, the samples cut from the welded sheet were examined in the perpendicular direction of deposition and their resulting microstructures where analyzed and correlated with the temperature history recorded during the welding process. Hardness tests were also carried out.

Assessment of Dissimilar Weld Between Duplex Stainless Steel Grades for Severe Corrosive Applications

2017 ◽  
Author(s):  
Venkatesan Paranthaman ◽  
K. Shanmuga Sundaram
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Microstructural Analysis ◽  
Welding Process ◽  
Charpy Impact ◽  
Dissimilar Welding ◽  
Dissimilar Weld ◽  
Steel Grades ◽  
Steel Aisi ◽  
Stainless Steel Aisi

This paper deals with the investigations on dissimilar weld between two duplex stainless steel grades AISI 2205 and AISI 2507. Increasing use of duplex stainless steel grades instead of austenitic stainless steel grades are growing day by day. This study is an effort in this direction in particularly focusing the dissimilar welding of super duplex stainless steel (AISI 2507) and commercial duplex stainless steel (AISI 2205) grades. Gas tungsten arc welding process was used in this study to fabricate the defect free weld plate. Microstructural analysis on dissimilar weld was carried out to study the diffusion of alloying elements. Micro hardness analysis, Charpy impact toughness test, tensile test and formability test were carried out and the properties were compared with their corresponding base metal properties. Hot corrosion test was carried out to study the feasibility of dissimilar weld in severe corrosive applications. The findings of this paper try to fulfill the applications where commercial duplex stainless steel grades are frequently gets affected in the weld region due to the severity of corrosive environments and due to the sacrificing weld properties.

Microstructural evolution and mechanical integrity relationship of dissimilar metal welding between 2205 duplex stainless steel and composite bimetallic plates

2021 ◽  
pp. 095440622110036
Author(s):  
Changqing Ye ◽  
Weiguo Zhai ◽  
Guangyao Lu ◽  
Qingsong Liu ◽  
Liang Ni ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Intergranular Corrosion ◽  
Thermal Cycle ◽  
Filler Metal ◽  
2205 Duplex Stainless Steel ◽  
Welding Thermal Cycle ◽  
Intergranular Corrosion Resistance

In this paper, shielded metal arc welding on the dissimilar joint between 2205 duplex stainless steel and composite bimetallic plates (304 L stainless steel/10CrNi3MoV steel) with a filler metal E2209 was performed. Furthermore, the microstructure, phase, mechanical properties and intergranular corrosion resistance of the joints were investigated and element distributions of the interfaces were characterized. The results show that austenite transformed to ferrite under the influence of welding thermal cycle, and then a large amount of ferrite appeared in heat affected zone (HAZ) of 2205 duplex stainless steel. Coarse bainite grains were formed in HAZ of the 10CrNi3MoV steel near the fusion line with high temperature welding thermal cycle. Fine granular bainite was also generated in HAZ of 10CrNi3MoV steel due to the relatively short exposure time to the active temperature of grain growth. Local peak temperature near the base 10CrNi3MoV steel was still high enough to recrystallize the 10CrNi3MoV steel to form partial-recrystallization HAZ due to phase change. The filler metal was compatible with the three kinds of base materials. The thickness of the elemental diffusion interfaces layers was about 100 µm. The maximum microhardness value was obtained in the HAZ of 2205 duplex stainless steel (287 ± 14 HV), and the minimum one appeared in HAZ of SS304L (213 ± 5 HV). The maximum tensile strength of the welded joint was about 670 ± 6 MPa, and the tensile specimens fractured in ductile at matrix of the composite bimetallic plates. The impact energy of the weld metal and HAZ of the 10CrNi3MoV steel tested at –20 °C were 274 ± 6 J and 308 ± 5 J, respectively. Moreover, the intergranular corrosion resistance of the weldment including 304 L stainless steel, weld metal, HAZs and 2205 duplex stainless steel was in good agreement with the functional design requirements of materials corrosion resistance.

METALLURGICAL AND CORROSION CHARACTERIZATION OF POST WELD HEAT TREATED DUPLEX STAINLESS STEEL (UNS S31803) JOINTS BY FRICTION WELDING PROCESS

2016 ◽  
Vol 23 (03) ◽  
pp. 1650013 ◽  
Author(s):  
MOHAMMED ASIF M. ◽  
KULKARNI ANUP SHRIKRISHNA ◽  
P. SATHIYA
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Friction Welding ◽  
Volume Fraction ◽  
Welding Process ◽  
Equilibrium Temperature ◽  
Weld Interface ◽  
Heat Treated ◽  
Weld Heat

The present study focuses on the metallurgical and corrosion characterization of post weld heat treated duplex stainless steel joints. After friction welding, it was confirmed that there is an increase in ferrite content at weld interface due to dynamic recrystallization. This caused the weldments prone to pitting corrosion attack. Hence the post weld heat treatments were performed at three temperatures 1080[Formula: see text]C, 1150[Formula: see text]C and 1200[Formula: see text]C with 15[Formula: see text]min of aging time. This was followed by water and oil quenching. The volume fraction of ferrite to austenite ratio was balanced and highest pit nucleation resistance were achieved after PWHT at 1080[Formula: see text]C followed by water quench and at 1150[Formula: see text]C followed by oil quench. This had happened exactly at parameter set containing heating pressure (HP):40 heating time (HT):4 upsetting pressure (UP):80 upsetting time (UP):2 (experiment no. 5). Dual phase presence and absence of precipitates were conformed through TEM which follow Kurdjumov–Sachs relationship. PREN of ferrite was decreasing with increase in temperature and that of austenite increased. The equilibrium temperature for water quenching was around 1100[Formula: see text]C and that for oil quenching was around 1140[Formula: see text]C. The pit depths were found to be in the range of 100[Formula: see text]nm and width of 1.5–2[Formula: see text][Formula: see text]m.

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