This research article reported the weldability, microstructure and mechanical properties of the dissimilar combinations of nickel alloys such as Monel 400 and Hastelloy C276. Multi-pass pulsed current gas tungsten arc (PCGTA) welding was employed for joining these dissimilar metals using ERNiCrMo-3 filler. Interface microstructures showed the absence of unmixed zone at the HAZ of both the sides. It was evident from the studies that all the tensile failures occurred at Monel 400 side. The average impact toughness portrayed by these dissimilar weldments was found to be 41. J. Bend test results showed that these dissimilar combinations offer augmented ductility. The outcomes of the study substantiated the use of current pulsing for the successful joints of Monel 400 and Hastelloy C276 by correlating the mechanical and metallurgical properties. © 2014 Elsevier Ltd.

Devendranath Ramkumar K

Department of Manufacturing Engineering

School of Mechanical Engineering

Vellore Campus

Manikandan M

Department of Design and Automation

Arivazhagan N

Joshi V

Pandit S

Agrawal M

Kumar O.S

Periwal S

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Materials & Design

The pulsating current approach in <a href="https://www.sciencedirect.com/topics/engineering/tungsten">tungsten</a> <a href="https://www.sciencedirect.com/topics/engineering/inert-gas">inert gas</a> (TIG) welding is adapted for joining <a href="https://www.sciencedirect.com/topics/engineering/hastelloy">Hastelloy</a> C-276. <a href="https://www.sciencedirect.com/topics/engineering/microstructure">Microstructure</a> examination revealed the absence of micro-segregation while employing UNS N06022 filler. Due to the prevalence of <a href="https://www.sciencedirect.com/topics/engineering/high-tensile-stress">higher tensile stresses</a> in the un-peened conditions, tensile failures were observed in the weld regions of both the joints irrespective of fillers. Low <a href="https://www.sciencedirect.com/topics/engineering/energy-engineering">energy</a> <a href="https://www.sciencedirect.com/topics/engineering/laser-shock-peening">laser shock peening</a> without coating (LSPwC) was carried out on the weld zones on both the sides of the joints with the pulse densities 2500 and 7500 pulses per cm2. This <a href="https://www.sciencedirect.com/topics/engineering/laser-surface-treatment">laser surface treatment</a> had remarkably increased the <a href="https://www.sciencedirect.com/topics/engineering/tensile-strength">tensile strength</a> of the welded joints by shifting the location of tensile failures well away from the fusion zones for all the cases. Similarly, a considerable increase is observed in the <a href="https://www.sciencedirect.com/topics/engineering/notch-toughness">notch toughness</a> of both the joints in the LSPwC condition. The enhancement in tensile strength and notch <a href="https://www.sciencedirect.com/topics/engineering/impact-toughness">impact toughness</a> of the welds could be ascribed to the <a href="https://www.sciencedirect.com/topics/engineering/compressive-residual-stress">residual compressive stresses</a> induced which were then confirmed by Sin2ψ method in <a href="https://www.sciencedirect.com/topics/engineering/x-ray-diffraction">X-ray diffraction</a> (XRD) technique.

Journal of Materials Processing Technology

Effect of low energy laser shock peening on the mechanical integrity of Hastelloy C-276 welds

Dissimilar welds of Monel 400 and AISI 316 are extensively used in boiler feedwater heat exchanges, petrochemical industries, nuclear industries where moderate weld strength and high corrosion resistance are required. In this paper, dissimilar welded joint between Monel 400 and AISI 316 have been developed by employing Tungsten Inert Gas (TIG), pulsed TIG and Interpulse TIG welding techniques. The heat input rates and filler wire for joining the base metals were same for three welding techniques. The developed weldments have been inspected by employing X-ray Radiography Test (XRT) to determine the macro/ micro defects. The tensile properties of weldments have been evaluated. The ultimate strength of TIG, pulsed TIG and Interpulse TIG weldments were observed to be 528 MPa, 542 MPa and 588 MPa, respectively. The tensile properties of Interpulse TIG weldments are superior to that of welds made of other two welding techniques. © 2019 Elsevier Ltd. All rights reserved.

Materials Today: Proceedings

Effect of TIG, pulsed TIG and Interpulse TIG welding techniques on weld strength of dissimilar joints between Monel 400 and AISI 316

The present investigation deals with the weldability, structure – property relationship of dissimilar metallurgical joints involving Nickel based superalloy Inconel 718 and ferritic stainless steel AISI 430 using pulsed current gas tungsten welding (PCGTAW) process employing ER2553 and ERNiCrMo-4 filler wires. NDT analysis and macrostructure examination corroborated for defect free weldments. Microstructure studies revealed the presence of unmixed zone at the weld interface of Inconel 718 whereas grain coarsening effect was observed at the heat effected zone (HAZ) of AISI 430. Both cellular and equiaxed dendrites were dominated at the fusion zone of ERNiCrMo-4 weldment; whereas different types of ferrite morphologies such as delta and widmanstätten ferrite were observed at the cap and middle zones of ER2553 fusion zone respectively. It was opined that the tensile failures occurred at the parent metal of AISI 430 for both the fillers. Charpy V-notch studies showed that ERNiCrMo-4 weldment exhibited better impact toughness than ER2553 weldment. Similarly the bend test also recommended the use of ERNiCrMo-4 filler due to the acquaintance of excellent bending strength and soundness. This study also addressed the structure – property relationships of these weldments. The outcomes of the study would be highly beneficial to the nuclear, aerospace and petrochemical industries. © 2017 Portuguese Society of Materials (SPM)

Ciência & Tecnologia dos Materiais

Investigations on the structure – property relationships of PCGTA welds involving Inconel 718 and AISI 430

Alloy 686 is a highly corrosion resistant 21st-Century Nickel based superalloy derived from Ni-Cr-Mo ternary system. The alloying elements chromium (Cr) and molybdenum (Mo) are added to improve the resistance to corrosion in the broad range of service environment. The presence of a higher percentage of alloying elements Cr and Mo lead to microsegregation and end up with hot cracking in the fusion zone of Nickel-based superalloys. However, there is scanty of information regarding the welding of alloy 686 with respect to the microsegregation of alloying elements. The present study investigates the possibility of bringing down the microsegregation to cut down the formation of secondary phases in the fusion zone. The weld joints were fabricated by Gas Tungsten Arc Welding (GTAW) and Pulsed current gas tungsten arc welding (PCGTAW) with ERNiCrMo-10 filler and without filler wire (autogenous) mode. The microstructural properties of the weld joints were studied with optical and Scanning Electron Microscope (SEM). The joints fabricated by pulsed current (PC) technique shows refined microstructure, narrower weld bead and practically no heat affected zone (HAZ). Scanning Electron Microscope demonstrates the presence of secondary phases in the interdendritic regions of GTAW case. Energy Dispersive X-ray Spectroscopy (EDS) analysis was carried out to evaluate the microsegregation of alloying element. The results show that the segregation of Mo noticed in the interdendritic zone of GTAW both autogenous and filler wire. Tensile and Impact tests were done to evaluate the strength, ductility, and toughness of the weld joints. The results show that the PCGTA helps to obtain improved strength, ductility and toughness of the weld joints compared to their respective GTAW. Bend test did not lead to cracking irrespective of the type of welding adopted in the present study. © 2017 Elsevier B.V.

Materials Science and Engineering: A

Development of welding technology for improving the metallurgical and mechanical properties of 21st century nickel based superalloy 686

This research study articulates the joining of marine grade alloys Monel 400 and AISI 904L by pulsed current gas tungsten arc welding (PCGTAW) technique using ERNiCu-7 and ERNiCrMo-4 filler metals. Experimental studies were carried out to establish the structure-property relationships of the dissimilar weldments. Microstructure studies corroborated the formation of migrated grain boundaries at the fusion zone of ERNiCrMo-4 weldments. Also a partially melted zone (PMZ) was observed at the weld interface of Monel 400 while using ERNiCrMo-4 filler. Tensile studies corroborated that the joint strength was found better for the ERNiCu-7 weldments compared to ERNiCrMo-4 weldments. Tensile failures occurred at the HAZ of Monel 400 for ERNiCrMo-4 weldments which could be reasoned out to the presence of partially melted zone (PMZ). Charpy V-notch studies demonstrated that both the weldments absorbed higher amount of energy by showing ductile mode of fracture. The outcomes of the present study will be beneficial to the industries operating these metals. © 2015 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.

Journal of Manufacturing Processes

Development of pulsed current gas tungsten arc welding technique for dissimilar joints of marine grade alloys

Bimetallic combinations of Monel 400 and Hastelloy C276 are widely used in the high temperature applications. This paper investigates the weldability of these metals by Gas Tungsten Arc Welding technique employing ERNiCrMo-3 filler wire. Studies were carried out to characterize the weldments for its mechanical and metallurgical properties. Tensile tests confirmed that the strength of the weld zone is higher as compared to the parent metals. Structure-property relationships have been studied using the combined techniques of optical microscopy and SEM/EDAX analysis.

Fulltext

Procedia Engineering

Investigations on Mechanical and Metallurgical Properties of Dissimilar Continuous GTA Welds of Monel 400 and C-276

This investigation has been performed to characterize the microstructure and mechanical properties of the GTA and PCGTA welded dissimilar combinations of Inconel 625 superalloy and AISI 304 austenitic stainless steel. These welds were obtained by employing ERNiCrMo-3 filler metal. The weldments were characterized by the combined techniques of optical microscopy and SEM/EDAX analysis. Hardness and tensile studies were conducted to assess the mechanical properties of the weldments. Tensile studies showed that the fracture had occurred at the parent metal of AISI 304 side in both the cases.

ISIJ International

Characterization of Microstructure and Mechanical Properties of Inconel 625 and AISI 304 Dissimilar Weldments

Dissimilar metal welding involving AISI 304 and Monel 400 finds widespread use in marine and offshore environments for the fabrication of heat exchangers, evaporators, piping and vessels in petrochemical and power generation industries. However studies on the performance of such weldments are scantly found in the literature even though the individual metals have higher corrosion resistance and strength. This paper reports the work carried out on welding of AISI 304 and Monel 400 using Gas Tungsten Arc Welding (GTAW) technique to examine the weldability, mechanical and metallurgical properties. Investigations have been carried out on the hot corrosion behavior of these joints subjected to cyclic air oxidation and K2SO4&nbsp;+&nbsp;NaCl (60%) molten salt environment at 600&nbsp;°C. A comparative analysis was carried out on these weldments for two different filler metals such as E309L and ENiCu-7. The oxide scales formed on the various zones of the weldment have been characterized systematically using surface analytical techniques. Weld zone was found to be more susceptible to degradation than base metals used. The effect of filler materials on the hot corrosion is discussed. The studies reported in this paper would be beneficial for fabricators embracing this type of dissimilar weldments in the petrochemical and power generation industries.

Journal	Data powered by TypesetMaterials & Design
Publisher	Data powered by TypesetElsevier BV
ISSN	0261-3069
Open Access	No