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.

Rajyalakshmi G

Department of Manufacturing Engineering

School of Mechanical Engineering

Vellore Campus

Yelamasetti B

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 Today: Proceedings

Welding residual stresses can predominantly damage the reliability and performance of the welded structures. In this experimental study the effect of constant and pulse arc TIG welding processes, the development of thermal fields and residual stresses in dissimilar weldments of SS 316 and Monel 400 are investigated. During the welding process, the temperature distribution over the surface of the weldments has been captured using Infra-Red Thermography. The developed residual stresses have been measured experimentally by using the x-ray diffraction technique. The nature of residual stresses in constant and pulse arc weldments have been observed and compared. The experimental results of constant current weldments are validated against finite element analysis using ANSYS software. Transient thermal analysis is performed to determine heat dissipation during the welding process in different modes such as conduction, convection and radiation. Also, the elemental birth and death techniques are considered for the effect of filler wire owing simulation. From the results, the experimental and numerical analysis of constant arc welding process show good agreement to each other in temperature fields and residual stresses. © 2019 IOP Publishing Ltd.

Materials Research Express

Thermal fields and residual stresses analysis in TIG weldments of SS 316 and Monel 400 by numerical simulation and experimentation

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

PCGTAW the heat required to melt the base material is supplied only during the peak current pulses allowing the heat to dissipate into the base material. In the present investigation, an attempt has been made to multipass weld the Inconel to Inconel material using the PCGTAW; ERNiCrMo-3 filler wire is used for the experimentation. The investigation involves metallurgical and mechanical properties of pulsed current gas tungsten arc welding onInconel 600. In this work, an attempt has been made to investigate the double v-grooved weldability; metallurgical and mechanical properties of the PCGTA welded with Inconel 600 similar materials, mechanical property relationships of Inconel 600 weldments are discussed in detail.

Multipass Welding On Inconel Material with Pulsed Current Gas Tungsten Arc Welding

Segregation of Mo is one of the most detrimental problems associated with the welding of super-austenitic stainless steels. The present study articulates the effects of fillers on the microstructure and mechanical properties of pulsed current gas tungsten arc (PCGTA) welded joints of AISI 904L. Four different fillers namely ERNiCrMo-4, ERNiCrMo-10, ERNiCrMo-14 and ERNiCu-7 were employed for joining 5 mm thick plates of AISI 904L. Efforts had been taken to investigate the effect of filler wires on the segregation of Mo in the fusion zone. Studies attested to the retention of Mo in the dendritic regions while employing Ni-Mo rich fillers. Evidently, Mo in the fusion zones was comparatively greater than that in the parent metal. Microstructure studies revealed the formation of unmixed zones at the weld interface while employing these fillers. Migrated grain boundaries were prominent in the fusion zone of ERNiCu-7 weldments. Tensile studies demonstrated that failures occurred at the parent metal of AISI 904L irrespective of fillers employed. Charpy V-notch studies showed that the impact toughness at the cap zones of the weldments was superior to the root regions for all the cases of the weldments. Also, the welded coupons were subjected to cyclic hot corrosion studies at 650 °C in a synthetic molten salt mixture containing K2SO4 + 60% NaCl for 50 cycles. The corrosion studies attested that the fusion zone employing ERNiCrMo-14 exhibited better corrosion resistance than the other fillers and also the parent metal employed in the study. Surface analytical techniques were employed to investigate the hot corroded species. © 2016 The Society of Manufacturing Engineers

Journal of Manufacturing Processes

Effects of filler metals on the segregation, mechanical properties and hot corrosion behaviour of pulsed current gas tungsten arc welded super-austenitic stainless steel

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.

Journal	Data powered by TypesetMaterials Today: Proceedings
Publisher	Data powered by TypesetElsevier BV
ISSN	2214-7853
Open Access	No