Effect of Tungsten Inert Gas Welding Shielded Metal Arc Welding Processes

on Mechanical Properties of

Super Duplex Stainless Steel(AISI 2507)

College of Engineering, Guindy

STUDENTS ARJUN M 2010118004 MOHAN RAJ N 2010118030 SURYAPRAKASH S 2010118050 RAJESH R 2010118058

GUIDE Dr. K. SHANMUGA SUNDARAM

ASSOCIATE PROFESSORDEPARTMENT OF MECHANICAL ENGINEERING

COLLEGE OF ENGINEERING, GUINDY, ANNA UNIVERSITY CHENNAI 600025

CO-GUIDE Mr. A. VINOTH JEBARAJ

TEACHING RESEARCH ASSITANTDEPARTMENT OF MECHANICAL ENGINEERING

COLLEGE OF ENGINEERING, GUINDY, ANNA UNIVERSITY CHENNAI 600025

AIM OF THE PROJECT

To determine the mechanical properties of Super duplex stainless steel (AISI 2507) during welding processes (Tungsten Inert Gas Welding & Shielded Metal Arc Welding).

To plot the thermal distribution curves in a simulation software using the data acquired with the help of sensors during the welding processes.

SUPER DUPLEX STAINLESS STEEL• Chemical composition of super duplex stainless steel• Chromium : 24 % - 26 %• Carbon : 0.030 % (max)• Nickel : 6 % - 8 %

• Mixture of Austenitic & Ferritic phases• Advantageous properties of both phases are utilized

effectively• Very resistive to extensive environments• Used in marine, chemical, oil & gas, paper & pulp

(extreme environments)• Active research area in mechanical engineering

WORK-FLOW• Procure steel plates • Testing for desired properties

• Optical emission spectrometry • Microstructural testing for phase confirmation

• Edge preparation • Electrode Filler materials • TIG & SMA welding processes

• Non Contact type (Infrared) thermometer to measure temperatures at the welding zone, heat affected zone, base metal

• Microstructural analyses Mechanical testings • Plot thermal distribution curves in a simulation software

using the data acquired during welding processes • Results Discussions

MICROSTRUCTURAL ANALYSIS

Etchant used: Aquaregia (Hydrochloric acid + Sulphuric acid)

Standard: IS. 7739 (Part V) 1976Magnification: 100x

CHEMICAL COMPOSITIONOptical Emission Spectrometry

( Standard: ASTM E1086-94(R-08) Test temperature: 24.5o C )

Elements Observed value Standard requirement

Carbon 0.0280 % 0.030 % maxCopper 0.2700 % 0.500 % max

Chromium 24.0200 % 24 % - 26 %Manganese 1.1000 % 1.20 % max

Molybdenum 3.1700 % 3 % - 5 %Nickel 6.5000 % 6 % - 8 %

Phosphorous 0.0150 % 0.035 % maxSulphur 0.0150 % 0.020 % maxSilicon 0.2950 % 0.800 % max

DIMENSIONS OF THE PLATES

FILLER MATERIAL ELECTRODE

Filler material : Zeron 100UNS S32760 (50-50 austenitic-ferritic)Chromium : 25 %Nickel : 7 %Moleybdenum : 3.6 %

Electrode material : ER2594Chromium : 25.5 %Nickel : 9.2 %Moleybdenum : 3.5 %

TIG-W SMAW PROCESS PHOTOS

MECHANICAL PROPERTIES

BASE METAL(SDSS AISI 2507)

TIG WELDED SDSS SMA WELDED SDSS

Ultimate Tensile Strength (MPa)

799.8 832.76 844.68

Yield Strength (MPa) 591.5 650.79 643.75

Elongation (%) 15 24.1 25.3

Vickers’ Hardness (HV) 310 WELD HAZ BASE WELD HAZ BASE

368.8 334.9 316.5 316.2 295.1 273.8

Impact Energy (J) 100 128 108

COMPARISON OF MECHANICAL PROPERTIES

STRESS-STRAIN CURVE OF TIG-W

SPECIMEN 1

SPECIMEN 2

STRESS-STRAIN CURVE OF SMA-W

SPECIMEN 1

SPECIMEN 2

MICROSTRUCTURE OF TIG-W

WELD ZONE:The microstructure shows acicular ferrite and austenite grains. The percentage of and is

68% 32%

HAZ:The microstructure shows coarser acicular ferrite and austenite grains. The percentage of

and is 65% 35%

BASE:The microstructure shows elongated ferrite-austenite grains. The percentage of and is

62% 38%

MICROSTRUCTURE OF SMA-W

WELD ZONE:The microstructure shows acicular ferrite and austenite grains. The percentage of and is

71% 29%

HAZ:The microstructure shows coarser acicular ferrite and austenite grains. The percentage of

and is 67% 33%

BASE:The microstructure shows elongated ferrite-austenite grains. The percentage of and is

61% 39%

MACROSTRUCTURE OF TIG SMA

TEMPERATURE DISTRIBUTION CURVES – ANSYS SIMULATION

TIG WELDINGSMA WELDING

BIBLIOGRAPHY REFERENCES1. Physical Metallurgy by Sidney H. Avner published by

McGraw-Hill2. Welding Metallurgy by Sindo Kou published by John

Wiley Sons, Inc., publications3. X-ray diffraction residual stress techniques published

by Lambda Research, Inc.