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Badheka, Vishvesh J.
- Hybrid Welding of SA516 Gr70 Carbon Steel Material Using Solid and Cored Wires
Authors
1 School of Technology, PDPU, Gandhinagar, Gujarat-382007, IN
2 Mechanical Engineering Department, School of Technology, Pandit Deendayal Petroleum University (PDPU), Gandhinagar, Gujarat-382007, IN
Source
Indian Welding Journal, Vol 49, No 4 (2016), Pagination: 46-46Abstract
Researchers are working on hybrid welds, means application of two different processes one after another. Hybrid weld applications using non consumable arc welding processes, such as Gas Tungsten Arc Welding (GTAW), Plasma Arc welding (PAW) and combination of both mean PAW for the ischolar_main run and GTAW for the filler and cap passes. Conventionally ischolar_main run is filled with the GTAW process because of the excellent weld metal properties and subsequent filler passes with SMAW, SAW or GMAW processes, depending on the size and nature of the job. In the present investigation hybrid concept has been applied to consumable arc welding processes like GMAW, FCAW&MCAW. Metal cored wires 30-35 % costlier than solid wire. Especially for heavy section filler metal requirements increases with increase in plate thickness and process become more costly than normal GMAW.
In the present investigation, 10 mm thick SA516Gr70 steel plate welded using three different consumables includes solid wire (ER70S-6), flux cored wire (E71T-1C) and metal cored wire (E70C-6M) of 1.2mm in size. To weld 10 mm thick plate at 60 degree V-groove, it required two passes, one at the ischolar_main and followed by filler pass. Carbon steel plate SA516Gr70 welded under different hybrid modes combinations. Effect of different hybrid welds welded with solid wire, flux cored and metal cored wire consumables on mechanical and metallurgical properties has been studied, keeping welding variable constant. It was found that hybrid combinations of solid and flux cored wire yield better mechanical properties compared to solid-solid and solid-metal cored wire.
Keywords
GMAW, FCAW, MCAW, Mechanical and Metallurgical Testing.
- Activated Flux TIG Welding Process with Filler Wire
Authors
1 Mechanical Engineering Dept, School of Technology, Pandit Deendayal Petroleum University (PDPU), Gandhinagar-382007, IN
Source
Indian Welding Journal, Vol 49, No 4 (2016), Pagination: 47-47Abstract
An activated flux TIG welding process was developed in 1960s for welding of Titanium by researcher of the Paton Institute of Electric Welding in Ukraine. This process overcomes the major limitation of the conventional TIG welding process, such as its relative shallow penetration particularly in single pass welding operation, high sensibility of the weld bead shape to variation of chemical composition of the base metal and low productivity.
Application of ATIG welding process reported for various ferrous and non ferrous materials including P9, P91, Stainless Steel, Al alloys etc. Many researchers have tried single component fluxes while few tried commercially available fluxes. In fact application of activated flux was reported for various arc welding processes includes PAW, GMAW addition to TIG welding. Limited research report in which flux was applied for LBW and EBW processes also. Recently author reported application A-TIG welding process for joining dissimilar metals, carbon steel to stainless steel.
One of the typical problems faced by A-TIG welding is under fill, which is not acceptable for many critical applications like pressure vessels, cryogenic tanks etc, was solved with application of A-TIG process with filler wire addition. Mechanical properties results are better than normal TIG and A-TIG without filler metal processes.
Keywords
A-TIG Welding, Stainless Steel, Activated Flux, under Fill, Cryogenic Tanks.- Effect of Tool Pin Offset on Mechanical and Metallurgical Properties of Dissimilar FSW Joints of 6061t6 AL Alloy to Copper Material
Authors
1 Mechanical Engg., M. G. M's COE, Nanded, Maharashtra, IN
2 Mechanical Engineering Dept., School of Technology, PDPU, Gandhinagar-7, Gujarat, IN
Source
Indian Welding Journal, Vol 47, No 3 (2014), Pagination: 1-7Abstract
In the present investigation effect of tool pin offset on mechanical and metallurgical properties of dissimilar FSW joints of 6061T6 Al alloy and Copper material was studied. Keeping other FSW variables constant, tool pin offset was varied from 1mm, 2mm and 3mm.The plunge load value decreases with increase in tool pin offset, because of the tool pin is immersed into soft material (Al), while at lower pin offset the plunge load increased.
Tensile Strength (TS) values decreases with increase the tool pin offset. Poor tensile properties were obtained at the very large pin offsets, due to the insufficient reaction between the Cu and Al material. Sufficient reaction was achieved in the FSW Al-Cu joints produced at pin offsets of 1mm and 2mm, resulting in the good tensile properties.
The distribution, amount and size of Cu particles strongly depend on tool pin offset. It is observed that content of dispersed particles decreases at larger tool pin offset. When the pin offset was larger, only few Cu pieces with relatively small size were scratched from the Cu bulk. It was easy for the small Cu pieces to mix into the Al base and react with the Al base in the nugget zone, and therefore no proper mixing of Cu with Al matrix. On the other hand, when the pin offset was smaller, more Al-Cu IMCs would be formed because the more Cu pieces were stirred into the nugget zone. Thus the joining between the Al and Cu became poor due to the brittle nature of the IMCs. Research investigation also highlights the fracture location at different tool pin offsets.
Keywords
Friction Stirs Welding, Aluminum-Copper Dissimilar Materials, Process Parameters, Welding Tool, Butt Joint.- Review on Design and Development of Narrow Gap Welding Torches
Authors
1 Mechanical Engineering Department, School of Technology, Pandit Deendayal Petroleum University, Raisan, Gandhinagar 382 009, IN
2 Fusion Resources, 93/6,Shreeji Ind. Estate, GIDC Makapura, Vadodara, IN
Source
Indian Welding Journal, Vol 45, No 4 (2012), Pagination: 66-76Abstract
Narrow gap welding is an effective process for joining thick plates (2" to 12") of carbon steel, low alloys steel and high strength low alloy steels. But it requires some development in torch design, wire feeding mechanism and welding procedure for preventing all sorts of weld defects before practical application. Narrow gap welding technology is associated with various conventional arc welding technology like GMAW, GTAW, SAW, FCAW&SMAW. Several fabricators world over, especially in Japan have developed their own equipment working on different principles [1]
Standard torches for NGW are not available routinely in the market. Torches for NGW are specially designed (custom made) for various NGW applications. Design of torch will differ from processes to process and application to application. Paper highlights the different torch designs used by researcher for different narrow gap welding technologies like
I) Narrow Gap-Gas Metal Arc Welding (NG-GMAW) Torch Design
II) Narrow Gap-Gas Tungsten Arc Welding (NG-GTAW) Torch Design
III) Narrow Gap- Submerged Arc Welding (NG-SAW) Torch Design.
- Comparative Study of Hot Cracking Susceptibility of AISI 347 Austenitic Stainless Steel (ASS) using Acidic and Basic Coated Filler Material
Authors
1 Metallurgical Engineering Department, The M.S.University of Baroda, IN
2 Fusion Resources, 925/2/8, GIDC Makapura, Vadodara, IN
3 Anup Engineering, Ahmedabad, IN
Source
Indian Welding Journal, Vol 40, No 3 (2007), Pagination: 39-44Abstract
Hot cracking refers to cracking that occurs during welding, casting or hot working at temperatures close to the melting point of the materials. Hot cracking susceptibility of austenitic stainless steel is a problem arising during welding of austenitic stainless steels, particularly in fully austenitic and stabilized compositions. Hot cracking in stainless steel welds is caused by low-melting eutectics containing impurities such as S, P and alloy elements such as Ti, Nb. In stabilized stainless steels, Ti and Nb react with S, N and C to form low melting eutectics. In austenitic stainless steels, segregation plays an overwhelming role in determining cracking susceptibility. Total crack length (TCL), has been used extensively as hot cracking parameter. [1,2]
In the present investigation, an attempt has been made to study hot cracking susceptibility of stabilized ASS on transvarestraint test unit, with acidic and basic coated electrodes.
Experiment, shows that acidic and basic coated electrodes both are more or less equally susceptible to hot.