Title of Invention

AN APPARATUS WITH VARIABLE WIRE STICKOUT FOR SUBMERGED ARC WELDING TO PRODUCE HIGHER DEPOSITION RATES AND REDUCED DILUTION AND A METHOD FOR THE SAME

Abstract Submerged arc welding has several advantages like deep penetration, high deposition rates higher welding speed etc. However, submerged arc welding is characterized by high heat input and consequent higher dilution. In joining of metal and their alloys, the main process requirements from productivity point of view are the penetration and deposition rate. In surfacing applications, the process capabilities sought after arc lower dilution and higher deposition rate. Also these applications will benefit if better weld joint and deposit properties can be ensured. The submerged arc welding process can be made more versatile and advantageous if the energy input is better utilized to enhance the deposition rates and lower the penetration achieved, leading to lower dilution percentage.
Full Text 1
FIELD OF THE INVENTION:
This invention related to the field of submerged are welding developments for
achieving higher productivity and lower dilution.
BACKGROUND OF INVENTION:
Welding is used advantageously for joining, surfacing and repair of metals and
their alloys. In joining of metal and their alloys, the main process requirements
from productivity point of view are the penetration and deposition rate. In
surfacing applications, the process capabilities sought after are lower dilution and
higher deposition rate. Also these applications will benefit if better weld joint and
deposit properties can be ensured Submerged arc welding has several advantages
like deep penetration, high deposition rates higher welding speed etc However,
submerged arc welding is characterized by high heat input and consequent higher
dilution. Tzzzze submerged arc welding process can be made more versatile and
advantageous if the energy input is better utilized to enhance the deposition rates
and lower the penetration achieved, leading to lower dilution percentage.
Several technologies have been developed based on submerged arc welding to
improve the deposition rate. These techniques include tandem and hot wire SAW;
multi wire SAW, series arc welding, metal powder addition, cold wire addition etc.
Some of these techniques like hot wire SAW, tandem and multi wire welding etc.

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need additional heat input for achieving the enhanced deposition rates. Other
techniques like cold wire addition, metal powder addition and series arc welding
require extra facilities feeding additional filler metal.
This invention presents a novel method of achieving higher deposition rates while
reducing the percentage dilution of the filler metal deposited.
STATE OF ART:
US. Patent No. 3,590,213. An electrode having a pair of axially spaced electrode
guided for use in arc welding. The electrode passes through these guides or tips
and makes electrical contacts with each tip. Means are provided to selectively
direct electrical current one or both of the ops. The tip dose to the work is
connected to the circuit to provide the current to the eletrode at a point adjacent to
the work piece to initiate the arc. Once the arc is started, the tip is isolated from
the electrical circuit; and the current is provided to the electrode through the tip
remote from the work piece to permit long electrical stick out arc welding Long
stick out for a given current by heat up the electrode to high temperature which
may not be desirable. This may lead to oxidation of the wire surface and
subsequent oxide in the wells metal.
OBJECTS OF INVENTION:
It is an object of this invention to propose a method of submerged arc welding to
produce higher deposition rotes which eliminates the disadvantages of the prior art.

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Another object of this invention is to propose the use of two electrically connected
contact tubes in series to produce the preheating of the wire by joule effect thereby
increasing the deposition rate as compared to conventional submerged arc welding.
Further object of this invention is to reduce the exeessive heating of the wire for a
given length of the long stick out through splitting of the welding current
A still further objective of this invention is to provide a method of controlling the
heating effect by varying the stick out length.
Another objective of this invention is to effectively control the heating effect by
providing an auxiliary power source for heating the wire.
According to the present invention an improved submerged arc welding apparatus
for joining, surfacing and repairing of metals and their alloys consisting of a
supplying system of filler wire (1,2,3) with a torch (4) to guide the wire to the first
contact tip (5); power supply system with two power supply terminals (6\ 11) where
the power terminal (11) carries the second contact tip (12) and the job (17) is
connected to the other terminal of the power supply system and is placed just
below the filler wire for welding operation.
The present invention also provides an improved submerged arc welding process
of joining, surfacing and repairing of metals and their alloys consisting of the steps

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drawing the wire (2) from the spool (1) containing coil of wire by a variable speed
wire feeding motor (3) to feed the torch (4) and the wire thereafter passes through
the two contact tips (5,12) before it melted by the arc created by the power
supplied from the welding power supply system.
DESCRIPTION OF THE DRAWINGS:
The apparatus used for the invention, is described below:
A spool 1 containing the continuous coil of wire 2 is drawn by a variable speed
wire-feeding unit 3. The torch 4 guides the wire 2 to the contact tip 5. The torch
carries a movable terminal 6 which transfers the welding power to the torch. The
power terminal is moved up and down with the help of a rack 7 mounted on the
torch, a pinion 8 mounted on the power terminal and a knob 9. The power terminal
is connected to one end of an insulting block 10. Another power terminal 11 is
mounted at the other end of the insulating block. The power terminal 11 carries
the second contact tip 12. The power terminals 6 and 11 are connected to a
welding power source 13 through cables 14,15 and 16. The job 17 is connected to
the other terminal of the power source 13 through the cable 18. During the
welding process the arc 19 created between the wire and the job 17 under a
shielding medium of flux 20 produces a weld bead 21.

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DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE
INVENTION:
The wire 2 is drawn from the wire spool 1 is fed by a wire feed motor 3 to the
torch 4. The wire passes through the two contact tips 5 and 12 before it is melted
by the arc 19 created by the power supplied form the welding power source 13. In
mis invention, the power supplied by me power source is split into two portions
and fed to the two power terminals in the apparatus through separate cables 14 and
15. The power supplied through cable 14 heats up the tree length of the wire
between the contact tip 5 and contact up 12. Similarly, the power supplied through
the cable 14 and IS heat up the free length of the wire between the contact tip 12
and the arc This heating is due to the joule effect caused by the resistance offered
by the respective lengths of wire to the passage of the currents through mem. This
heating reduces the quantum of current required for the melting of the wire at the
arc at the present wire feed speed. Increasing the current to its original value can
be achieved by increasing the wire feeding speed and mis results in higher
deposition rate. A stainless steel bellows or ceramic ferrule beads are used to
shield the length of the wire between the upper contact tube and the power terminal
11.
As an improvement of mis technique, a separate power source 22 can be connected
between the power terminal 6 and the job 17. The power source 13 is then

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connected between the power terminal 11, and job 17. By varying the stickout and
the power supply from the power source 22, the healing effect can be varied
effectively.

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WE CLAIM:
1. An improved submerged arc welding apparatus for joining, surfacing and
repairing of metals and their alloys using long stick out length of filler wire,
comprising of
a. Filler wire feeding mechanism having spool (I) to feed continuous
coils of wire (2), drawn by a variable speed motor (3) with a torch (4)
to guide the wire to the first contact tip (5).
b. Power supply terminals (6,11) connected to the two ends of an
insulating block (10) keeping the supply terminals electrically
isolated.
c. Power supply system having power source (13), connected to the
power supply terminals (6,11) through the cables (16, 14, and 15) and
other end is connected to the job (17) through the cable (18) and the
arc (19) created between the wire and the job under a shielding
medium of flux (20) producing weld bead (21).
d A rack (7) mounted on the torch (4), a pinion (8) mounted on the
power supply terminal (6) and a knob (9) for upward and downward
movement of the supply terminal (6) to adjust distance between the
two contact tips (5, 12) with the help of the rack and pinion
mechanism.

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e. A separate power source (22) connected between the power terminal
(6) and the job (17) to vary the heating effect effectively.
2. An improved submerged are welding method using the apparatus as claimed
in claim 1 involves the steps of drawing the wire (2) from the spool (1) by a
variable speed wire feeding motor (3) to feed the torch (4) and the wire
thereafter passes through the two contact tips (5, 12) before it melted in the
(arc) (19) created by the power supplied from the welding power supply
system.
3. The method as claimed in claim 2, wherein power supply system (13) has
two portions, one portion is connected to the movable power terminal (6) to
transfer welding power to the torch (4) connected to the first contact tip (5)
and the other portion supplies power to the terminal (11) connected to the
second contact tip (12).
4. The method as claimed in claim 3, wherein the power supplied to the power
terminal (6) heats up the free length of the wire between the contact tips (5)
and (12) and the total power supplied by the power source heats up the free
length of the wire between the contact tip (12) and the arc (19) and the
heating is based on the joule effect caused by the resistance offered by
respective lengths of wire, while this heating reduces the quantum of current

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required for the melting of the wire and the distance between the contact tips
(5,12) is adjusted with the help of rack & pinion device (7,8,9).
5. The method as claimed in claim 2 & 3 wherein a portion of power supplied
to the power terminal (6) is drawn from a separate power source (22) and the
second portion of power supplied to the terminal (11) is drawn from the
power source (13) to vary the heating effect
6. A improved submerged arc welding apparatus for joining, surfacing and
repairing of metals and their alloys substantially as herein described and
illustrated in the accompanying drawing.
7. An improved submerged arc-welding method substantially as herein
described and illustrated in the accompanying drawing.
Dated this 22nd day of march 2007

Submerged arc welding has several advantages like deep penetration, high
deposition rates higher welding speed etc. However, submerged arc welding is
characterized by high heat input and consequent higher dilution. In joining of
metal and their alloys, the main process requirements from productivity point of
view are the penetration and deposition rate. In surfacing applications, the process
capabilities sought after arc lower dilution and higher deposition rate. Also these
applications will benefit if better weld joint and deposit properties can be ensured.
The submerged arc welding process can be made more versatile and advantageous
if the energy input is better utilized to enhance the deposition rates and lower the
penetration achieved, leading to lower dilution percentage.

Documents:

00455-kol-2007-abstract.pdf

00455-kol-2007-claims.pdf

00455-kol-2007-correspondence others 1.1.pdf

00455-kol-2007-corrospond others.pdf

00455-kol-2007-description complete .pdf

00455-kol-2007-drawings.pdf

00455-kol-2007-form 1.pdf

00455-kol-2007-form 18.pdf

00455-kol-2007-form 2.pdf

00455-kol-2007-form 3.pdf

00455-kol-2007-gpa.pdf

455-KOL-2007-(07-09-2011)-ABSTRACT.pdf

455-KOL-2007-(07-09-2011)-AMANDED CLAIMS.pdf

455-KOL-2007-(07-09-2011)-AMENDED PAGES Of SPECIFICATION.pdf

455-KOL-2007-(07-09-2011)-CORRESPONDENCE.pdf

455-KOL-2007-(07-09-2011)-DRAWINGS.pdf

455-KOL-2007-(07-09-2011)-FORM 1.pdf

455-KOL-2007-(07-09-2011)-FORM 2.pdf

455-KOL-2007-(07-09-2011)-FORM 3.pdf

455-KOL-2007-(07-09-2011)-FORM 5.pdf

455-KOL-2007-(07-09-2011)-OTHERS.pdf

455-KOL-2007-(07-09-2011)-PA.pdf

455-KOL-2007-(07-09-2011)-PETITION UNDER RULE 137.pdf

455-KOL-2007-(23-02-2012)-CORRESPONDENCE.pdf

455-KOL-2007-CORRESPONDENCE.pdf

455-KOL-2007-EXAMINATION REPORT.pdf

455-KOL-2007-FORM 3.pdf

455-KOL-2007-FORM 5.pdf

455-KOL-2007-GPA.pdf

455-KOL-2007-GRANTED-ABSTRACT.pdf

455-KOL-2007-GRANTED-CLAIMS.pdf

455-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

455-KOL-2007-GRANTED-DRAWINGS.pdf

455-KOL-2007-GRANTED-FORM 1.pdf

455-KOL-2007-GRANTED-FORM 2.pdf

455-KOL-2007-GRANTED-LETTER PATENT.pdf

455-KOL-2007-GRANTED-SPECIFICATION.pdf

455-KOL-2007-OTHERS.pdf

455-KOL-2007-REPLY TO EXAMINATION REPORT.pdf


Patent Number 253098
Indian Patent Application Number 455/KOL/2007
PG Journal Number 26/2012
Publication Date 29-Jun-2012
Grant Date 25-Jun-2012
Date of Filing 22-Mar-2007
Name of Patentee BHARAT HEAVY ELECTRICALS LIMITED
Applicant Address REGIONAL OPERATIONS DIVISION (ROD), PLOT NO:9/1, DJBLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI-110049
Inventors:
# Inventor's Name Inventor's Address
1 KRISHNASAMY PADMANABAN SDGM, WRI, BHEL, TRICHY-620 014
2 MARIMUTU SAMIDURAI SPE, WRI, BHEL TRICHY-620 014
3 MANNAR SAMY RAMAKRISHNAN MANAGER, WRI, BHEL TRICHY-620 014
PCT International Classification Number B23K9/18
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA