FIELD OF THE INVENTION

This invention related to the field of submerged arc welding devolopment for
achieving higher productivity and lower dilution.
BACKOROUND 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 arc 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 fl^wn penetration, high deposition rates higher welding speed etc. However
submerged arc welding is characterized by high heat input and consequent higher
dilution. The submerged arc welding process can be made more versatile and
advantageous if the enemy 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 tendem 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, tendem and multi wire welding etc.

need additional heat input for achieving the enchanced 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 ATES 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 eletrode passes through that guides or tips
and makes electrical contacts with each tip. Means are provided to selectively
direct electrical current one of both of the tips. The tip close to the work is
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
rack 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 en object of this invention to propose a method of submarged arc welding to
produce higher deposition rates which eliminates the disadvantages of the prior art.

Another objects of this invention is to propose the use of two electrically connected
contact tubes in serious to produce the preheating of the wire by joule effect thereby
increasing the deposition rate as compared to conventional submerged arc welding.
Furher object of this invention is to reduce the excessive 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 snd repairing of metals and their alloys consisting of a
supplying system of filler wire (1,2,3) with 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 snd is placed just
below the filler wire for welding operation.
The present invention also provides an improved submeerged arc welding process
of joining surfacing and repairing of metals and their alloys consisting of the steps

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.
BRIEF DESCRIPTION OF THE ACCOMPANYING 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.

DESCRIPTION OF THE PREFFERED EMBODIMENT OF THE
INVENTION:
The wire 2 is drawn from the wire spool 1 is fed by 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
this invention, the power supplied by the power source is split 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 free length of the wire
between the contact tip 5 and contact tip 12.Similarly,the power supplied through
the cable 14 and 15 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 length of wire to the passage of the currents through them.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 acheived by increasing the wire feeding speed and this results in higher
deposition rate. A stainless steel bellows or ceramic ferrule bends are used to
shield the length of the wire between the upper contact tube and the power terminal
11.
As an improvement of this technique, a separate power source 22 can be connected
between the power terminal 6 and the job 17. The power source 13 is then

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

WE CLAIM
1. An apparatus with variable wire stickout for submerged arc welding to produce
higher deposition rates and reduced dilution comprising;
a wire spool (1) for feeding continuous coils of wire (2);
a variable speed motor (3) for drawing the wire;
a torch (4) for guiding the wire (2) to the contact tip (5);
characterized in that,
a rack (7) mounted on the torch (4), a pinion (8) mounted on the power
terminal (6) and a knob (9) disposed for moving the said terminal up and
down, carried by the torch, a second contact tip (12) carried by another power
terminal (11) when the two said terminals attached to the two ends of an
insulated block (10) and the power terminals (6 and 11) connected to a
welding power source (13) through cables (14, 15 and 16) while a stainless
steel bellows or ceramic ferrule beads disposed for shielding the length of the
wire between the upper contact tube (5) and the power terminal (11), wherein
the cables (14 and 15) feed the two power terminals with split up portion of
the power for separately heating up the free length of the wire stickout
between the contact tip 5 and contact tip 12 and between contact tip 12 and
the arc (19).

2. An improved apparatus as claimed in claim 1, wherein a separate power source
(22) is connected between the power terminal 6 and the job 17 when the
power source 13 is connected between the power terminal 11 and the job 17
for varying the stickout and heating effect.
3. A method for utilizing an improved submerged arc welding apparatus of claim
1, comprising;
drawing of the wire (2) from the wire spool (1) by a wire feeding motor (3);
feeding the wire (2) to the torch (4) and through the contact tips (5) and (12);
splitting up the power supply into two portions and feeding the two power
terminals (6,11) through cables (14,15);
heating up the free length of the wire through power supply between contact
tip 5 and contact tip 12 and that between contact tip 12 and the arc (19) when
heating reduces quantum of current required for the melting of the wire at the
arc (19) when current is increased to its original value by increasing the wire
feeding speed resulting higher deposition rate.

4. A method as claimed in claim 2, wherein a separate power source 22 is connected
between the power terminals 6 and the job 17 when power source 13 is connected
between power terminal 11 and the job 17 when the heating effect is varied by
varying the stickout and the power supply from the power source 22.

ABSTRACT

AN APPARATUS WITH VARIABLE WIRE STICKOUT FOR SUBMERGED ARC
WELDING TO PRODUCE HIGHER DEPOSITION RATES AND REDUCED
DILUTION AND A METHOD FOR THE SAME.
An apparatus with variable wire stickout for submerged arc welding consists of a wire
spool (1) for feeding continuous coils of wire (2), a variable speed motor (3) for
drawing the wire, and a torch (4) for guiding the wire (2) to the contact tip (5). A rack
mounted on the torch (4), a pinion mounted on the power terminal (6) and a knob (9)
is disposed for moving the said terminal up and down which is carried by the torch. A
second contact tip (12) is carried by another terminal (11) when the two said
terminals are attached to the two ends of an insulated block (10). The power
terminals 6 and 11 are connected to a welding power source (13) through cables 14,
15 and 16. Bellows made up of insulating materials or ceramic ferrule beads are
disposed for shielding the length of the wire between the upper contact tube (5) and
the power terminal (11). The cables (14 and 15) feed the two power terminals with
split up portion of the power for separately heating up the free length of the wire
stickout between the contact tip 5 and contact tip 12 and between contact tip 12 and
the arc 19.