Title of Invention	AN IMPROVED TECHNIQUE FOR COLD WIRE ADDITION THROUGH AN IMPROVED FEEDER IN SUBMERGED ARC WELDING PROCESS
Abstract	The present invention provides a new configuration of the wire feeder which can simultaneously use multi wires in two different nozzles at different feed rates for different current rating. This new wire feeder substantially enhances the production rate compared to the conventional submerged arc welding process. An integral shaft is designed and interfaced with the existing DC wire feeder for coupling the additional wire feeder for feeding the cold wire in the arc cavity in SAW process. With this new wire feeder the cold wire addition can be provided in both direction of welding. This results additional weld deposit with same heat in-put energy available in the arc zone. Additional power source and control means is not required for this new wire feeder. This new wire feeder is easily interfaceable with the existing SAW machine. With new cold wire system, the results of radiographic test, Ultrasonic test for the test plate are found satisfactory as per code IBR and ASME Sec IX. The present invention is directed to a further development that the dissimilar wire combination is fed using a single wire feeder with two nozzles drawing power from a single power source with parameters of 425 A, 28 V and 0.5 m/min as welding speed. The present invention creates a single weld pool in which the required weld chemistry can be obtained from the use of two wires of different chemistry. This results savings in consumables cost, cycle time reduction and high productivity. The improved cold-wire feeding device of the invention has a plurality of welding wires electrically coupled to a source of electrical energy. Welding wires of different chemistry are being fed in a single wire feeder with two nozzle drawing power from single power source. A common weld pool is created in which the flux is analytically neutral. The weld metal structure is produced with a high proportion of acicular/martensetic structure. The surface proportions of acicular / martensetic is 100 percent. According to the invention, a single pass welding is performed, and buffering layer of welding and machining is avoided. Preferably, a multi layer pass welding is performed for reducing the number of layers compared to the conventional SAW process to enhance the mechanical properties.

Title of Invention

AN IMPROVED TECHNIQUE FOR COLD WIRE ADDITION THROUGH AN IMPROVED FEEDER IN SUBMERGED ARC WELDING PROCESS

Abstract

The present invention provides a new configuration of the wire feeder which can simultaneously use multi wires in two different nozzles at different feed rates for different current rating. This new wire feeder substantially enhances the production rate compared to the conventional submerged arc welding process. An integral shaft is designed and interfaced with the existing DC wire feeder for coupling the additional wire feeder for feeding the cold wire in the arc cavity in SAW process. With this new wire feeder the cold wire addition can be provided in both direction of welding. This results additional weld deposit with same heat in-put energy available in the arc zone. Additional power source and control means is not required for this new wire feeder. This new wire feeder is easily interfaceable with the existing SAW machine. With new cold wire system, the results of radiographic test, Ultrasonic test for the test plate are found satisfactory as per code IBR and ASME Sec IX. The present invention is directed to a further development that the dissimilar wire combination is fed using a single wire feeder with two nozzles drawing power from a single power source with parameters of 425 A, 28 V and 0.5 m/min as welding speed. The present invention creates a single weld pool in which the required weld chemistry can be obtained from the use of two wires of different chemistry. This results savings in consumables cost, cycle time reduction and high productivity. The improved cold-wire feeding device of the invention has a plurality of welding wires electrically coupled to a source of electrical energy. Welding wires of different chemistry are being fed in a single wire feeder with two nozzle drawing power from single power source. A common weld pool is created in which the flux is analytically neutral. The weld metal structure is produced with a high proportion of acicular/martensetic structure. The surface proportions of acicular / martensetic is 100 percent. According to the invention, a single pass welding is performed, and buffering layer of welding and machining is avoided. Preferably, a multi layer pass welding is performed for reducing the number of layers compared to the conventional SAW process to enhance the mechanical properties.

Full Text	FIELD OF THE INVENTION The invention relates to a design and development for making cold wire feeder for butt joint / hardfacing of different combination of filler wires using single/twin/tandem wire submerged arc welding applications. More particularly, the present invention relates to an improved cold wire feeding device in a submerged arc welding system. The invention further relates to an improved process for pressure vessels joints and hard facing of stainless steel fillers of dissimilar chemistry. BACKGROUND OF THE INVENTION The existing cold wire addition process is essentially characterized by the use of one additional wire feeder without any power source which is interfaced with the existing wire feeder with a control means for controlling the overall wire feed rate. In a single wire feeder, along with the main wires, the cold wires are fed simultaneously. The wires in the contact nozzles are arranged tangential to the welding direction. In conventional SAW process, the heat energy is distributed -3- in such way that only 20-25% of the energy is used for melting the filler wire, the rest being utilized in melting the flux including super heating of the molten weld pool and melting the parent plate. It is therefore a high dilution process with approximately twice as much of the plates are being melted as wire. The cold wire addition is one of the advanced technique to make use of excess energy available in the arc cavity for addition of filler material in the form of wire. With addition of cold wire, the excess heat energy is used efficiently for melting the wire. The addition of "cold wire" In the arc stream can increase the deposition rate. Thus, the addition of cold wire can ensure increased transfer efficiency compared to other existing methods. Although, cold-wire addition process results in a highest usable melting rate for a given arc energy, but it simultaneously produces unwanted heat which causes heavy penetration, unfavorable microstructures, high shrinkages and distortion. Nevertheless, the cold wire addition technique results in 40% increase in deposition rate including achieving of better mechanical properties over conventional single / Tandem submerged arc welding process. In current practice, for addition of cold wire, one additional wire feeder is required to be Interfaced along with main wire feeder with a control means to attain the required chemistry and mechanical properties. -4- US patent 4,572,936 describes a submerged arc multiple wire welding system in which only one or two of the welding wires used, are microalloyed wires. The other wires are commercially available unalloyed or low-alloyed solid wires. The process produces a weld metal which has unexpectedly high toughness values, and can be performed more economically. This multiple wire welding system is used in single or multiple-pass welding operations. The system of the US patent is a multiple wire system, in which the wires are fed separately using different power sources and different wire feeders as mentioned in the Examples 1 to 4 of the US patent. OBJECTS OF THE INVENTION It is therefore, an object of the present Invention to propose an improved cold wire feeding device for pressure vessel joints for drum welding using the single tandem wire submerged arc welding which reduces the cycle time and consumption of consumables. Another object of the present invention is to propose an improved cold wire feeding device for hard facing of stainless steels filler of dissimilar chemistry using one of the single-tandem and twin-tandem wire submerged arc welding process which reduces the cycle time and consumption of consumables. -5- A further object of the invention is to propose an Improved process for pressure vessel joints and hard facing of stainless steel fillers of dissimilar chemistry submerged arc welding system. SUMMARY OF THE INVENTION The present invention provides a new configuration of the wire feeder which can simultaneously use multi wires in two different nozzles at different feed rates for different current rating. This new wire feeder substantially enhances the production rate compared to the conventional submerged arc welding process. An integral shaft is designed and interfaced with the existing DC wire feeder for coupling the additional wire feeder for feeding the cold wire in the arc cavity in SAW process. With this new wire feeder the cold wire addition can be provided in both direction of welding. This results additional weld deposit with same heat in-put energy available in the arc zone. Additional power source and control means is not required for this new wire feeder. This new wire feeder is easily interfaceable with the -6- exfsting SAW machine. With new cold wire system, the results of radiographic test, Ultrasonic test for the test plate are found satisfactory as per code IBR and ASME Sec IX. The present invention is directed to a further development that the dissimilar wire combination is fed using a single wire feeder with two nozzles drawing power from a single power source with parameters of 425 A, 28 V and 0.5 m/min as welding speed. The present invention creates a single weld pool in which the required weld chemistry can be obtained from the use of two wires of different chemistry. This results savings in consumables cost, cycle time reduction and high productivity. The improved cold-wire feeding device of the invention has a plurality of welding wires electrically coupled to a source of electrical energy. Welding wires of different chemistry are being fed in a single wire feeder with two nozzle drawing power from single power source. A common weld pool is created in which the flux is analytically neutral. -7- The weld metal structure is produced with a high proportion of acicular/martensetic structure. The surface proportions of acicular / martensetic is 100 percent. According to the invention, a single pass welding is performed, and buffering layer of welding and machining is avoided. Preferably, a multi layer pass welding is performed for reducing the number of layers compared to the conventional SAW process to enhance the mechanical properties. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING Fig. 1 is a prospective view of a cold wire feeding device for single / Tandem submerged arc welding technique for butt welding of drum or for hardfacing of valves wedges according to the present invention. ill DETAILED DESCRIPTION OF THE INVENTION The improved cold-wire feeding device can be adapted to conventional submerged arc welding machine. The invention makes It possible to effectively use different composition of filler materials (1) and weld metal combination. As shown In Fig. 1, the existing cold wire feeder (2) is modified by providing an integral shaft (3). The dissimilar wire combination is fed using the single wire feeder (2,3) with two nozzles (4) drawing power from a single power source (6) with parameters of 425 A, 28 V and 0.5 m/min as the welding speed. A single weid pool (5) Is created in which the required weld chemistry is obtained from the use of two wires (1) of different chemistry. In this technique, to attain the required hardness properties including the required microstructure of the weld metal, the technique of wire feeding in single/ Tandem submerged arc welding creates the common arc pool (5). In the arc cavity, the cold wire fillers (1) with different chemical composition of different alloy wires are fed simultaneously in the two nozzle (4) as shown in Fig 1. i.e., one after another which creates the common weld pool (5) to give the desired weld properties. -9- The invention further enables welding / surfacing to be carried out in grooves having a width of different sizes. The new cold wire feeder (2,3) can be used for welding of drum butt joints, hardfacing of valves wedges and seat rings of different sizes. The invention can be carrled-out under manual and mechanized mode. The invention achieves savings in consumables cost, cycle time reduction and higher productivity. -10- WE CLAIM: 1. An improved process for pressure vessel joints and hard facing of stainless steel fillers of dissimilar chemistry in a submerged arc welding system, the process comprising the steps of: - forming means for feeding additional cold wire, the means being formed by modifying the existing wire feeder in the welding system, the modification being incorporated by interfacing an integral shaft such that the additional cold wire can be fed in both direction of welding; - feeding two dissimilar wire combination one after the another via the single wire feeder using two different nozzles, the two different nozzles drawing power from a single power source (6); and -11 - creating a common weld pool which produces a weld metal structure with high proportion of a acicular/martensetic structure. 2. The process as claimed claim 1, wherein the two nozzles draw power from the single power source with parameters of 400 to 450 Amp, 25 to 30 volt, and welding speed of 0.3 to 0.6 m / minute. 3. The process as claimed in claim 1, wherein the flux created in the common pool is analytically neutral. 4. The process as claimed in claim 1, wherein the surface proportions of acicular /martensetic is 100 percent. 5. The process as claimed in any of the preceding claims, wherein a single pass welding is performed. 6. The process as claimed In claim 1 or 5, wherein a multl layer pass welding is performed to reduce the number of layers which enhances the mechanical properties of the joint. -12- 7. An improved cold wire feeding device in a submerged arc welding system, comprising: - a modified cold wire feeding means which incorporates an integrated shaft (3) on the existing cold wire feeder (2); - at (east two nozzles (4,4) drawing power from a single power source (6) with predetermined operating parameters; and - a single common weld pool (5) created by feeding dissimilar wire combination via the modified cold wire feeding means simultaneously in the at least two nozzles (4). The present invention provides a new configuration of the wire feeder which can simultaneously use multi wires in two different nozzles at different feed rates for different current rating. This new wire feeder substantially enhances the production rate compared to the conventional submerged arc welding process. An integral shaft is designed and interfaced with the existing DC wire feeder for coupling the additional wire feeder for feeding the cold wire in the arc cavity in SAW process. With this new wire feeder the cold wire addition can be provided in both direction of welding. This results additional weld deposit with same heat in-put energy available in the arc zone. Additional power source and control means is not required for this new wire feeder. This new wire feeder is easily interfaceable with the existing SAW machine. With new cold wire system, the results of radiographic test, Ultrasonic test for the test plate are found satisfactory as per code IBR and ASME Sec IX. The present invention is directed to a further development that the dissimilar wire combination is fed using a single wire feeder with two nozzles drawing power from a single power source with parameters of 425 A, 28 V and 0.5 m/min as welding speed. The present invention creates a single weld pool in which the required weld chemistry can be obtained from the use of two wires of different chemistry. This results savings in consumables cost, cycle time reduction and high productivity. The improved cold-wire feeding device of the invention has a plurality of welding wires electrically coupled to a source of electrical energy. Welding wires of different chemistry are being fed in a single wire feeder with two nozzle drawing power from single power source. A common weld pool is created in which the flux is analytically neutral. The weld metal structure is produced with a high proportion of acicular/martensetic structure. The surface proportions of acicular / martensetic is 100 percent. According to the invention, a single pass welding is performed, and buffering layer of welding and machining is avoided. Preferably, a multi layer pass welding is performed for reducing the number of layers compared to the conventional SAW process to enhance the mechanical properties.

Full Text

FIELD OF THE INVENTION
The invention relates to a design and development for making cold wire feeder for butt joint / hardfacing of different combination of filler wires using single/twin/tandem wire submerged arc welding applications. More particularly, the present invention relates to an improved cold wire feeding device in a submerged arc welding system. The invention further relates to an improved process for pressure vessels joints and hard facing of stainless steel fillers of dissimilar chemistry.
BACKGROUND OF THE INVENTION
The existing cold wire addition process is essentially characterized by the use of one additional wire feeder without any power source which is interfaced with the existing wire feeder with a control means for controlling the overall wire feed rate. In a single wire feeder, along with the main wires, the cold wires are fed simultaneously. The wires in the contact nozzles are arranged tangential to the welding direction. In conventional SAW process, the heat energy is distributed

-3-
in such way that only 20-25% of the energy is used for melting the filler wire, the rest being utilized in melting the flux including super heating of the molten weld pool and melting the parent plate. It is therefore a high dilution process with approximately twice as much of the plates are being melted as wire. The cold wire addition is one of the advanced technique to make use of excess energy available in the arc cavity for addition of filler material in the form of wire. With addition of cold wire, the excess heat energy is used efficiently for melting the wire. The addition of "cold wire" In the arc stream can increase the deposition rate. Thus, the addition of cold wire can ensure increased transfer efficiency compared to other existing methods. Although, cold-wire addition process results in a highest usable melting rate for a given arc energy, but it simultaneously produces unwanted heat which causes heavy penetration, unfavorable microstructures, high shrinkages and distortion. Nevertheless, the cold wire addition technique results in 40% increase in deposition rate including achieving of better mechanical properties over conventional single / Tandem submerged arc welding process. In current practice, for addition of cold wire, one additional wire feeder is required to be Interfaced along with main wire feeder with a control means to attain the required chemistry and mechanical properties.

-4-
US patent 4,572,936 describes a submerged arc multiple wire welding system in which only one or two of the welding wires used, are microalloyed wires. The other wires are commercially available unalloyed or low-alloyed solid wires. The process produces a weld metal which has unexpectedly high toughness values, and can be performed more economically. This multiple wire welding system is used in single or multiple-pass welding operations. The system of the US patent is a multiple wire system, in which the wires are fed separately using different power sources and different wire feeders as mentioned in the Examples 1 to 4 of the US patent.
OBJECTS OF THE INVENTION
It is therefore, an object of the present Invention to propose an improved cold wire feeding device for pressure vessel joints for drum welding using the single tandem wire submerged arc welding which reduces the cycle time and consumption of consumables.
Another object of the present invention is to propose an improved cold wire feeding device for hard facing of stainless steels filler of dissimilar chemistry using one of the single-tandem and twin-tandem wire submerged arc welding process which reduces the cycle time and consumption of consumables.

-5-
A further object of the invention is to propose an Improved process for pressure vessel joints and hard facing of stainless steel fillers of dissimilar chemistry submerged arc welding system.
SUMMARY OF THE INVENTION
The present invention provides a new configuration of the wire feeder which can simultaneously use multi wires in two different nozzles at different feed rates for different current rating. This new wire feeder substantially enhances the production rate compared to the conventional submerged arc welding process. An integral shaft is designed and interfaced with the existing DC wire feeder for coupling the additional wire feeder for feeding the cold wire in the arc cavity in SAW process. With this new wire feeder the cold wire addition can be provided in both direction of welding. This results additional weld deposit with same heat in-put energy available in the arc zone. Additional power source and control means is not required for this new wire feeder. This new wire feeder is easily interfaceable with the

-6-
exfsting SAW machine. With new cold wire system, the results of radiographic test, Ultrasonic test for the test plate are found satisfactory as per code IBR and ASME Sec IX.
The present invention is directed to a further development that the dissimilar wire combination is fed using a single wire feeder with two nozzles drawing power from a single power source with parameters of 425 A, 28 V and 0.5 m/min as welding speed. The present invention creates a single weld pool in which the required weld chemistry can be obtained from the use of two wires of different chemistry. This results savings in consumables cost, cycle time reduction and high productivity.
The improved cold-wire feeding device of the invention has a plurality of welding wires electrically coupled to a source of electrical energy. Welding wires of different chemistry are being fed in a single wire feeder with two nozzle drawing power from single power source.
A common weld pool is created in which the flux is analytically neutral.

-7-
The weld metal structure is produced with a high proportion of acicular/martensetic structure.
The surface proportions of acicular / martensetic is 100 percent.
According to the invention, a single pass welding is performed, and buffering layer of welding and machining is avoided. Preferably, a multi layer pass welding is performed for reducing the number of layers compared to the conventional SAW process to enhance the mechanical properties.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Fig. 1 is a prospective view of a cold wire feeding device for single / Tandem submerged arc welding technique for butt welding of drum or for hardfacing of valves wedges according to the present invention.

ill
DETAILED DESCRIPTION OF THE INVENTION
The improved cold-wire feeding device can be adapted to conventional submerged arc welding machine. The invention makes It possible to effectively use different composition of filler materials (1) and weld metal combination. As shown In Fig. 1, the existing cold wire feeder (2) is modified by providing an integral shaft (3). The dissimilar wire combination is fed using the single wire feeder (2,3) with two nozzles (4) drawing power from a single power source (6) with parameters of 425 A, 28 V and 0.5 m/min as the welding speed. A single weid pool (5) Is created in which the required weld chemistry is obtained from the use of two wires (1) of different chemistry. In this technique, to attain the required hardness properties including the required microstructure of the weld metal, the technique of wire feeding in single/ Tandem submerged arc welding creates the common arc pool (5). In the arc cavity, the cold wire fillers (1) with different chemical composition of different alloy wires are fed simultaneously in the two nozzle (4) as shown in Fig 1. i.e., one after another which creates the common weld pool (5) to give the desired weld properties.

-9-
The invention further enables welding / surfacing to be carried out in grooves having a width of different sizes. The new cold wire feeder (2,3) can be used for welding of drum butt joints, hardfacing of valves wedges and seat rings of different sizes. The invention can be carrled-out under manual and mechanized mode. The invention achieves savings in consumables cost, cycle time reduction and higher productivity.

-10-
WE CLAIM:
1. An improved process for pressure vessel joints and hard facing of stainless steel fillers of dissimilar chemistry in a submerged arc welding system, the process comprising the steps of:
- forming means for feeding additional cold wire, the
means being formed by modifying the existing wire
feeder in the welding system, the modification being
incorporated by interfacing an integral shaft such that the
additional cold wire can be fed in both direction of
welding;
- feeding two dissimilar wire combination one after the
another via the single wire feeder using two different
nozzles, the two different nozzles drawing power from a
single power source (6); and

-11
- creating a common weld pool which produces a weld metal structure with high proportion of a acicular/martensetic structure.
2. The process as claimed claim 1, wherein the two nozzles draw
power from the single power source with parameters of 400 to
450 Amp, 25 to 30 volt, and welding speed of 0.3 to 0.6 m /
minute.
3. The process as claimed in claim 1, wherein the flux created in
the common pool is analytically neutral.
4. The process as claimed in claim 1, wherein the surface
proportions of acicular /martensetic is 100 percent.
5. The process as claimed in any of the preceding claims, wherein
a single pass welding is performed.
6. The process as claimed In claim 1 or 5, wherein a multl layer
pass welding is performed to reduce the number of layers
which enhances the mechanical properties of the joint.

-12-
7. An improved cold wire feeding device in a submerged arc welding system, comprising:
- a modified cold wire feeding means which incorporates an
integrated shaft (3) on the existing cold wire feeder (2);
- at (east two nozzles (4,4) drawing power from a single
power source (6) with predetermined operating
parameters; and
- a single common weld pool (5) created by feeding dissimilar wire combination via the modified cold wire feeding means simultaneously in the at least two nozzles
(4).

The present invention provides a new configuration of the wire feeder which can simultaneously use multi wires in two different nozzles at different feed rates for different current rating. This new wire feeder substantially enhances the production rate compared to the conventional submerged arc welding process. An integral shaft is designed and interfaced with the existing DC wire feeder for coupling the additional wire feeder for feeding the cold wire in the arc cavity in SAW process. With this new wire feeder the cold wire addition can be provided in both direction of welding. This results additional weld deposit with same heat in-put energy available in the arc zone. Additional power source and control means is not required for this new wire feeder. This new wire feeder is easily interfaceable with the

existing SAW machine. With new cold wire system, the results of radiographic test, Ultrasonic test for the test plate are found satisfactory as per code IBR and ASME Sec IX.
The present invention is directed to a further development that the dissimilar wire combination is fed using a single wire feeder with two nozzles drawing power from a single power source with parameters of 425 A, 28 V and 0.5 m/min as welding speed. The present invention creates a single weld pool in which the required weld chemistry can be obtained from the use of two wires of different chemistry. This results savings in consumables cost, cycle time reduction and high productivity.
The improved cold-wire feeding device of the invention has a plurality of welding wires electrically coupled to a source of electrical energy. Welding wires of different chemistry are being fed in a single wire feeder with two nozzle drawing power from single power source.
A common weld pool is created in which the flux is analytically neutral.

The weld metal structure is produced with a high proportion of acicular/martensetic structure.
The surface proportions of acicular / martensetic is 100 percent.
According to the invention, a single pass welding is performed, and buffering layer of welding and machining is avoided. Preferably, a multi layer pass welding is performed for reducing the number of layers compared to the conventional SAW process to enhance the mechanical properties.

Documents:

00171-kol-2007-correspondence-1.1.pdf

00171-kol-2007-form-18.pdf

0171-kol-2007-abstract.pdf

0171-kol-2007-assignment.pdf

0171-kol-2007-claims.pdf

0171-kol-2007-correspondence others.pdf

0171-kol-2007-description (complete).pdf

0171-kol-2007-drawings.pdf

0171-kol-2007-form1.pdf

0171-kol-2007-form2.pdf

0171-kol-2007-form3.pdf

171-KOL-2007-(30-01-2012)-ABSTRACT.pdf

171-KOL-2007-(30-01-2012)-AMANDED PAGES.pdf

171-KOL-2007-(30-01-2012)-DESCRIPTION (COMPLETE).pdf

171-KOL-2007-(30-01-2012)-DRAWINGS.pdf

171-KOL-2007-(30-01-2012)-EXAMINATION REPORT REPLY RECIEVED.pdf

171-KOL-2007-(30-01-2012)-FORM 1.pdf

171-KOL-2007-(30-01-2012)-FORM 2.pdf

171-KOL-2007-(30-01-2012)-OTHERS.pdf

171-KOL-2007-(30-01-2012)-PA.pdf

171-KOL-2007-CORRESPONDENCE 1.1.pdf

171-KOL-2007-EXAMINATION REPORT.pdf

171-KOL-2007-FORM 18.pdf

171-KOL-2007-FORM 3.pdf

171-KOL-2007-GPA.pdf

171-KOL-2007-GRANTED-ABSTRACT.pdf

171-KOL-2007-GRANTED-CLAIMS.pdf

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

171-KOL-2007-GRANTED-DRAWINGS.pdf

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

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

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

171-KOL-2007-GRANTED-SPECIFICATION.pdf

171-KOL-2007-OTHERS.pdf

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

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Patent Number

252978

Indian Patent Application Number

171/KOL/2007

PG Journal Number

24/2012

Publication Date

15-Jun-2012

Grant Date

12-Jun-2012

Date of Filing

05-Feb-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	MANNAR SAMY RAMAKRISHNAN	WELDING RESEARCH INSTITUTE BHARAT HEAVY ELECTRICALS LIMITED TIRUCHIRAPPALLI-620 014
2	KRISHNA SAMY PADMANABAN	Welding Research Institute Bharat Heavy Electricals Limited Tiruchirappalli-620014

PCT International Classification Number

B23K35/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA