FULLY AUTOMATED PLASMA FULLY AUTOMATED PLASMA TRANSFERRED ARC POWDER TRANSFERRED ARC POWDER DEPOSITION FOR WEAR AND DEPOSITION FOR WEAR AND

CORROSION RESISTANT OVERLAYING CORROSION RESISTANT OVERLAYING NEEDS – AN OVERVIEWNEEDS – AN OVERVIEW

C.BALASUBRAMANIANC.BALASUBRAMANIANOMPLAS SYSTEMSOMPLAS SYSTEMS

About the Plasma About the Plasma Arc……..Arc……..

Plasma is the fourth state of matter, Plasma is the fourth state of matter, namely ions. Gas particles exist in the namely ions. Gas particles exist in the form of ions which conduct electricityform of ions which conduct electricity

We make very effective use of this and We make very effective use of this and hence, called Plasma Arc.hence, called Plasma Arc.

For all practical purposes, this is a For all practical purposes, this is a modified Tungsten arc which is more modified Tungsten arc which is more directive, columnar and stable. This is directive, columnar and stable. This is achieved by constricting the tungsten achieved by constricting the tungsten arc through a water cooled orificearc through a water cooled orifice..

TIG and PLASMA arcTIG and PLASMA arc

TIG PLASMA

Arc shapes in TIG and Arc shapes in TIG and PlasmaPlasma

Advantages of Plasma Arc Advantages of Plasma Arc over TIGover TIG

Highly stable and concentrated arcHighly stable and concentrated arc Heat less affected in the changes in the Heat less affected in the changes in the

arc length- More consistent.arc length- More consistent. Stable at very low welding currentsStable at very low welding currents Very low heat input to the base metal Very low heat input to the base metal

(more concentrated in a small area)(more concentrated in a small area) Flash light effect (with very powerful UV Flash light effect (with very powerful UV

radiation)radiation) Very favorable shape to control the width Very favorable shape to control the width

to penetration ratio.to penetration ratio.

Plasma Arc welding Plasma Arc welding applications……..applications……..

Metal cuttingMetal cutting Welding (key hole square butt welding)Welding (key hole square butt welding) Micro plasma welding (for thin sheets)Micro plasma welding (for thin sheets) Weld overlayingWeld overlaying Plasma heat treatment (plasma Plasma heat treatment (plasma

nitriding, heating)nitriding, heating) Plasma metal sprayingPlasma metal spraying

Weld overlaying – an Weld overlaying – an important tribological important tribological

process…..process….. Cladding of special material on the surface Cladding of special material on the surface

of a component to obtain certain desired of a component to obtain certain desired properties that are not possessed by the properties that are not possessed by the core or the base material itself. Because of core or the base material itself. Because of these special properties, the basic these special properties, the basic component attains higher wear and component attains higher wear and corrosion resistance, which increase the corrosion resistance, which increase the life of the component. In simple words, part life of the component. In simple words, part with inferior base material, along with the with inferior base material, along with the overlay performs better than either of the overlay performs better than either of the two for the given application.two for the given application.

This phenomenon can be at various This phenomenon can be at various operating temperatures (cold or hot)operating temperatures (cold or hot)

Plasma Weld overlaying Plasma Weld overlaying using powdered filler metalusing powdered filler metal

Adding a homogenous powdered super Adding a homogenous powdered super alloy through the plasma arc and deposit alloy through the plasma arc and deposit over a substrate by melting both in a over a substrate by melting both in a controlled manner to obtain an effectively controlled manner to obtain an effectively fused cladding over the substrate.fused cladding over the substrate.

The deposited metal is metallurgical The deposited metal is metallurgical bonded with the base (not just sprayed )bonded with the base (not just sprayed )

Bonding strength is more than the Bonding strength is more than the strength of the base metal in PTAW strength of the base metal in PTAW process.process.

Schematic of the Plasma Schematic of the Plasma weld overlaying torch.weld overlaying torch.

Parameters controls…Parameters controls… PLC programs/ memories PLC programs/ memories Arc link communication systems for Arc link communication systems for

effective co-ordination of modules through effective co-ordination of modules through PCsPCs

User friendly MMI (Man-Machine- User friendly MMI (Man-Machine- Interface)Interface)

Specific PLC/CNC based systems to closely Specific PLC/CNC based systems to closely monitor and control the WPS essential monitor and control the WPS essential variables (welding parameters, weld variables (welding parameters, weld sequencing, varying welding parameters sequencing, varying welding parameters within a layer, etc)within a layer, etc)

Modules of fully automated PTAW Modules of fully automated PTAW overlaying set up.overlaying set up.

Plasma Transferred Arc Power sourcePlasma Transferred Arc Power source Pilot Arc Power sourcePilot Arc Power source Welding Torch Carriage/ Manipulator (C&B)Welding Torch Carriage/ Manipulator (C&B) WeldingWelding Positioner Positioner Welding Torch weaving unit (Oscillator)Welding Torch weaving unit (Oscillator) Plasma welding torchPlasma welding torch X-Y-Z slidesX-Y-Z slides Powder feeding unit/ wire feeding unitPowder feeding unit/ wire feeding unit Gas and control consoleGas and control console Operator’s control panelOperator’s control panel Water cooling unitWater cooling unit AVC unit (optional)AVC unit (optional) Tracking devices (Optional)Tracking devices (Optional) Video /defect Monitors (Optional)Video /defect Monitors (Optional)

CARRIAGE TYPE SYSTEM

COLUMN & BOOM TYPE SYSTEM

Deloro machine – Column & boom Deloro machine – Column & boom typetype

Deloro machine - Lathe Deloro machine - Lathe typetype

Robotic PTAW overlaying Robotic PTAW overlaying systemsystem

Plasma Weld Overlaying Plasma Weld Overlaying torchestorches

Deloro- ID torchDeloro- ID torch

Plasma weld overlaying Plasma weld overlaying torches for internal claddingtorches for internal cladding

PLASMA WELD-OVERLAYING POSSIBLE OVERLAYING OF INNER DIAMETERS OF SLEEVES ABOVE 60MM WITH POWDER

CONSUMMABLES.

PLASMA OVERLAYING IN PROGRESS

PTAW weld overlaying - PTAW weld overlaying - DescriptionDescription

Powdered consumable is introduced in the steady, Powdered consumable is introduced in the steady, constricted columnar plasma transferred arc.constricted columnar plasma transferred arc.

Pilot arc is generated inside the torch which Pilot arc is generated inside the torch which provides the ionization path for the transferred arc.provides the ionization path for the transferred arc.

Argon gas from the cylinder is trifurcated in to Argon gas from the cylinder is trifurcated in to three parts, namely centre (plasma gas), shield three parts, namely centre (plasma gas), shield gas and powder carrier gas. Gas flows are rightly gas and powder carrier gas. Gas flows are rightly chosen to get the right weld bead and chemistry.chosen to get the right weld bead and chemistry.

Job is held in a positioner or turn table and rotated Job is held in a positioner or turn table and rotated at a desirable speed.at a desirable speed.

Powder feeder unit feeds the powder at a desirable Powder feeder unit feeds the powder at a desirable consistent feed rate (typical feed rate is 25 gms to consistent feed rate (typical feed rate is 25 gms to 35 gms per minute).35 gms per minute).

Description continues……….Description continues………. Torch oscillator weaves the torch to get a right bead Torch oscillator weaves the torch to get a right bead

shape (width and height).shape (width and height). Water cooling unit protects the torch by instantly cooling Water cooling unit protects the torch by instantly cooling

the orifice and there by ensuring uninterrupted welding.the orifice and there by ensuring uninterrupted welding. Basic carriage or the manipulator and the X-Y-Z slide are Basic carriage or the manipulator and the X-Y-Z slide are

used to precisely position the torch over the weld zone.used to precisely position the torch over the weld zone. Operator panel provides all the salient controls which are Operator panel provides all the salient controls which are

to be adjusted to get the right weld. It is linked to the to be adjusted to get the right weld. It is linked to the control console which interfaces all the modules.control console which interfaces all the modules.

Welding torch is specially designed for overlaying Welding torch is specially designed for overlaying application and there are various versions to suit various application and there are various versions to suit various applications.applications.

All the variables are set to attain the required melting of All the variables are set to attain the required melting of the base and bead width & height (dilution not exceeding the base and bead width & height (dilution not exceeding 5%)5%)

Alloys deposited …..Alloys deposited …..

All kinds of Cobalt based super alloys (Stellite of All kinds of Cobalt based super alloys (Stellite of various grades. etc.).various grades. etc.).

All kinds of Nickel based super alloys (Ni-Cr-B All kinds of Nickel based super alloys (Ni-Cr-B colmonoys, Inconels, Monels, Hastelloy, Pure colmonoys, Inconels, Monels, Hastelloy, Pure Nickel, etc.)Nickel, etc.)

All kinds of Stainless Steels (austenitic, ferritic All kinds of Stainless Steels (austenitic, ferritic and martensitic) and martensitic)

Triboloy and other Lave Phase alloysTriboloy and other Lave Phase alloys WC with Nickel or Cobalt matrix.WC with Nickel or Cobalt matrix. Chrome carbides in Iron matrixChrome carbides in Iron matrix and much more……..and much more……..

Sizes and shapes of the Sizes and shapes of the components…..components…..

As small as 50 grams to unlimited sizesAs small as 50 grams to unlimited sizes Any regular shapes – CYLINDRICAL Any regular shapes – CYLINDRICAL

SURFACES (RODS, PIPES, RINGS), PLATES SURFACES (RODS, PIPES, RINGS), PLATES OF VARIOUS THICKNESSES, CONICAL OF VARIOUS THICKNESSES, CONICAL SHAPES, SPHERICAL SURFACES, SHAPES, SPHERICAL SURFACES, COMBINATION OF ALL SHAPES.COMBINATION OF ALL SHAPES.

Irregular shapes are effectively handled by Irregular shapes are effectively handled by RobotsRobots

Deposition up to 100 kgs. in a single Deposition up to 100 kgs. in a single component with least interruption.component with least interruption.

Challenges faced in Weld Challenges faced in Weld overlaying……overlaying……

CracksCracks Other weld defects such as Other weld defects such as

porosities, pinholes.porosities, pinholes. Crater shrinkagesCrater shrinkages Lack of fusionLack of fusion Dilution with the base ( Fe% in the Dilution with the base ( Fe% in the

deposit, strictly restricted to 7% deposit, strictly restricted to 7% max.)max.)

DISTORTIONDISTORTION

How these problems are How these problems are effectively tackled in PTAW….effectively tackled in PTAW….

Weld speeds far higher Weld speeds far higher Close adherence to WPS/PQR parameter – Close adherence to WPS/PQR parameter –

machine dependent –Better arc heat controlmachine dependent –Better arc heat control Less welder/Operator influenceLess welder/Operator influence Less fatigue ( less deterrent to following the Less fatigue ( less deterrent to following the

parameters such as pre heating)parameters such as pre heating) High pre heating levels ( up to 650 deg. C) with High pre heating levels ( up to 650 deg. C) with

least operator fatigue.least operator fatigue. Greater uniformity of the temperature Greater uniformity of the temperature

distribution. (dT variations far less)distribution. (dT variations far less) Automation aiding the best sequencing of Automation aiding the best sequencing of

welding- multiple passes with weaving.welding- multiple passes with weaving.

Merits of fully automatic PTA Merits of fully automatic PTA powder deposition process over powder deposition process over

other processes….other processes…. Highly energy density in a stable and focused arc Highly energy density in a stable and focused arc

gives a better controlled and consistent weldment gives a better controlled and consistent weldment with fusion bonding.with fusion bonding.

Long and uninterrupted arcing hours with least Long and uninterrupted arcing hours with least operator fatigue.operator fatigue.

Excellent weld appeal (resulting in low machining Excellent weld appeal (resulting in low machining requirements.)requirements.)

Low and controllable dilution from the base metal Low and controllable dilution from the base metal substrate – Typically 5% without the fear of lck of substrate – Typically 5% without the fear of lck of bonding.bonding.

Less defects ( porosity, crack, LOF, etc.)Less defects ( porosity, crack, LOF, etc.) High deposition rates (high productivity)High deposition rates (high productivity)

Merits continued……Merits continued……

Close and accurate control of deposit Close and accurate control of deposit thickness (thicknesses from 1mm to 6mm thickness (thicknesses from 1mm to 6mm is possible in single layer- best is 3 to 4mm is possible in single layer- best is 3 to 4mm in single layer)in single layer)

Highly versatile for automation because of Highly versatile for automation because of stable arc (hence, becomes a very stable arc (hence, becomes a very effective process on productivity and effective process on productivity and quality parameters).quality parameters).

Good control on alloy chemistry (no Good control on alloy chemistry (no variations in the properties of the deposit) variations in the properties of the deposit) -close control over parameters.-close control over parameters.

Great reproducibility / repeatability Great reproducibility / repeatability

Some applications…..Some applications…..

Let us quickly go through some of Let us quickly go through some of the applications which have been the applications which have been effectively cladded using this effectively cladded using this process.process.

These are just a few examples and These are just a few examples and not limitations, in any manner.not limitations, in any manner.

We an innovative approach, many We an innovative approach, many applications can be brought to the applications can be brought to the folds of this process to have the best folds of this process to have the best of its advantages.of its advantages.

INC.625 OVERLAY OF FINSTOCK- FOR INDIAN NAVY.

VIDEO1

PUMP SLEEVE COLMONOY -5

CLADDED

PLUG VALVE PLUG-

STELLITE 6 CLADDED

HIGH PRESSURE

VALVE DISC- STELLITE6 CLADDED

ID CLADDING OF A CONTROL VALVE

SLEEVE

AUTOMATED BALL CLADDING

SLURRY VALVE PROFILE DISC

CLADDING- FULL SEQUENCE

AUTOMATEDVIDEO2

IMPORTANT ASPECTS TO IMPORTANT ASPECTS TO SEE……SEE……

ARC - THE TORCH, ANGLE, POSITION AND ARC - THE TORCH, ANGLE, POSITION AND ITS HEALTHITS HEALTH

POWDER FEEDER SETTINGSPOWDER FEEDER SETTINGS GAS SETTINGSGAS SETTINGS OSCILLATOROSCILLATOR WELD SEQUENCEWELD SEQUENCE PRE HEATING AND PRE HEAT MAINTENANCEPRE HEATING AND PRE HEAT MAINTENANCE WATER COOLING SETTINGS – TORCH & JOBSWATER COOLING SETTINGS – TORCH & JOBS

THE TORCH AND THE ARC….THE TORCH AND THE ARC….

ARC CONSTRICTION CONTROL, THE KEY TO GOOD ARC CONSTRICTION CONTROL, THE KEY TO GOOD WELD.WELD.

- TUNGSTEN ELECTRODE CENTRING- TUNGSTEN ELECTRODE CENTRING - ORIFICE 4.6 TO 5.0MM ( RE DRILL AND RE-FACE)- ORIFICE 4.6 TO 5.0MM ( RE DRILL AND RE-FACE) - SET BACK – 2MM (DEPENDS ON ORIFICE)- BIGGER - SET BACK – 2MM (DEPENDS ON ORIFICE)- BIGGER

THE ORIFICE LESSER THE SETBACK.THE ORIFICE LESSER THE SETBACK. -GRINDING THE ELETRODE AND REFIXING, ONCE IN A -GRINDING THE ELETRODE AND REFIXING, ONCE IN A

SHIFTSHIFT - CLEANING THE ORIFICE AND REFI, ONCE IN A SHIFT- CLEANING THE ORIFICE AND REFI, ONCE IN A SHIFT- MONITOR HEALTHY PILOT ARC.MONITOR HEALTHY PILOT ARC.- COOLING OF NOZZLE IN 10 SECS (AFETR SWITCHING COOLING OF NOZZLE IN 10 SECS (AFETR SWITCHING

OFF THE PILOT ARC).OFF THE PILOT ARC).

NO FEATHERY ARC………………..NO FEATHERY ARC………………..

TORCH POSITION – SO TORCH POSITION – SO IMPORTANT!IMPORTANT!

10MM STICK OUT10MM STICK OUT CENTRE OFF SET FOR CYLINDRICAL JOBS.CENTRE OFF SET FOR CYLINDRICAL JOBS. TORCH FOCUSING TOWARDS THE CENTRE TORCH FOCUSING TOWARDS THE CENTRE

(AXIS) FOR CYLIDRICAL JOBS.(AXIS) FOR CYLIDRICAL JOBS. TORCH INCLINATION FOR THE MULTILAYER TORCH INCLINATION FOR THE MULTILAYER

WELDING TO FUSE THE CORNER WELDING TO FUSE THE CORNER (PERPENDICULAR TO THE WELD, PARALLEL TO (PERPENDICULAR TO THE WELD, PARALLEL TO THE SHIFT DIRECTION).THE SHIFT DIRECTION).

SHIFT DISTANCE PROPORTIONAL TO THE BEAD SHIFT DISTANCE PROPORTIONAL TO THE BEAD WIDTH AND THE HEIGHT ( CONTROL OVER THE WIDTH AND THE HEIGHT ( CONTROL OVER THE ROTATION OF THE KNOB EXACTLY), BASE METAL ROTATION OF THE KNOB EXACTLY), BASE METAL TEMPERATURE, OTHER WELDING PARAMETERS.TEMPERATURE, OTHER WELDING PARAMETERS.

THE POWDER THE POWDER FEEDER…..FEEDER…..

GRAVITY ROTARY DRUM.GRAVITY ROTARY DRUM. MAIN PORT SETTING - UNALTERABLEMAIN PORT SETTING - UNALTERABLE SPEED OF THE DRUM ROTATION DECIDES THE SPEED OF THE DRUM ROTATION DECIDES THE

GRAMMAGEGRAMMAGE TWO OUTLET – EQUAL DIVISION FOR GENERAL TWO OUTLET – EQUAL DIVISION FOR GENERAL

TORCHES –HIGH PERFORMANCETORCHES –HIGH PERFORMANCE SINGLE OUTLET FOR ID TORCHESSINGLE OUTLET FOR ID TORCHES OPTIMUM FEED RATE 25 TO 35 GRAMS/MIN.OPTIMUM FEED RATE 25 TO 35 GRAMS/MIN. POWDER GAS - 2 TO 3 LIT PER MIN.(FOR SPHERICAL POWDER GAS - 2 TO 3 LIT PER MIN.(FOR SPHERICAL

ARGON ATOMISED POWDER, MAY VARY FOR OTHER ARGON ATOMISED POWDER, MAY VARY FOR OTHER POWDERS).POWDERS).

SEALING – 100% REQUIRED. PERIODICALLY CHECK SEALING – 100% REQUIRED. PERIODICALLY CHECK THIS AFETR INSTALLTION- O RINGS CONDITION.THIS AFETR INSTALLTION- O RINGS CONDITION.

CHECK FOR POWDER SPRAY ANGLE AT THE TORCH CHECK FOR POWDER SPRAY ANGLE AT THE TORCH ORIFICE, EVRY TIME ON DOUBTS.ORIFICE, EVRY TIME ON DOUBTS.

GAS SETTINGS………GAS SETTINGS……… AS STATED IN WPS – VERY IMPORTANT.AS STATED IN WPS – VERY IMPORTANT. CENTRE- 2 TO 3 LPM, POWDER – 2 TO 3 LPM, SHIELD – 9 LPM TO 11 LPM.CENTRE- 2 TO 3 LPM, POWDER – 2 TO 3 LPM, SHIELD – 9 LPM TO 11 LPM. CENTRE GAS FLOW INCREASES WITH INCREASING DIA OF THE ORIFICE CENTRE GAS FLOW INCREASES WITH INCREASING DIA OF THE ORIFICE

PROPORTINAL TO THE CROSS SECTION AREA.PROPORTINAL TO THE CROSS SECTION AREA. GAS PURITY IS VERY IMPORTANT FOR WELD FINISH AND DEFECT FREE GAS PURITY IS VERY IMPORTANT FOR WELD FINISH AND DEFECT FREE

WELDSWELDS PURE ARGON – COMMERCIAL QUALITYPURE ARGON – COMMERCIAL QUALITY OTHER IMPURITIES OXYGEN, NITROGEN, ETC. ALL IN PPM LEVELS.OTHER IMPURITIES OXYGEN, NITROGEN, ETC. ALL IN PPM LEVELS. REGULATOR PRESSURE SETTING 1.0 TO 1.5 KGS/SQ.CM (15 PSI TO 20 REGULATOR PRESSURE SETTING 1.0 TO 1.5 KGS/SQ.CM (15 PSI TO 20

PSI). MORE THAN THIS GAS WILL BE WATSED.PSI). MORE THAN THIS GAS WILL BE WATSED. CHECK FOR GAS LEAKAGES PERIODICALLY.CHECK FOR GAS LEAKAGES PERIODICALLY. ONE CYLINDER OF 7 CU. M SHOULD WELD AROUND 6KGS.ONE CYLINDER OF 7 CU. M SHOULD WELD AROUND 6KGS.

7 CM = 7000 x1000 CC = 7000 x 1000 CU. ML = 7000 LITERS7 CM = 7000 x1000 CC = 7000 x 1000 CU. ML = 7000 LITERSTHE USAGE = 3 + 3 + 10 = 16 LITRES PER MINTHE USAGE = 3 + 3 + 10 = 16 LITRES PER MINTHIS MEANS 7000/16 = 435 MIN. OF ARCING. THIS AGAIN THIS MEANS 7000/16 = 435 MIN. OF ARCING. THIS AGAIN

MEANS MEANS 30 x 435 = 6.9 KGS. 30 x 435 = 6.9 KGS. WITH OPERATIONAL EFFCIENCY AROUND 6 Kgs. PER CYLINDER.WITH OPERATIONAL EFFCIENCY AROUND 6 Kgs. PER CYLINDER.

Oscillator……….Oscillator………. To be set to get the require width of the land up to To be set to get the require width of the land up to

25 mm. (full bead width up to 25 mm deposit width)25 mm. (full bead width up to 25 mm deposit width) For more than 25 mm multi passes. (each pass 8 to For more than 25 mm multi passes. (each pass 8 to

10mm with 35 to 40% overlap on the side)10mm with 35 to 40% overlap on the side) The pitch of the overlap decides the amount of base The pitch of the overlap decides the amount of base

metal melting and hence the dilution and fusion.metal melting and hence the dilution and fusion. The pitch of the overlap also decides the bead The pitch of the overlap also decides the bead

height effectively and the inter bead level. This has height effectively and the inter bead level. This has to be set for less than 0.3 mm.to be set for less than 0.3 mm.

The oscillator speed has to be set for 1 to 1.5mm The oscillator speed has to be set for 1 to 1.5mm bead ripples ( this is done in relationship with the bead ripples ( this is done in relationship with the positioner speed)positioner speed)

TORCH CLAMPS SHOULD BE STEADFAST TO AVOID TORCH CLAMPS SHOULD BE STEADFAST TO AVOID MULTIPLE ZIG-ZAG WEAVING.MULTIPLE ZIG-ZAG WEAVING.

WELD WELD SEQUENCE….MULTIPASSESSEQUENCE….MULTIPASSES

PRE HEATING AND PREHEAT PRE HEATING AND PREHEAT MAINTENANCE…..MAINTENANCE…..

DONE TO REDUCE THE DONE TO REDUCE THE DELTA T DELTA T FACTOR AND FACTOR AND THERE BY GIVE THE DEPOSIT A COMPRESSIVE THERE BY GIVE THE DEPOSIT A COMPRESSIVE LOAD. THIS WILL AVOID CRACKSLOAD. THIS WILL AVOID CRACKS

UNIFORM HEAT DISTRIBUITION ON THE JOBUNIFORM HEAT DISTRIBUITION ON THE JOB DONE FOR ALL ALLOYS EXCEPT SSDONE FOR ALL ALLOYS EXCEPT SS FOR CARBON STEELS OVER 25MM THICKNESSFOR CARBON STEELS OVER 25MM THICKNESS WELDING OVER HF MATERIAL (STELLITE OR WELDING OVER HF MATERIAL (STELLITE OR

COLMONOY CALLS FOR HIGHER PREHEAT)COLMONOY CALLS FOR HIGHER PREHEAT) CHECK THE WPS FOR PREHEAT TEMPERATURES CHECK THE WPS FOR PREHEAT TEMPERATURES

AND SEEK GUIDANCE.AND SEEK GUIDANCE. STELLITE CRCKS ARE 90% DUE TO LACK OF STELLITE CRCKS ARE 90% DUE TO LACK OF

PREHEATING AND PRE HEAT MAINTENANCEPREHEATING AND PRE HEAT MAINTENANCE THE JOB HAS TO BE COOLED IN WORMICULITE THE JOB HAS TO BE COOLED IN WORMICULITE

SAND TO AVOID NON-UNIFORM CONTRACTIONSAND TO AVOID NON-UNIFORM CONTRACTION

WATER CHILLER WATER CHILLER SETTINGS……SETTINGS……

THIS HAS TO BE SET TO AVOID WATER THIS HAS TO BE SET TO AVOID WATER SWEATING IN THE TORCH AND AT THE SWEATING IN THE TORCH AND AT THE SAME TIME EFFECTIVE COOLING.SAME TIME EFFECTIVE COOLING.

OPTIMUM SETTING IS 22 DEG. C OR 23 OPTIMUM SETTING IS 22 DEG. C OR 23 DEG.C.DEG.C.

FLOW RATE DESIRABLE IS MIN. 6LPM FLOW RATE DESIRABLE IS MIN. 6LPM AT THE RETURN WATER END.AT THE RETURN WATER END.

FLOW SWITCH IS MANDATORY TO FLOW SWITCH IS MANDATORY TO AVOID TORCH BURNING OR DAMAGEAVOID TORCH BURNING OR DAMAGE

The facts prove……..The facts prove……..

That PTAW weld overlaying process is a very That PTAW weld overlaying process is a very effective method to get thick claddings.effective method to get thick claddings.

This high energy arc welding process used in This high energy arc welding process used in automation delivers excellent and accurate automation delivers excellent and accurate fusion bonded weld overlays coupled with lowest fusion bonded weld overlays coupled with lowest possible dilution and very good weld appeal, possible dilution and very good weld appeal, compared to other welding processes, IF WE SET compared to other welding processes, IF WE SET THE MACHINE VARIABLES PROPERLY.THE MACHINE VARIABLES PROPERLY.

It can be very disastrous if NOT handled properly.It can be very disastrous if NOT handled properly. Proper observation teaches you all.. To be very Proper observation teaches you all.. To be very

effective.effective.BE READY FOR THE EXPERIMENTATION AND BE READY FOR THE EXPERIMENTATION AND

CONTINUOS LEARNING.CONTINUOS LEARNING.UNNAL MUDIYUMUNNAL MUDIYUM THAMBI……………………………THAMBI……………………………