cswip day3

8/10/2019 CSWIP day3

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Volts

Amps

OCV

Constant Voltage Volt/Amp Characteristic*

Small change in voltage

=

large change in amperage*Changes in

arc length*

The self

adjusting arc.



Power return

cable*

Transformer/

Rectifier

Power cable &hose assembly

Liner for wire

Welding gun

assembly

!ternal wire

feed unit

Power control

"anel

#nternal wire

feed system

$%g wire s"ool



Plain to" roller

'alf groo(ed

bottom roller Wire guide*

#nternal wire dri(e system*



Torch body

Contact ti"s

)"ot welding

s"acer

as diffuser

+o,,les or

shrouds

Torch head assembly

-Less no,,le*

n/ff switch

'ose "ort



Types of metal transfer:

Dip transfer0 1 23 Welding (olts. Low am"s. & C42 as.

5ll "ositional. Low heat

in"ut. Low de"osition rate

Spray transfer: 6 23 Welding (olts 'igh am"s 5r/C42 7i!

8own9hand only. -steels 'igh heat in"ut. 'igh de"osition rate

Pulse transfer: :ariable "ulses of high current

5ll "ositional. Controlled heat in"ut. 'igh de"osition rate*lobular transfer occurs between di" & s"ray; but is unstable*



$ 5 Transformer/Rectifier -Constant (oltage ty"e

2 5 "ower and "ower return cable

< 5n #nert; acti(e; or mi!ed shielding gas -5rgon or C=

3 as hose; flow9meter; & gas regulator

% 7# torch with hose; liner; diffuser; contact ti" & no,,le

> Wire feed unit with correct dri(e rolls -Push or Pull

? lectrode wire to correct s"ecification and diameter

@ Correct (isor & glass; all safety clothing and good e!traction*



% Ti" si,e/condition

$ WA)/5m"erage

< Wire ty"e & Ø

? Liner si,e

B #nsulation/e!traction

2 C: & 5rc :oltage

3 as ty"e & flow rate

> Roller si,e & "ressure

@ #nductance settings

$4 Connections

$$ 8uty cycle $2 5ngles & tra(el s"eed*



< Porosity -Arom loss of gas shield on site etc*

$ )ilica inclusions -Poor inter9run cleaning

2 Lac of side wall fusion -Primarily with di" transfer

7ost welding im"erfections in 7#/75 are caused by lac

of welder sill; or incorrect settings of the eui"ment

The use of low uality wires will cause wire feed "roblemsWorn contact ti"s will cause "oor "ower "ic u"; or transfer

Dad "ower connections will cause a loss of (oltage in the arc*



Avantages:

!" #o$er s%ill re&uire

'" (asily automate

)" All positional Dip/Pulse"

+" Thic%/thin materials

Disavantages:

!" #ac% of sie$all fusion

'" ,ange of consuma-les

." igh prouctivity O/0"

)" #oss of gas shiel/site

+" Comple1 e&uipment

." igh o2one levels*



Transformer/

Rectifier

Power return

cable

Reel of wire

Power control "anel

Welding carriage

control unit

ranulated

flu!*

Carriage assemblywith flu! ho""er



Possible weld metal E com"osition*

Change in weld metal com"osition*

Ty"ical )5W

"re"aration*

ffect of increase arc (oltage

)5W with lo$ arc (oltage

!3 4ire '3 0lu1 )3 Dilution

!3 4ire '3 0lu1 )3 Dilution

!

')

!

')

)hort arc length

Long arc length



$ 5 Transformer/Rectifier -Constant (oltage ty"e

2 5 "ower and "ower return cable

< 5 torch head assembly

3 5 granulated flu!

% 5 flu! deli(ery system

> 5 flu! reco(ery system

? lectrode wire to correct s"ecification and diameter

@ Correct safety clothing and good e!traction*



% Wire F & condition

$ WA)/5m"erage

< Alu! ty"e & mesh si,e

? Alu! deli(ery/reco(ery

B #nsulation/duty cycle

2 C: & 5rc :oltage

3 Alu! condition

> Wire )"ecification

@ lectrode stic9out

$4 Connections

$$ Ti" si,e & condition $2 )"eed of tra(el*



2 )olidification cracs -Arom ) "ic u" from high dilution$ Lac of fusion -Caused by high le(els of arc blow

< )hrinage ca(ities -Arom high de"th0width ratio

7ost welding im"erfections in )5W are caused by incorrect

setting of the eui"ment; using incorrect or wrongly dried

consumables; or welding "lates that ha(e not been "ro"erly

cleaned. 7inor changes in the welding "arameters of )5W canha(e a major effect on weld com"osition and weld uality.

5a ca-le connections can ha(e a serious effect on changes in

arc length; and thus effect alloying to the weld (ia the flu!*

3 Porosity -Gsing dam" flu!es; or un9cleaned "lates*



Avantages:

!" #o$ $el metal costs

'" (asily mechani2e

)" #o$ O2one prouction

+" igh prouctivity O/0"

Disavantages:

!" ,estricte in position

'" Arc -lo$ $ith DC

." 6o visi-le arc light 7/V"

)" Shrin%age cavities :$"

+" Penetration control

." Varia-le compositions*



:ideos

)5D

H7#/75 Welding )teelsI

r eui(alent -<4 minutes*



:ideos

7illar

H)ubmerged 5rc WeldingI

r eui(alent -24 minutes*



All those things use up in the prouction of a $el

Though generally; we refer to those elements that are used in

a s"ecific welding "rocess i.e0

(lectroes8 4ires8 0lu1es an 9ases*



#n 775/)75W the only consumables used are short

electrodes; which are co(ered in a flu! coating

This flu! coating has many functions and there are

many different ty"es

These functions are not limite too8 -ut inclue:

!" To ai arc stri%ing

'" To sta-ili2e the arc)" 0orm a shieling gas

+" To a eo1iants

." To a alloying elements

;" To form a protective slag<" To refine soliifying metal

" To control hyrogen content *



Classification: 7ainConstituent

:

)hielding gas:

eneralGses:

Rutile0 >4$< Titania

Ti2

C2 eneral

Pur"ose

Dasic0 ?4$@ Calciumcom"ounds

C2 'igh ualitywor

Cellulosic0>4$4

Celluloseround cocoanut shells

'ydrogen

Pi"e rootruns*

The core $ire for most >>A electroes is of a lo$ &uality steel8 as this is a cheap

metho of manufacture an the steel $ill -e refine uring the process of $eling

-y the refining agents an elements containe in the flu1 coating*



lectrode

Tensile & yield strength

Toughness 2@ & 3? Joules

Alu! coating ty"e

lectrode efficiency

Positional ca"abilities

lectrical "arameters

Low hydrogen "otential

-5fter baing

%$<<D

Strength Toughness Coating )hown on all electrodes*




Alu! coating ty"e

Toughness 3? Joules

lectrode

Tensile & yield strength

5ny light alloying com"ositionlectrical "arameters & efficiency

Low hydrogen content achie(able*

3> < $+i D

Strength Toughness Coating )hown on all electrodes*



lectrode

Tensile strength

-P)# !$444


Alu! coating &

electrical characteristics*

@4 $@



$0 lectrode si,e

20 lectrode condition

<0 lectrode s"ecification

8iameter & length*

Cracs; chi"s & concentricity*

Correct s"ecification/code*

( .! )) 5



ases used for T?90

Argon or elium or a mi!ture of these gases*

'elium gas has higher ioni,ation "otential than argon and gi(esdee"er "enetration; whilst argon is denser than air and gi(es good

co(erage of the weld area in the down hand "osition. We would

need 29< times the flow rate of helium to get the same co(erage

as helium is less dense than air. #n the o(erhead "osition the

re(erse is true. We often mi! these gases to get both benefits*

We sometimes use additions of nitrogen when welding some

stainless steels; or co""er *



ases used for >?90 Argon or elium

CO' : :ery good "enetration; cannot su""ort s"ray transfer

"roduces an unstable arc; with lots of s"atter

Argon: )hallow "enetration. :ery stable arc; with low s"atter

We mi! both gases in mi!ture of between . @ 'E CO' in

argon to get the benefits of both gases*

Aor stainless steels we use argon with a 'B o1ygen; this

gi(es more fluidity to the weld and an im"ro(ed toe blend*

ases used for >A90 CO' or mi!tures of CO' and Argon*



Wires must be drawn as de"osited and are therefore of (ery high

uality. lectrode wires for 7# are the same as rods for T#*

9raes: Composition )ingle; double; and tri"le de9o!idised wires*

uality of $ining:

Random wound. Layer wound. & Precision layer wound

4ires iameters:

4.> 9 62.3 mm Ø su""lied on $ g -fine wire & $% g s"ools*

The uality of tem"er and co""er coating is also (ery im"ortant.

The co""er coating on 7# wires ma!imises the current "ic u"*

)"ecifications for wires are as "er their chemical compositions*



Consuma-les for Su-merge Arc 4eling consist of a $ire

an a flu1*

The $ire is similar to that of soli $ire >?9/>A9 an is

chosen from a ta-le of chemical compositions*

0lu1es are varie an are classifie -y their metho ofmanufacture an composition*



The ' methos of flu1 manufacture are:

!" 0use

'" Agglomerate*

Aused flu!es are baed at a high tem"erature after mi!ing

and all com"onents are fused together lie glass. The slab

is then smashed into (ery small "articles and sifted into

grain si,es*

5gglomerated flu!es are not baed as high as the fused

flu!es and are held together as "articles by binding agents.

These flu!es are also sifted into grain si,es*



0use flu1es: cannot contain certain alloying elements

such as Aerro 7anganese; and tend to be used for lower

uality wor. These flu!es are non moisture absorbant*

Agglomerate flu1es: contain many alloying elements;

but are "rone to moisture absor"tion. They are used for

higher uality wor *

All Su-merge Arc 0lu1es shoul -e separately an

carefully store in a ry area*



Aused )5W Alu!es

*



5gglomerated Alu!es

*



0use0

Daed at high tem"erature; glossy;hard and blac in colour;

cannot add ferro9manganese; non moisture absorbent and

tends to be of the acidic ty"e*

Agglomerate:

Daed at a lower tem"erature; dull; irregularly sha"ed;

friable; -easily crushed can easily add alloying elements;

moisture absorbent and tend to be of the basic ty"e*



Pi"e :isual #ns"ection AormPage 1 of 3 CSWIP VISUAL INSPECTION PIPE REPORT

6ame E5loc% capitalsFGGGGGGGGGGGG SignatureGGGGGGGGGPipe ?entHGGGGGGGG

Coe/Specification useGGGGGGGGG4eling ProcessGGGGGGG Ioint typeGGGGGG

4eling positionGGGGGGGGGG Outsie J Thic%nessGGGGG Date GGGGGGGG

5 D C

C 8 5

Complete as per plate report form *



Practice obser(ing & re"orting using the "i"es and forms

"ro(ided.

Gse your nominated "i"e code for all your (isual ins"ections

as this will hel" you become con(ersant with the s"ecification.

Practice this u" and till the end of the day; or as directed by

your course lecturer *

cswip day3

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