12

SUPPORT MATERIAL FOR INDEPENDENT LEARNING ENGAGEMENT (SMILE)

A Joint Project of

SCHOOLS DIVISION OF DIPOLOG CITY and the

DIPOLOG CITY GOVERNMENT

TVL (SMAW NCII)

Quarter 1 – Module 2: Week 2

Essential Variable of Welding Medyrose G. Costello

TVL (SMAW NC II) – Grade 12 Support Material for Independent Learning Engagement (SMILE) Quarter 1 – Module 2: Essential Variable of Welding First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them.

Inilimbag sa Pilipinas ng

Department of Education – Rehiyon IX - Dipolog City Schools Division

Office Address : Purok Farmers, Olingan, Dipolog City

Zamboanga del Norte,7100

Telefax : (065) 212-6986

E-mail Address : dipolog.city@deped.gov.ph

Development Team of the Module

Writer: Medyrose G. Costello

Editor: Cris Olasiman

Reviewer: Lilibeth G. Ratificar, EMD

Illustrator:

Layout Artist: Jessa Rose D. Ajero

Management Team:

Virgilio P. Batan, Jr. – Schools Division Superintendent

Jay S. Montealto – Asst. Schools Division Superintendent

Amelinda D. Montero – Chief Education Supervisor, CID

Nur N. Hussien – Chief, Education Supervisor SGOD

Ronillo S. Yarag – Education Program Supervisor, LRMS

Leo Martinno O. Alejo – Project Development Officer II, LRMS

Lilia E. Abello Ed D

1

What I Need to Know

At the end of this module, you should be able to:

1. Weld carbon steel plates in flat position1G (TLE_IAAW9-12GW-Ia-j1)

1.1 Perform root pass with root penetration not exceeding the

allowable tolerance.

1.2 Check root penetration in accordance with acceptable standards

1.3 Perform stringer/layered beads in accordance with welding

standards

1.4 Observe welding codes and standards on: undercut, excessive

penetration, lack of fusion, burn-through and cracks.

1.5 Observe weld capping capping/final pass not exceeding

allowable tolerances specified by welding codes/ standards.

1.6 Conducts weld inspection of the finish weldment in accordance

with welding standards.

1.7 Use appropriate Personal Protective Equipment (PPE)

1.8 Perform Proper Housekeeping

The week 2 module 2 contains lesson which is:

• Lesson 2 –Week 2– Essential Variables of Welding (SMAW)

After going through this module, you are expected to:

1. Identify the Five Essential Variables of Welding.

2. List and describe the five essential variables of welding.

3. Know the possible welding discontinuities.

2

What I Know

DIAGNOSTIC/PRE TEST MULTIPLE CHOICE: Direction: Write the letter of the correct answer.

_____1. Arc length should be as long as ______. A. 5/16 B. The diameter of the uncoated portion of electrode

C. 1/3 to 1/2 the total thickness of the work-piece. D. The diameter of the electrode

_____2. The _____angle is in the line of the welding and may vary from 5° to 30°.

a. Work C. current b. Travel D. arc

_____3. When the welding current is too low, _____.

A. beads pile up in the base metal B. there is not enough heat to melt the base metal

C. the beads will be irregular in shape D. all of the above

______4. Undercutting on vertical plate can be avoided by ____. A. increasing the amperage

B. changing the electrode angle C. increasing the arc length D. all of the above

______5. Welding current that is too high results in excessive____. A. bead height

B. travel speed C. Spatter

D. Overlap MATCHING TYPE

Direction: Match columns A to Column B

A B

____ 1. the bead weld will show narrow pointed

ripples if the _______ is incorrect. A. electrode

____ 2. The properties of the base metal

determine the ____ to be use. B. arc length

____ 3. The _____ may vary from 5-30° from

vertical in the line of the welding. C. current

____ 4. If the _______ is too high , the electrode will melt too fast.

D. Travel Speed

____ 5. The ______ should be approximately 1/8” when using 1/8” diameter

electrode.

E. Travel Angle

3

TRUE OR FALSE

Direction: Write TRUE if the statement is True and write FALSE if the

statement is False.

______ 1. The length of an arc is determined by the size of the electrode.

_____ 2. A narrow weld bead with pointed ripples results if the travel is too

slow.

_______3. Welding with too long arc gap results an overlapping.

_______ 4. Undercutting can occur if the current is set too high.

_______ 5. The work angle of an electrode is approximately 90° .

4

Learners please read the information given and

answer the questions religiously.

What’s In

Essentials of welding. When we talk about essentials, it means

necessary or important things that we have to know or to do. In welding, it is

not just tacking and weld the piece of metals is enough. There are things that

we have also to consider like good weld profile and welding technique. In order

to have a good weld profile, we have to consider a the 5 essentials variables of

welding which are: Current setting, Length of arc, Angle of electrode, Speed Of

travel and Selection of Electrode. For an easy way in remembering these five

essential variables is by remembering the first letter in each one and spell the

word CLASS.

Essentials of welding

o C –Current Setting

o L– Length of Arc

o A– Angle of Electrode

o S– Speed of Travel

o S– Selection of Electrode

If these five essentials are not followed nor done even just one of it, there

will be some weld discontinuities or defects will occur such as; porosities,

overlap, undercut, incomplete fusion, incomplete penetration, insufficient

throat, cracks porosity, insufficient leg size, excessive convexity, excessive

spatters, slag inclusions and poor fusion.

Essential Variables of

Welding

Lesson

1

5

What’s New

ACTIVITY 1: MATCHING TYPE

Direction: In this activity, pictures have been shown below. Match the

pictures to its corresponding 5 essentials of welding. Draw a line to connect

each other.

. A B

1. Current Setting

A

2. Length of Arc B

3. Angle of Electrode C

4. Speed of Travel D

5. Selection of Electrode E

6

What is It?

FIVE ESSENTIAL VARIABLES OF WELDING

Welding is the practical skill that requires continual practice and careful attention to the variables that the welder controls to improve. The old

golden rule “practice makes perfect” applies to welding in that the more you

do, as long as you or someone evaluates your welds, the better you become.

Essentials of welding are very important in producing a quality weld

and the term variable as used in this text means that the welder has to control of either before welding or during welding. There are five (5) essentials

of welding. it includes the use of the correct electrodes size, current, arc length

or voltage, travel peed and electrode angles.

KEY POINT: For an easy way in remembering these five essential variables is by

remembering the first letter in each one and spell the word CLASS.

1. Current Setting

2. Length of Arc

3. Angle of Electrode 4. Speed of Travel 5. Selection of Electrode

CURRENT SETTING

The welding current or amperage is essential to producing welds with good appearance and the required strength characteristics. The welder

controls the amperage variable by setting the amperage on the welding machine prior to welding.

The amperage setting varies according to the size of the electrode, the

type of electrode, and the type of current AC, DCEN or DCEP you are using.

TYPE OF CURRENT:

• AC – Alternating Current

• DCEN – Direct Current Electrode Negative (Straight Polarity)

• DCEP – Direct Current Electrode Positive (Reverse Polarity)

Some electrodes are designed to work best on a given Current and

Polarity, for example E-6010 should be used with DCEP (direct current electrode positive). Some electrodes are designed to work best on DCEN while others allow a selection of Current to be used.

7

The chart below shows typical amperage ranges

Amperage may be referred to as the heat by

some welders. An excellent place to find amperage

ranges, recommended current and polarity and information on electrode applications are the Electrode Selection Guidebooks available at any welding

supply store. The amperage range is fine-tuned by the welder to the correct amperage before welding on an actual work piece or test piece by running practice

welds on a piece of scrap metal in the position of welding as follows;

1. Run a practice weld at the lower recommended range setting.

2. Run a second practice weld at the higher recommended setting. 3. Compare the two welds for evidence of a well formed bead, good fusion,

lack of defects, and a smooth transition into the base metal. 4. If necessary reduce the amperage from lower to highest amperage until

a satisfactory weld bead is produced.

5. It is important to try different setting to avoid wasting time with a setting that is to low or too high and will need to be changed later.

The chart below gives an idea of the evaluation process;

In example A the E-6010 weld made with the correct amperage appears

properly formed with the appropriate width and consistency. In example B the weld made with amperage setting too low appears thin and stringy.

In example C the weld made with amperage setting too high appears wide and flat with excessive spatter and evidence of undercut.

A B C

A) Amperage correct B. Amperage too low C. Amperage too high

The correct amperage is one that provides a good weld and is not based on a specific number

on the machine.

KEY POINT: Remember conditions may change for example; if you are welding

multiple passes in the vertical position and using a weave technique you may need

to increase the amperage when weaving over a prior weld bead.You may want to use higher setting for welding flat and horizontal than for welding in other positions.

One welder (operator) may prefer to use a slightly higher setting and travel faster than you, so set the amperage for your technique

8

LENGTH OF ARC / ARC LENGTH

ARC is the distance from the tip of the electrode to the base metal and can be varied from lightly touching the heal at an angle sufficient to maintain an arc to a distance for enough from the base metal to extinguish the arc.

The arc length is too long, the metal melts off the electrode in large globules that wobble as the wavers. These large globules produce a wide,

spattered, and irregular bead with insufficient fusion between the base metal and the deposited metal. An arc length that is too short fails to generate

enough heat to melt the base metal properly, producing high, uneven beads with irregular ripples. Depositing welds using too short an arc length also

increases the possibility of electrode sticking to the work piece.

The arc length required depends on the size of the electrode used

and the welding task. Small- diameter electrode- requires a shorter arc length than large-diameter electrodes. For better control of the weld pool, the

arc length should typically be approximate the diameter of the electrode. For example, an

electrode 1/8” in diameter should have an arc length of about 1/8”. A shorter arc length is typical

used for horizontal, vertical, and overhead welding position because it gives better control of the weld

pool.

The proper arc length also prevents impurities from entering a weld. A correct weld

bead has the proper height and width and uniformly spaced ripples. A long arc length allows

the atmosphere to flow into the weld area, permitting impurities of nitrides and oxides to form. Additionally, when the arc length is too long,

heat from the arc stream is dissipated too rapidly, causing considerable metal spatter.

Figure 11-2. If the arc length is too short, the bead

will have a narrow width and excessive height. Correct arc length is necessary for proper bead formation

*The arc length should be approximately equal the diameter of the electrode.

9

ELECTRODE ANGLE

The electrode angle affects the weld bead shape, particularly in fillet and deep groove welds. The electrode angle is determined by the travel angle

and the work angle. Travel angle is an angle less than 90° between the electrode axis and the line perpendicular to the weld axis and in a plane

determined by the electrode axis and the weld axis. The travel angle is along the weld axis and varies from 5° to 30° from the vertical, depending on welder preference and conditions. Work angle is an angle less than 90° in a line

perpendicular to the work piece and in a plane determined by the electrode axis and the weld axis. For example, the work angle normally is 90° when

making a groove weld in flat position.

Ordinarily, a slight angle of the electrode in either direction from the work angle does not affect weld appearance or quality.

However, when undercuts occur in the vertical plate of a fillet weld, the angle of the arc should be lowered and the arc directed more toward the

vertical plate. Work angle is especially important in multiple-pass fillet weld.

Figure 11-4. The correct electrode angle is required to make a proper weld.

*The depth of penetration should be one-third to one-half the total thickness of the

weld bead

10

TRAVEL SPEED If the travel speed is too fast, the weld pool does not last long enough and impurities are locked in the weld. The resulting bead is narrow, with pointed ripples.

If the travel speed is too slow,. The metals and the beads is high and wide, with straight ripples. The correct travel speed produces a smooth weld bead with evenly spaced ripples.

Figure 11-3. Proper bead formation is dependent on many variables, which must be controlled to prevent a poor- quality bead

SELECTION OF ELECTRODE

Electrode selection must take into account the position of the weld, the properties of the base metal, the diameter of the electrode, the type of joint,

and the current. Different electrodes are manufactured to meet various welding requirements.

There are a variety of electrodes available for welding a wide range

of metals. The electrode for a given application must be selected carefully to provide the strength characteristics required for the weld joint. One of the

most useful tools for electrode selection is the Electrode Handbooks available from welding supply outlets. These handbooks provide information from

electrode classification to application and usability.

Some factors to be consider in the selection of electrodes: • Types of metal - requires different types of electrode. Because of

a mismatch of electrode used will cause defects and not proper

fusion of metal due to its incompatibility. Example: carbon steel electrode is not compatible with stainless steel or aluminum steel.

• Thickness of metal – it requires different size of electrode base on the thickness of metal. For example 5/32 size of electrode is

not compatible with 2mm thickness of metal. • Task to do – require different types of metal because not all the

task to do uses the same type of electrode. For example, 6010 or

11

6011 cannot be used for capping/ final pass because it has a rough surfaces.

In general the electrode weld metal must be matched to the type and composition of the base metal being welded. Further some electrodes within the available scope are designed for specific purposes. Some of the most

widely used Electrodes are those used for welding carbon Steel.

The following is a brief description of the most commonly used electrodes for welding Carbon Steel. The electrodes are classified by a letter

and numbering system as follows:

(weldingandndt.com)

MEANING OF CODE ON ELECTRODE E –it means the ELECTRODE. The electrodes are classified by a letter and

numbering system as follows:

1ST TWO DIGIT - means the tensile strength and it is measured by psi (pounds per square inch. TENSILE STRENGTH is defined as the ability

of the weld metal to withstand forces acting to pull it apart……. EXAMPLE: 60 means 60, 000 psi

3rd SINGLE DIGIT – it mean the position.

THE LAST DIGIT – it indicates the type of flux or electrode covering and in

turn determines the type of current, penetration and appearance of the weld.

Indicates Electrode Tensile strength in

thousand pounds

per square inch

Welding Position Flux type

1- All Position Type of Current

2- Horizontal & Flat Electrode Characteristics

3- Vertical Downward

12

CHART SHOWING DISCONTINUITIES IN SMAW AND THEIR CAUSES

DISCONTINUITIES

POSSIBLE CAUSES

Excessive Convexity • Slow travel speed that allows weld metal to build up.

• Weld currents too law.

Insufficient Throat • Travel speed to fast and current too high.

• Improper placement of weld beads when multiple pass welding

Undercut • Amperage too high • Arc length too long increasing the force of the arc so that it cuts

into corners. • Improper welding technique causing the corners to be left unfilled

or cut into. • Groove joint not completely filled and overlapped

Insufficient Leg Size • Wrong electrode angle causing the weld to be deposited heavily on one side

• Wrong electrode angle on multiple pass weld causing the weld to overlap incorrectly.

Poor Penetration • Amperage too low

• Too fast travel speed • Improper electrode angle at the root of the joint.

• Using too large electrode for the root of joint.

• Improper weave technique. • Using the wrong electrode for the desired joint penetration.

(example: Using e6013 instead of E6010)

Poor Fusion • Amperage too low • Too fast travel speed

• Improper electrode angle for the root of joint • Improper weaving technique that does not allow enough time at

the sides of the joint.

• Using wrong electrode for the application.

Overlap • Amperage too low • Travel speed too slow

• Electrode too large with low currents.

Porosity • Dirty base metal, painted or galvanized surfaces. • Arc length too long especially with E7018 electrodes.

• Moisture in low hydrogen electrodes • Strong wind or fans, enough to break down the shielding gas.

Slag Inclusion • Improper manipulation of the electrode especially with E6013.

• Improper cleaning and slag removal between multiple pass.

Cracks • Using wrong electrode for the application.

• Using excessively high amperage on some metals.

Excessive Spatter • Amperage too high/too high current • Electrode angle too extreme or too incline.

13

What’s More

Activity 2: CHECKLIST MAKING

DIRECTION: Make a list on the following. For this activity use another

sheet of paper then write your name, week number and the activity

number/code.

I ESSENTIAL VARIABLES OF WELDING

✓ ______________________ ✓ ______________________

✓ ______________________ ✓ ______________________ ✓ ______________________

II TYPES OF CURRECT

✓ ______________________

✓ ______________________ ✓ ______________________

III ARC LENGTH DEPENDS ON….

✓ ______________________ ✓ ______________________

IV ANGLES OF ELECTRODE

✓ ______________________ ✓ ______________________

What I Have Learned

Activity 3: Essay

DIRECTION: Answer the following questions using your idea base on the

information given. In each question your answer must be at least 50 words or

more. For this activity use another sheet of paper then write your name, week

number and the activity number/code.

14

1. What are the five essentials of welding, and why they are important? 2. Why too fast travel speed can cause poor penetration and under cut?

3. Why do we have to consider the type of metal in the selection of electrode?

Rubrics:

CRITERIA 5 points 3 points 1 point

ACCURACY

The answer

given is 100%

accurate.

The answer

given is partly

correct.

The answer

given is

incorrect.

GRAMMATICALLY

CORRECTS

Statements

are 100%

grammatically

correct.

1-2 sentences

are

grammatically

incorrect.

3 or more

sentences are

grammatically

incorrect

Total score

What I Can Do

Activity 4 : ENUMERATION

Direction: To test your knowledge, enumerate the following answers on the

questions given. For this activity use another sheet of paper then write your name,

week number and the activity number/code.

For this activity use another sheet of paper then write your name, week

number and the activity number/code.

1-5 What are the five essentials of welding?

6-8 What are the tree factors to be consider in the selection of electrode?

9-10 What are the possible cause of the following. Give at least two of each kind.

9-10 – Poor penetration

11-12- Undercut

13-14- Porosity

15-16- Overlap

17-18- Excessive spatter

19-20- Poor fusion

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Assessment

MULTIPLE CHOICE:

Direction: Write the letter of the correct answer. _____1. Arc length should be as long as ______.

A. The diameter of the uncoated portion of electrode B. 5/16

C. 1/3 to 1/2 the total thickness of the work-piece. D. The diameter of the electrode

_____2. The _____angle is in the line of the welding and may vary from 5° to 30°.

A. Work B. Arc

C. Current D. Travel

_____3. When the welding current is too low, _____. A. beads pile up in the base metal

B. there is not enough heat to melt the base metal C. the beads will be irregular in shape

D. all of the above

______4. Undercutting on vertical plate can be avoided by ____.

A. increasing the amperage B. changing the electrode angle

C. increasing the arc length D. all of the above

___ ____5. Welding current that is too high results in excessive____.

A. spatters

B. travel speed C. bead height

D. Overlap

16

MATCHING TYPE

Directions:

Match columns A to Column B

A. B.

TRUE OR FALSE

Direction: Write TRUE if the statement is True and write FALSE if the

statement is False

______ 1. Undercutting can occur if the current is set too high.

_____ 2. The length of an arc is determined by the size of the electrode _______3. Welding with too long arc gap results an overlapping.

_______ 4. A narrow weld bead with pointed ripples results if the travel is too

slow.

_______ 5. The work angle of an electrode is approximately 90°.

____ 1. the bead weld will show narrow pointed ripples if the _______ is incorrect.

A. electrode

____ 2. The properties of the base metal determine the ____ to be use.

B. arc length

____ 3. The _____ may vary from 5-30° from

vertical in the line of the welding. D. current

____ 4. If the _______ is too high , the electrode

will melt too fast. D. Travel Speed

____ 5. The ______ should be approximately

1/8” when using 1/8” diameter electrode.

E. Travel Angle

16

Additional Activities

ACTIVITY 5: GUIDE MAKING

Direction: Make a guide on your own that you will use when you perform before,

during and after welding base on the formation that you have read from this

module. For this activity use another sheet of paper then write your name, week

number and the activity number/code.

Deadline: Friday this week.

Example:

Task Things to do:

1. Current setting • Check cable connections

• Test run on the test plate

PERFORMANCE RUBRICS:

RUBRICS SCORE CRITERIA

5 pts 3 pts 1pts

ACCURACY All the task on the guides are correct

Some of the task are incorrect

Most of the task are in correct.

RELEVANT

The guide is relevant

to the task

The guide is somewhat

relevant to the task

The guide is not

relevant to the task

TIMELINESS The activity submitted on or

before the deadline

The activity given submitted the day after

the deadline

The activity given submitted 2 0r more

days after the deadline

TOTAL SCORE

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Answer Key

What I Know

I Mulptiple Choice

1.B 2.B

3.B 4.D

5.C

II Matching Type

1.D

2.A

3.E

4.C

5.B

III True or False

1.T 2.F

3.F 4.T

5.T

What's More

I

1.Current Setting

2.Length of Arc 3.Angle of Electrode

4.Speed of Travel

5.Selection of elev trode

6.AC 7.DCEP

8.DCEN 9.Size of Electrode

10.Welding Task

11.Travel angle 12.Working angle

WHAT CAN I DO ( in any

order)

1-5 essentials of welding

•Current setting

•Length of arc

•Angle of electrode

•Speed of travel

•Selection of

electrode 6-8 -Factors to be consider

in the selection of

electrode.

•Type of metal

•Thickness of

metal

•Task to do 9-10 – Poor penetration

•Low current

•Too fast travel

speed

WHAT CAN I DO 11-12- Undercut

•High current

•Long arc gap 13-14- Porosity

•Dirty work piece

•Arc too long

•Moist/damp electrode

•Strong wind

velocity

15-16- Overlap

•Slow travel speed

•To large electrode 17-18- Excessive spatter

•High current setting

•Arc too long

•Angle too incline

19-20- excessive convexity

•Slow travel speed

•Low current

Assessment

I Mulptiple Choice

6.A

7.D 8.B

9.D 10.A

II Matching Type

6.D

7.A

8.E

9.C

10.B

III True or False

6.T

7.T

8.F 9.F

10.T

18

References:

Manuals/Handbooks

• Department of Education Central Office. Curriculum Guide (CG)

• Department of Education Central Office. Most Essential Learning Competencies (MELCS)

• Department of Education Central Office and Region X. Quarter 1-module 1 by Mary Kris S. Agbo

• Department of Education. K-12 Basic Education Curriculum. Technology and Livelihood Education. Industrial Arts- Shielded

Metal Arc Welding (SMAW). Grade 10 - Specialization

• Written And Published by: NORMAN J. ASHLEY DELTA SCHOOL OF TRADE 5418 Pulaski Highway

Baltimore, Maryland Page. 34-41

Websites:

• www.DELTASCOOLOFTRADES.com

• (www.arcraft plasma.com)

• weldingandndt.com)

• En.wikipedia.com

• www.accenics,com

• www.nmri.go

• www.waybuilder.net

• www.millerweld.com

• www.reseaarchgate.net

• www.migweld.co.uk

• www/marineweld.com