04 smaw electrode polarity, 05 effects of stick welding various materials, Smaw electrode polarity -4 – Tweco 175 TE Arcmaster User Manual

Page 32: Effects of stick welding various materials -4, Arc master 175 te operation

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arc master 175 te

oPeration

Operation 4-4 Manual 0-5116

Metal Being Joined

Electrode

Comments

Mild Steel

E6013

Ideal electrodes for all general purpose work,

features include outstanding operator ap-

peal, easy arc starting, and low spatter.

Mild Steel

E7014

All positional electrode for use on mild and

galvanized steel furniture, plates, fences,

gates, pipes and tanks, etc. Especially suit-

able for vertical-down welding.

Cast Iron

99% Nickel

Suitable for joining all cast irons except white

cast iron.

Stainless Steel

E318L-16

High corrosion resistance. Ideal for dairy

work etc.

Copper, Bronze, Brass, Etc.

Bronze 5.7

ERCUSI-A

Easy to use electrode for marine fittings,

water taps and valves, water through floats

arms, etc. Also for joining copper to steel

and for bronze overlays on steel shafts.

High Alloy Steel, Dissimilar

Metals, Crack Resistance, All

Hard-To Weld jobs

E312-16

It will weld most problematic job such as springs,

shafts, broken joins, mild steel to stainless and

alloy steels. Not suitable for aluminium.

4.04 SMAW Electrode Polarity

Stick electrodes are generally connected to the "+"

Positive Output Terminal and the work lead to the

"−" Negative Output Terminal but if in doubt consult

the electrode manufacturer's literature for further

information.

4.05 Effects of Stick Welding Various

Materials

High Tensile and Alloy Steels

The two most prominent effects of welding these

steels are the formation of a hardened zone in the

weld area, and, if suitable precautions are not taken,

the occurrence in this zone of under-bead cracks.

Hardened zone and under-bead cracks in the weld

area may be reduced by using the correct electrodes,

preheating, using higher current settings, using

larger electrodes sizes, short runs for larger electrode

deposits or tempering in a furnace.

Manganese Steels

The effect on manganese steel of slow cooling from

high temperatures is to embrittle it. For this reason it

is absolutely essential to keep manganese steel cool

during welding by quenching after each weld or skip

welding to distribute the heat.

Cast Iron

Most types of cast iron, except white iron, are

weldable. White iron, because of its extreme

brittleness, generally cracks when attempts are made

to weld it. Trouble may also be experienced when

welding white-heart malleable, due to the porosity

caused by gas held in this type of iron.

Copper and Alloys

The most important factor is the high rate of heat

conductivity of copper, making pre-heating of heavy

sections necessary to give proper fusion of weld and

base metal.

Types of Electrodes

Arc Welding electrodes are classified into a number

of groups depending on their applications. There are

a great number of electrodes used for specialized

industrial purposes which are not of particular interest

for everyday general work. These include some low

hydrogen types for high tensile steel, cellulose types

for welding large diameter pipes, etc. The range of

electrodes dealt with in this publication will cover the

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