Welding Technique; Electrode Selection - Linde BOC Smootharc Advance MIG 425R Operating Manual

44 BOC Smootharc Advance III MIG 425R & 555R Operating manual

12.3 Welding Technique

Successful welding depends on the following factors:
→ selection of the correct electrode
→ s election of the correct size of the electrode for the job
→ correct welding current
→ correct arc length
→ correct angle of electrode to work
→
correct travel speed
→
correct preparation of work to be welded.

12.4 Electrode Selection

As a general rule the selection of an electrode is straight forward, in that it is
only a matter of selecting an electrode of similar composition to the parent
metal. It will be found, however, that for some metals there is a choice of
several electrodes, each of which has particular properties to suit specific
classes of work. Often, one electrode in the group will be more suitable for
general applications due to its all round qualities.
The following table shows just a few of the wide range of electrodes
available from BOC with their typical areas of application.
For example, the average welder will carry out most fabrication using mild
steel and for this material has a choice of various standard BOC electrodes,
each of which will have qualities suited to particular tasks. For general mild
steel work, however, BOC Smootharc 13 electrodes will handle virtually
all applications. BOC Smootharc 13 is suitable for welding mild steel in all
positions using AC or DC power sources. Its easy-striking characteristics
and the tolerance it has for work where fit-up and plate surfaces are not
considered good make it the most attractive electrode of its class. Continuous
development and improvement of BOC Smootharc 13 has provided in-built
operating qualities which appeals to the beginner and experienced operator
alike.
Electrodes and Typical Applications
Name AWS
Class.
BOC Smootharc 13 E6013
BOC Smootharc 24 E7024
BOC Smootharc 18 E7018-1 A premium quality all positional
BOC Smootharc S 308L E308L
BOC Smootharc S 316L E316L
BOC Smootharc S 309L E309L
Application
A premium quality electrode for general
structural and sheet metal work in all
positions including vertical down using
low carbon steels
An iron powder electrode for high
speed welding for H-V fillets and flat
butt joints. Medium to heavy structural
applications in low carbon steels
hydrogen controlled electrode for
carbon steels in pressure vessel
applications and where high integrity
welding is required and for free-
machining steels containing sulphur
Rutile basic coated low carbon
electrodes for welding austenitic
stainless steel and difficult to weld
material
Rutile basic coated low carbon electrode
for welding mild steel to stainless steel
and difficult to weld material