SELECTION
OF WELDING ELECTRODES &
In fabrication area the
selection of electrodes plays major role, the electrodes selection depends on,
1) Type
of joint.
2) Thickness
and fit-up of joint.
3) Position of welding.
4) Composition of parent metal.
5) Requirements of weld joint.
6) Other parametrers.
6) Other parametrers.
A) Inspection of electrodes
During inspection of electrodes
required to check coating cracks, damages cracks, flux remove, wetness etc., require
to check batch no. manufacturing date & batch certificate and check the
certificate with actual physical material, review of appropriate test
certificate also plays major role.
B) Handling & storage of
electrodes
Container which used for
electrodes which correct and proper condition, its required to protect containers
from rain and water stay away from SO2 gas. Open container only when electrodes
to be used. Keep away the containers from walls/floors and containers should be
dry. Baking of electrodes at different
temperature depends on the application and material and service for which we
used, its dangerous to stored electrodes at higher temperature for long period.
Consumables
inserts.
Generally, the consumables used where
high quality of weld and minimum repaired required. Consumables usually used in
pipe joints also used in pressure vessels. In GTAW process consumables selection
plays major role because the quality and perfectness of weld joint is totally depending
on the purity of insert and proper supply of insert. Insert classified on the
basis of chemical composition.
Electrodes are mainly classified into 5 main groups:
1) Cast iron
2) Mild steel - majority of welding
3) Special alloy steel
4) High carbon steel
5) Non ferrous - example Aluminum, Copper, & brass.
Electrodes size based on diameters, each size of electrode have certain current range the welding current increases with size of electrode.
Different sizes of electrodes available in market as 1.6 mm 2.0 mm 2.5 mm 3.15 mm 4.0 mm 5.0 mm 6.0 mm 6.3 mm 8.0 mm & 10.0 mm.
Generally electrodes manufacturing length in range between 250 mm to 450 mm.
One thing noted that, Electrode size means the size of the wire, not overall size of the rod.
Electrodes are mainly classified into 5 main groups:
1) Cast iron
2) Mild steel - majority of welding
3) Special alloy steel
4) High carbon steel
5) Non ferrous - example Aluminum, Copper, & brass.
Electrodes size based on diameters, each size of electrode have certain current range the welding current increases with size of electrode.
Different sizes of electrodes available in market as 1.6 mm 2.0 mm 2.5 mm 3.15 mm 4.0 mm 5.0 mm 6.0 mm 6.3 mm 8.0 mm & 10.0 mm.
Generally electrodes manufacturing length in range between 250 mm to 450 mm.
One thing noted that, Electrode size means the size of the wire, not overall size of the rod.
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