WELDING CONSUMABLES

WELDING CONSUMABLES

There are 3-types of electrode

• Cellulosic
• Rutile
• Basic

CELLULOSIC ELECTRODE

• It cannot be baked
• It has forceful arc
• Risk of hydrogen cracking
• High toughness at low temperature cannot be achieved
• Used for root runs
• Used for stove pipe welding.

RUTILE ELECTRODE

• It cannot be baked
• Risk of hydrogen cracking
• Smooth &stable arc
• High toughness at low temperature cannot be achieved
• Used for steel thickness ≤ 13mm

BASIC ELECTRODE

• Can be baked upto 350 degree centigrade
• It has got good sub-zero toughness upto -90 degree centigrade
• Surface profile will be convex
• Slag removal require more effort
• It is used to avoid hydrogen cracking.

ELECTRODE DESIGNATION

E 46 3 1Ni D 5 4 H5

E = Covered electrodes

46 = Toughness / Tensile & Yield Strength

3 = Impact energy

1Ni = Chemical Composition

D = Type of coating

5 = Type of current & Metal recovery %

4 = Welding Position

H5 = Hydrogen content

The first five parts of code are important and compulsory comprising

E = Covered electrodes

46 = Tensile & Yield Strength

3 = Impact energy

1Ni = Chemical Composition

D = Type of coating

MCQ IMPORTANT POINTS

1. The type of electrode used for ‘stove pipe’ welding for overland pipeline construction is Cellulosic.
2. The chemical composition of the weld metal is controlled by the additions in the flux of electrode.
3. A low hydrogen will have basic type of covering.
4. A typical baking temperature range of basic coated electrode is 350 degree centigrade.
5. A basic covering electrode gives high weld metal toughness at -50 degree centigrade.