Classification and Designation of Welding Filler Materials

Standard EN 12072

The standard EN12072 specifies requirements for classification of wire electrodes, wires and rods for gas shielded metal arc welding, gas tungsten arc welding, plasma arc welding and submerged arc welding of stainless and heat resisting steels. The classification of the wire electrodes, wires and rods is based on their chemical composition.

For stainless steel welding consumables there is no unique relationship between the product form (wire electrode, wire or rod) and the welding process used (gas shielded metal arc welding, gas tungsten arc welding, plasma arc welding or submerged arc welding). For this reason the wire electrodes, wires or rods can be classified on the basis of any of the above product forms and can be used as appropriate, for more than on of the above processes.

A wire electrode, wire or rod is classified in accordance with its chemical composition. The classification is divided into two parts, as follows:

1. The first part gives a symbol indicating the product/process to be identified, as follows:
   G = Gas shielded metal arc welding.
   W = Gas tungsten arc welding.
   P = Plasma arc welding.
   S = Submerged arc welding.
   
2. The second part gives a symbol indicating the chemical composition of the wire electrode, wire or rod. This grade has the symbol 25 20 Mn and is a heat resisting type.

The influence of the shielding gas or flux on the chemical composition of the all-weld metal is considered. Differences between the chemical composition of the all-weld metal and the wire electrode, wire or rod can occur.

Proof and tensile strength of the weld metal made by this grade is expected to conform with the minimum requirements contained in the mechanical properties table. Elongation and impact properties of the weld metal can deviate from the minimum values specified for the corresponding parent metal as a result of variations in the microstructure.

Standard EN 758

This specification specifies the requirements for classification of tubular cored electrodes in the as-welded condition for metal arc welding, with or without a gas shield, of non alloy and fine grain steels with a minimum yield strength of up to 500 N/mm. One tubular cored electrode can be tested and classified with different gases.

The designation contains 6 compulsory and 2 optional parts.

Compulsory Section:

The first part, T, is a symbol denoting that it is a tubular cored electrode used in the metal arc welding process.

The second part, 50, is a symbol denoting the yield strength, tensile strength and elongation of the all-weld metal in the as-welded condition.

The third part is a symbol denoting the temperature at which minimum average impact energy of 47 J of all-weld metal can be achieved, as follows:
Z = No requirement
A = +20°C
0 = 0°C
2 = -20°C
3 = -30°C
4 = -40°C
5 = -50°C
6 = -60°C

The fourth part, Z, is a symbol indicating the chemical composition of all-weld metal. The symbol Z denotes any agreed composition other than those grades already contained in the specification.

The fifth part is a symbol indicating the type of tubular cored electrode relative to its core composition and slag characteristics, as follows:
R = Rutile, slow freezing slag, single and multiple pass types of weld, requiring a shielding gas.
P = Rutile, fast freezing slag, single and multiple pass types of weld, requiring a shielding gas.
B = Basic, single and multiple pass types of weld, requiring a shielding gas.
M = Metal powder, single and multiple pass types of weld, requiring a shielding gas.
V = Rutile or basic/fluoride, single pass type of weld, not requiring a shielding gas.
W = Basic/fluoride, slow freezing slag, single and multiple pass types of weld, not requiring a shielding gas.
Y = Basic/fluoride, fast freezing slag, single and multiple pass types of weld, not requiring a shielding gas.
Z = Other types.

The sixth part is a symbol indicating the type of shielding gas as follows:
M = mixed gases: EN 439 - M2 but without helium.
C = EN 439 - C1, carbon dioxide
N = This symbol shall be used for tubular cored electrodes without a gas shield.

Optional Section (the next two parts have not been included in the designation for this grade):

The seventh part gives a symbol for the welding position as follows:
1 = all positions;
2 = all positions, except vertical down;
3 = flat butt weld, flat fillet weld, horizontal-vertical fillet weld;
4 = flat butt weld, flat fillet weld;
5 = vertical down and positions according to symbol 3.

The eighth part gives a symbol indicating the hydrogen content of deposited metal as follows:
Symbol Hydrogen content ml/100 g deposited metal
H5 5 maximum
H10 10 maximum
H15 15 maximum

Standard EN 499

This specification specifies the requirements for classification of covered electrodes and deposited metal in the as-welded condition for manual metal arc welding of non alloy and fine grain steels with a minimum yield strength of up to 500 N/mm in the welded condition.

The designation contains 5 compulsory and 3 optional parts.

Compulsory Section: The first part, E, is a symbol denoting that it is a covered electrode used in the manual metal arc welding process.

The second part, 38, is a symbol denoting the yield strength, tensile strength and elongation of the all-weld metal in the as-welded condition.

The third part is a symbol denoting the temperature at which minimum average impact energy of 47 J of all-weld metal can be achieved, as follows:
Z = No requirement
A = +20°C
0 = 0°C
2 = -20°C
3 = -30°C
4 = -40°C
5 = -50°C
6 = -60°C

The fourth part, 1Ni, is a symbol indicating the chemical composition of all-weld metal.

The fifth part is a symbol indicating the type of electrode covering as follows:
A = acid covering
C = cellulosic covering
R = rutile covering
RR = rutile thick covering
RC = rutile-cellulosic covering
RA = rutile-acid covering
RB = rutile-basic covering
B = basic covering

Optional Section (the next three parts have not been included in the designation for this grade):

The sixth part gives a symbol for the weld metal recovery and type of current as follows:
Symbol % weld metal recovery Type of current
1 less than or equal to 105 a.c. + d.c.
2 less than or equal to 105 d.c.
3 over 105 up to and inc.125 a.c. + d.c.
4 over 105 up to and inc.125 d.c.
5 over 125 up to and inc.160 a.c. + d.c.
6 over 125 up to and inc.160 d.c.
7 over 160 a.c. + d.c.
8 over 160 d.c.

The seventh part gives a symbol for welding position as follows:
1 = all positions
2 = all positions, except vertical down
3 = flat butt weld, flat fillet weld, horizontal vertical fillet weld
4 = flat butt weld, flat fillet weld
5 = vertical down and positions according to symbol 3

The eighth part gives a symbol indicating the hydrogen content of all-weld metal as follows:
Symbol Hydrogen content ml/100 g all-weld metal
H5 5 maximum
H10 10 maximum
H15 15 maximum