39
the operating conditions of the structure, as well as the
consequences of possible damage and treatments after
welding. Concerning loads on the structure, both loads
at the pile installation stage and those occurring during
operation must be considered.
7.5.3 Qualification of Welders
The welders must have passed the test indicated in
Standard EN ISO 9606-1 (Qualification test of welders.
Fusion Welding. Part 1: Steels). The welding contractor
must ensure that the welders carry valid certificates
Table 30. Selection of welding consumable
Steel
grade
Mechanical properties of weld metal
(EN ISO 2560 and 18275 covered electrodes and EN ISO 14341, 17632 and 18276 for tubular cored electrodes)
Yield strength
1
Impact strength
2
Covered electrode, examples
Tubular cored electrode, examples
S355J2H
35
2
ESAB OK 48.00
TRI-MARK TM-770, ESAB OK Tubrod 15.14
S440J2H
46
2
ESAB OK 55.00, ESAB OK 48.08
TRI-MARK TM-770, ESAB OK Tubrod 15.14
S550J2H
55
2
ESAB OK 74.78
TRI-MARK TM-881 K2, ESAB Dual Shield 55
X60
42
2
ESAB OK 48.00
TRI-MARK TM-770, ESAB OK Tubrod 15.14
X70
50
2
ESAB OK 74.78
TRI-MARK TM-881 K2, ESAB Filarc PZ 6138
1)
Yield srength values of all-weld metal
2)
Testing temperature of 47 J impact energy of all-weld metal: 0=0 °C, 2=-20 °C.
35 = minimum yield strength: 350 MPa
42 = minimum yield strength: 420 MPa
46 = minimum yield strength: 460 MPa
50 = minimum yield strength: 500 MPa
55 = minimum yield strength: 550 MPa
of qualification. Qualification tests must correspond to
the requirements of the work. Factors to be considered
include welding procedure, type of joint, steel grade,
material thickness, external pipe diameter, and welding
position as indicated in the standard. Qualification test
welds are normally to be made on pipe. Test welds on
plate are acceptable with pile diameters over 500 mm.
In the case of manual metal arc welding with covered
electrode, the welder’s competence can be ascertained,
for example, by a single-sided test weld on pipe without
backing.
Table 29. Example of qualification test for manual metal arc welder
EN ISO 9606-1: 111 T BW W01 B t10.0 D168 PC ss nb
Explanation:
111
Manual metal arc welding
T
Pipe
BW
Butt splice
2.1
Group of basic materials according to CEN ISO/TR 15608 and CEN ISO/TR 20172:2009
(qualifies for SSAB steel grades S355 to S460 and X60)
B
Base-coated electrode
t10.0
Weld test on pipe of 10 mm wall thickness, qualifies for thicknesses t = 3 to 20 mm
D168
Test on pipe 168 mm in diameter, qualifies for diameters D
≥
84 mm
PC
Welding position PC, pipe in upright position, qualifies also for splice welding
ss
Single side welding
nb
No backing (qualifies also for welding with backing)
Welding of steel grades S550J2H and X70 requires passing a qualification test with the steel of the group of basic materials 2.2