F7P2-EM12 F6A0-EL12 F7A2-EM12
op129 ama op129

Flux for Submerged Arc welding of General Struct

 AMA OP129

EN 760: SA CS 1 77AC
DIN 32 522: B CS 1 77 AC 10 M
AWS/ASME: F7P2-EM12    F6A0-EL12    F7A2-EM12

Application and properties:

Agglomerated Calcium-Silicate type flux for welding general structural steels, pressure vessel steels, pipe steels as well as fine grain structural steels. It produces a mean silicon pick-up and when used with wire electrodes, 50-14, 50-15, 50-11, 50-12 also a manganese pick-up. The neutral point for manganese is at approximately 2%. AMA OP 129 can therefore be combined with wire electrodes having a low manganese content.
It is particularly for twin-wire, tandem and multi-wire at high speeds. AMA OP 129 is likewise suited for welding from both sides in one pass. For increased weld metal toughness, wire electrode containing molybdenum 50-14 should be preferably used. AMA OP 129 can be used on either DC or AC up to 1000A (in single wire welding).
Slag removal is easy. The resulting slag is short, i.e., girth seams on work pieces having a small diameter can be welded without the danger of the slag running off.

Damp flux shall be redried by baking at 300°C – 350°C
Grain size in according to DIN 32 522:2-20

Main Constituents:

SiO2+TiO2 CaO+MgO Al2O3+MnO CaF2
40% 20% 25% 10%

Basicity to boniszewskii: ~1.0

Metallurgical behavior:

Pick-up and burn-off the alloying elements Si and Mn as a function of the alloy
Content of the wire electrode, DVS Merkblatt 0907, part 1

All -Weld metal analysis (typical values):

With Wire Electrode Weight %
DIN/EN C Si Mn Mo
50-11 S1 0.04-0.08 0.3-0.7 0.8-1.3 -
50-12 S2 0.04-0.08 0.3-0.7 1.1-1.7 -
50-15 S3 0.04-0.08 0.3-0.7 1.3-1.9 -
50-14 S2Mo 0.04-0.08 0.3-0.7 1.1-1.7 0.5

Mechanical properties of all-weld metal (typical values):

With Wire Electrode Heat Treatment Tensile Strength
(N/mm )
Yield Strength
(N/mm )
Elongation
Lo=5d %
Impact energy (Joule)
ISO -V
+20°C          ±0°C        -20°C        -40°C
50-11 As Welded 420-500 > 360 > 24 >100           >60           >30           -
50-12 As Welded 520-620 > 400 > 24 >100           >80           >50           -
50-15 As Welded 550-650 > 460 > 24 >130        >100        >70        >50
50-14 As Welded 600-700 > 480 > 20 >90           >50           >35           -

Application:

Materials Multi pass joint welding Welding from both sides in one pass
General structural steels With wire electrode With wire electrode
St 37-2, USt 37-2, RSt 37-2 50-11 50-11,50-12
St37-2, St44-2, St44-3, St52-3 50-11 50-11,50-12
Pipe Steels With wire electrode With wire electrode
StE210.7, StE240.7 , St290.7 50-11 50-12,50-14
StE 320.7, StE 360.7 50-12 50-12,50-14
St 35.0, St 35.4, St 35.8 50-11 50-12,50-14
St 45, St 45.4, St 45.8 50-12 50-12,50-14
St 52, St 52.4 50-12 50-12,50-14
X42 50-11 50-12,50-14
X46, X52, X56 50-12 50-12,50-14
X60, X65, X70 50-14 50-12,50-14
Boiler plates With wire electrode With wire electrode
H I, H II 50-11 50-12,50-14
17Mn 4, 19Mn 5 50-12 50-12,50-14
Fine grain structural steels With wire electrode With wire electrode
StE 255, WStE 255 TStE 255*** 50-12* 50-12,50-14
StE 285, WStE 285 TStE 285*** 50-12* 50-12,50-14
StE 315, WStE 315 TStE 315*** 50-12* 50-12,50-14
StE 355, WStE 355 TStE 355*** 50-12*,50-15** 50-12,50-14
StE 420, WStE 420 TStE 420*** 50-15** 50-12
StE 460, WStE 460 TStE 460*** 50-15** 50-12

For welding from both side in one pass, especially in multi-wire welding 50-14 wire electrode should be used because of the fine-grain formation caused by molybdenum.
* At service temperatures down to -20°C
** At service temperatures down to -40°C