F8A8-EA4 F8A8-EF1 F8A8-EH12K F7A5-EM12 F8P8-EA4 F8A2-EB2 F7P8-EH12K F7A5-EM12K F8P2-EB2 F8A8-EH14 F8A4-EA2 F7A6-EM13K F9A8-EF1 F7P5-EA2 F7P6-EM13K
op121tt ama op121tt

Flux for Submerged Arc welding of General Struct

AMA OP121TT

EN 760: SA FB 1 55 AC H5
DIN 32 522: B FB 1 55 AC 10MHP5
AWS/ASME: F8A8-EA4        F8A8-EF1        F8A8-EH12K        F7A5-EM12        F8P8-EA4        F8A2-EB2        F7P8-EH12K      F7A5-EM12K        F8P2-EB2        F8A8-EH14        F8A4-EA2      F7A6-EM13K        F9A8-EF1        F7P5-EA2        F7P6-EM13K

Type/ Characteristics:

Agglomerated fluoride-basic type flux, preferably used for high strength fine grain structural steels, as well as cryogenic steels and steels resistant to ageing. Owning its neutral behavior as regards pick-up and burn-out of silicon and manganese, wire electrodes having higher percentages of Si and Mn (e.g. 50-27, 50-57) should be used.
AMA-OP121TT is particularly suited for tandem and multi-wire welding. On the strength of COD tests made with, 50-57 wire electrodes, this flux is suitable to be employed for welding offshore components. The weld metal produced in combination with corresponding wire electrodes, meets high toughness requirements at cryogenic temperatures.
AMA-OP121TT produces a short slag, i.e. girth seams of components having a small diameter can be welded without the danger of the slag running off. It produces uniform welds without undercut.
AMA-OP121TT can be used on either DC (positive) or AC up to approximately 1000A.
Damp flux shall be redried by baking at 300°C – 350°C
Grain size according to DIN 32 522:2-20

Main Constituents:

SiO2+TiO2 CaO+MgO Al2O3+MnO CaF2
15% 40% 20% 25%

Basicity to boniszewskii: ~3.1

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 %
AMA Trade Name DIN/EN C Si Mn Mo Cr Ni
50-12 S2 0.05-0.08 0.15-0.25 0.7-1.0 - - -
50-15 S3 0.05-0.08 0.15-0.25 1.0-1.4 - - -
50-57 EH12K 0.05-0.08 0.20-0.40 1.4-1.9 - - -
50-14 S2Mo 0.05-0.08 0.15-0.25 0.7-1.0 0.5 - -
50-17 S3Mo 0.05-0.08 0.15-0.25 1.0-1.4 0.5 - -
50-22 S2crMo1 0.05-0.08 0.20-0.30 0.7-1.0 0.5 1 -
50-23 S2crMo2 0.05-0.08 0.20-0.30 0.5-0.8 1.0 2.2 -
50-24 S2Ni1 0.05-0.08 0.25-0.40 1.0-1.3 - - 1.0
50-25 S2Ni2 0.05-0.08 0.20-0.30 0.7-1.0 - - 2.0
50-25 S3Ni1Mo 0.05-0.08 0.20-0.40 1.3-1.6 -0.5 - 1.0

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

With Wire Electrode Heat Treatment Tensile Strength
(N/mm )
Yield Strength
(N/mm )
Elongation
Lo=5d%
50-12 As Welded 450-550 > 360 > 28
50-15 As Welded 530-630 > 430 > 25
50-57 As Welded 540-640 > 450 > 24
50-14 As Welded 580-680 > 500 > 20
50-17 Tempered(1) 600-700 > 530 > 18
50-22 Tempered(1) 530-630 > 380 > 24
50-22 Norm+Temp(2) 430-530 > 310 > 30
50-23 Tempered(3) 550-650 > 450 > 22
50-23 Norm+Temp(4) 520-620 > 400 > 22
50-24 As Welded 500-600 > 420 > 24
50-24 Stress relived 480-580 > 380 > 26
50-25 As Welded 550-650 > 450 > 24
50-25 Stress relived 500-600 > 430 > 26
50-21 As Welded 650-750 > 540 > 20
50-21 Stress relived 630-730 > 540 > 22
 
Heat Treatment Impact energy (Joule) ISO -V 20°C       ±0°C       -20°C       -40°C       -60°C         -80°C
50-12 As Welded >180      >160       >100            -               -                 -
50-15 As Welded >180     >160        >100        >35              -                 -
50-57 As Welded >200     >180        >140        >100         >70               -
50-14 As Welded >140     >120        >100        >70             >50             -
50-17 As - Welded >140     >120        >100        >70             >50             -
50-22 Tempered(1) >200     >150            -               -                  -               -
50-22 Norm+Temp(2) >200     >200            -               -                 -                -
50-23 Tempered(3) >140    >100             -               -                 -                 -
50-23 Norm+Temp(4) >140     >90              -               -                 -                 -
50-24 As Welded >150     >130        >100         >70            >50             -
50-24 Stress relived >170     >140        >110         >90            >70             -
50-25 As Welded >160     >140        >120         >100         >70         >50
50-25 Stress relived 160       >140        >120         >90           >70             -
50-21 As Welded >150     >120        >90           >70            >50             -
50-21 Stress relived 160       >140        >120         >90            >70             -
 

1)tempered: 700°C -720°C
2)norm+temp: 920°C/air + 700°C -720°C
3)tempered: 730°C -750°C
4)norm+temp: 940°C/air + 730°C -750°C

Application:

Materials Multi pass joint welding
Fine grain structural steels With wire electrode
StE 255, WStE 255 50-12,50-15
StE 285, WStE 285 50-12,50-15
StE 315, WStE 315 50-12.50-15
StE 355, WStE 355 50-12,50-15
StE 380, WStE 380 50-15.50-57
StE 420, WStE 420 50-15,50-57
StE 460, WStE 460 50-57
StE 500, WStE 500 50-24(1),50-21(2)
TStE 255, EStE 255 50-24,50-15,50-57(3)
TStE 285, EStE 285 50-24,50-15,50-57(3)
TStE 315, EStE 315 50-24,50-15,50-57(3)
TStE 355, EStE 355 50-24,50-15,50-57(3)
TStE 380, EStE 380 50-24,50-15,50-57(3)
TStE 420, EStE 420 50-24,50-15,50-57(3)
TStE 460, EStE 460 50-57
TStE 500, EStE 500 50-57(1),50-21(2)
Creep resistant steels With wire electrode
15 Mo3 50-14,50-17
13 Cr Mo44 50-22
10 Cr Mo9 10 50-23
Cryogenic Steels With wire electrode
10 Ni 14(4) 50-25
TTSt 35 N, TTSt 35 V 50-25
TTSt 41 N, TTSt 41 V 50-25
Non-ageing steels -
ASt 35, ASt 41 50-15
ASt 45, ASt 52 50-15

1)only thinner plates
2)Also for stress-relived condition
3)Observe minimum temperature of -40°C
4)Lowest service temperature -80°C
Approval : LRS