Flux for Submerged Arc welding of General Struct

AMA AP720

Standards: DIN 32 522 : B FB 6 55455 AC 8 MHP 5
EN 760 : SA FB 2 55 AC

Type/ Characteristics:
Special agglomerated fluoride-basic type flux for welding austenitic stainless steels in combination with wire electrode according to DIN 8556. As to carbon content of the weld metal, AMA-AP720 is strictly neutral, so that, using suitable wire electrodes steels having extra low carbon content can be safely welded. It has no chromium compensation which is of importance if certain ferrite content in the weld deposit must be observed. Its metallurgical behavior as regards silicon and Manganese burn off will take place when using wire electrodes having a high Manganese content. AMA-AP720 is designed for welding thick sections. It is a hydrogen controlled flux deposition low hydrogen weld metal.
AMA-AP720 is particularly suited to be used in tandem and multi-wire welding.
It produces smooth and finely rippled weld beads merging into the base metal without undercut.
AMA AP 720 can be used on DC (positive) or AC up to 800C.
Damp flux shall be redried by backing at 300 350 c.
Grain size according to DIN 32 522:2-20.

Main Constituents:

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

Basicity as to boniszewskii: ~2.7

All -Weld metal analysis (typical values):

With Wire electrode Weight - %
AMA Trade Name DIN/EN C Cr Ni Mo Nb N
30-51 ER308L <0.03 >18 >9 - - -
30-52 ER347 <0.07 >18 >9 - >8×C -
30-53 ER316L <0.03 >18 >10 2.5 - -
30-54 ER318 <0.07 >18 >10 2.5 >8×C -
30-56 <0.03 20 16 3.0 - 0.15
30-55 <0.03 23 9 3.0 - 0.15
30-57 <0.15 22 12 - - -
30-58 <0.03 21 >60 9.0 -3.5 -

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

With Wire Electrode Proof stress %0.2
( N/mm )
Proof stress %0.1
( N/mm )
Tensile Strength
( N/mm )
Elongation
Lo = 5d (%)
Impact energy (Joule)
ISO - V
20°C+
30 – 51 > 320 > 350 > 550 > 35 > 75
30 – 52 > 350 > 370 > 575 > 30 > 65
30 – 53 > 320 > 350 > 550 > 30 > 75
30 – 54 > 350 > 370 > 600 > 30 > 65
30 – 56 > 380 > 410 > 600 > 30 > 120
30 – 55 > 450 > 500 > 650 > 25 > 100
30 – 57 > 320 > 350 > 650 > 30 > 75
30 – 58 > 400 > 420 > 680 > 30 > 75

Application: Welding of austenitic stainless Cr Ni steel, particularly thick sections.

Materials Material-No With wire electrode Material-No
X 2 Cr Ni 1911 1.4306 30 - 51 1.4316
X 5 Cr Ni 1810 1.4301 30 - 51 1.4316
X 6 Cr Ni Ti 1810 1.4541 30 - 52 1.4551
X 5 Cr Ni Nb 189 1.4543 30 - 52 1.4551
X 6 Cr Ni Nb 1810 1.4550 30 - 52 1.4551
X 12 Cr Ni Ti 189 1.4878 30 - 52 1.4551
X 2 Cr Ni Mo 17132 1.4404 30 - 53 1.4430
X 2 Cr Ni Mo 18142 1.4435 30 - 53 1.4430
X 5 Cr Ni Mo 17122 1.4401 30 - 53 1.4430
X 6 Cr Ni Mo Ti 17122 1.4571 30 - 54 1.4576
X 10 Cr Ni Mo Ti 1812 1.4573 30 - 54 1.4576
X 6 Cr Ni Mo Nb 17122 1.4580 30 - 54 1.4576
X 10 Cr Ni Mo Nb 1812 1.4583 30 - 54 1.4576
X 2 Cr Ni Mo N 22 5 1.4462 30 - 55 ~1.4462
X 15 Cr Ni Si N 20 12 1.4828 30 - 57 1.4829
X 12 Cr Ni Ti N 18 9 1.4878 30 - 57 1.4828
X 2 Cr Ni 18 9 1.4306 30 - 56* 1.4455
X 5 Cr Ni 18 10 1.4301 30 - 56* 1.4455
X 6 Cr Ni Ti 18 10 1.4541 30 - 56* 1.4455
X 5 Cr Ni Nb 18 9 1.4543 30 - 56* 1.4455
X 6 Cr Ni Nb 18 19 1.4550 30 - 56* 1.4455
X 12 Cr Ni Ti 18 9 1.4878 30 - 56* 1.4455
X 2 Cr Ni Mo 17 13 2 1.4404 30 - 56* 1.4455
X 2 Cr Ni Mo 18 14 2 1.4435 30 - 56* 1.4455
X 5 Cr Ni Mo 17 12 2 1.4401 30 - 56* 1.4455
X 6 Cr Ni Mo Ti 17 12 2 1.4571 30 - 56* 1.4455
X 10 Cr Ni Ti Mo 18 12 1.4573 30 - 56* 1.4455
X 6 Cr Ni Mo Nb 17 12 2 1.4580 30 - 56* 1.4455
X 10 Cr Ni Mo Nb 18 12 1.4583 30 - 56* 1.4455

*If weld metal is required to be fully austenitic

Materials Material-No With wire electrode Material-No
X 8 Ni 9 1.5662 30 - 56 1.4455
10 Ni 14 1.5637 30 - 56 1.4455
12 Ni 19 1.5680 30 - 56 1.4455
  • AMA AP 720 + 30 -56 is out standing for joining unalloyed and low alloy steels to high alloy steels.