Class: ER309LMo

AWS: A5.9

Conforms to Certification: AWS A5.9      ASME SFA A5.9

Weld Process Used for Tig (GTAW)

AWS Chemical Composition Requirements
C = 0.03 max
Cr = 23.0 – 25.0
Ni = 12.0 – 14.0
Mo = 2.0 – 3.0
Mn = 1.0 – 2.5
Si = 0.30 – 0.65
P = 0.03 max
S = 0.03 max
Cu = 0.75 max

Available Sizes
.030 x 36
.035 x 36
.045 x 36
1/16 x 36
3/32 x 36
1/8 x 36
3/16 x 36
5/32 x 36

Application
This classification has a low carbon content of 0.03% max. ER309LMO is usually needed for the first layer to achieve low carbon contents in other layers with ER316L or ER317L.

Deposited Chemical Composition % (Typical)
C = 0.02	Mo = 2.40	P = 0.012
Cr = 23.75	Mn = 1.75	S = 0.010
Ni = 13.10	Si = 0.40

 

Mechanical Properties (R.T.)
Yield Strength	58,000 psi
Tensile Strength	85,000 psi
Elongation	36%
Reduction of Area	55%

Deposited All Weld Metal Properties
Data is typical for ER309LMo weld metal deposited by Tig using 100% Argon as the shielding gas.

Recommended Welding Parameters
GTAW “Tig Process”
Wire Diameter	Amps DCSP	Volts	Shielding Gas
.035	60-90	12-15	Argon 100%
.045	80-110	13-16	Argon 100%
1/16	90-130	14-16	Argon 100%
3/32	120-175	15-20	Argon 100%

Note: Parameters for tig welding are dependent upon plate thickness and welding position.
Other shielding Gases may be used for Tig welding. Shielding gases are chosen taking Quality, Cost, and Operability into consideration.