ER312

Class: ER312
AWS: A5.9

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

Weld Process Used for Mig: (GMAW) and Submerged Arc (SAW)

AWS Chemical Composition Requirements
C = 0.15 max
Cr = 28.0 – 32.0
Ni = 8.0 – 10.5
Mo = 0.75 max
Mn = 1.0 – 2.5
Si = 0.30 – 0.65
P = 0.03 max
S = 0.03 max
Cu = 0.75 max

Available Sizes

Diameter  X Spool Sizes Diameter X Coil Sizes
.025 x 2#, 10#, 25# 1/16 x 60# & mill coil
.030 x 2#, 10#, 25#, 30#, 33# 5/64 x 60# & mill coil
.035 x 2#, 10#, 25#, 30#, 33# 3/32 x 60# & mill coil
.045 x 2#, 10#, 25#, 30#, 33# 1/8 x 60# & mill coil
1/16 x 10#, 25#, 30#, 33# 3/16 x 60# & mill coil
5/32 x 60# & mill coil

Application
ER312 is used to weld cast alloys of similar composition and is used to weld dissimilar metals and weld overlays. This alloy has very high ferrite. When welding similar cast alloys, limit welding to two or three layers only.

Deposited Chemical Composition % (Typical)
C = 0.11 Mo = 0.15 P = 0.013
Cr = 29.00 Mn = 1.60 S = 0.013
Ni = 9.25 Si = 0.40
Mechanical Properties (R.T.) 
Yield Strength 75,000 psi
Tensile Strength 105,000 psi
Elongation 25%
Reduction of Area 30%

Deposited All Weld Metal Properties
Data is typical for ER312 weld metal deposited by Mig using Argon + 2% oxygen as the shielding gas.  Data on sub-arc is not presented, as sub-arc is dependent on the type of flux used.

Recommended Welding Parameters

GMAW “Mig Process” Reversed Polarity
Wire Diameter Wire Feed Amps Volts Shielding Gas Gas CFH
Short Arc Welding .030 13-26 40-120 16-20 Argon+2% O2 25
.035 13-26 60-140 16-22 Argon+2% O2 25
Spray Arc Welding .035 20-39 140-220 24-29 Argon+2% O2 38
.045 16-30 160-260 25-30 Argon+2% O2 38
1/16 10-16 230-350 27-31 Argon+2% O2 38

Other shielding Gases may be used for Mig welding. Shielding gases are chosen taking Quality, Cost, and Operability into consideration

Recommended Welding Parameters

SAW “Submerged Arc Welding Process” Reversed Polarity Suggested
Wire Diameter Amps Volts
3/32 250-450 28-32
1/8 300-500 29-34
5/32 400-600 30-35
3/16 500-700 30-35

Both Agglomerated and fused fluxes can be used for submerged arc welding.

Note: The chemical composition of the flux mainly affects the chemistry of the weld metal and consequently its corrosion resistance and Mechanical properties.