Class: ER420

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 = 0.25 – 0.40
Cr = 12.0 – 14.0
Ni = 0.60 max
Mo = 0.75 max
Mn = 0.60 max
Si = 0.50 max
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#	5/64 x mill coil
.030 x 2#, 10#, 25#, 33#	3/32 x 60# & mill coil
.035 x 2#, 10#, 25#, 33#	1/8 x 60# & mill coil
.045 x 2#, 10#, 25#, 33#	3/16 x 60# & mill coil
1/16 x 10#, 25#, 33# also 60#	5/32 x 60# & mill coil

Application
This alloy is often used for surfacing applications which call for superior resistance to abrasion. It requires preheat and inter-pass temperatures of not less than 400ºF, followed by slow cooling. Post weld heat treatment is used to temper the weld deposit.

Deposited Chemical Composition % (Typical)
C = 0.29	Mo = 0.10	P = 0.014
Cr = 13.5	Mn = 0.45	S = 0.008
Ni = 25	Si = 0.48

 

Mechanical Properties (R.T.)
Yield Strength	120,000psi
Tensile Strength	145,000psi
Elongation	45%

Deposited All Weld Metal Properties
Data is typical for ER420 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.

Note: Mechanical properties are greatly influenced by changes in welding parameters such as preheat and inter-pass temperatures.

 

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.