We are welding 4130 low alloy steel, which TIG filler wire should we use?

AISI 4140 is a widely used high-strength, low alloy, structural steel. It's also commonly used alongside AIS 4130 steel. These are Cr-Mo steels: the 40 and 30 indicate 0.40 and 0.30 typical carbon content respectively. These alloys are susceptible to hydrogen-embrittlement and require special care when welding.

For most welding applications, ER80S-D2 is used (AWS A 5.28), it's a 2% Mn 0.5% Mo alloy with approximately 0.10% carbon content.

Welding Tips & Techniques

If the steel is roughly thicker than 5mm, it is wise to preheat up to 250 degrees celsius to slow down the cooling rate and thus keep the heat affected zone free from low toughness martensite phase during cooling.

For welding, it is best to use high grade argon and to eliminate all sources of moisture.

In the UK, A31 would be similar to ER80S-D2 but may not be so clean, ER80S-D2 and A31 have good weld ability and welders enjoy using them. Also, the 0.5%Mo sweetens the arc.

Also see MIG A31 ER80S-D2 Welding Wire.

© 2024 AES Industrial Supplies Limited

Company Registration: 07988136 Registered Office: Olympic House, Collett, Southmead Park, Didcot, Oxfordshire, United Kingdom, OX11 7WB


We have placed cookies on your device to help make this website better.