Welding 4140

Date 08-15-2007 23:17

What is the proper filler to use when mig welding a 4140 weldment. We need to weld end plates and a axle in a 1" wall 4140 steel tube for a 15" long roll. I have been told to use an e80s material because e70s would crack, and I have been told e70s would be fine by another reliable source what is the correct answer or does it matter? Plan on 035 wire using 75/25 argon co2 mix
thanks
John

By Joseph P. Kane (****)

Date 08-16-2007 01:58

E120-xx. High preheat. PWHT required.

By JohnKish (*)

Date 08-17-2007 01:26

why E120?

By Lawrence (*****)

Date 08-16-2007 03:10

John,

I noticed you selected 75/25 Argon/CO2...

For inch thick material you might want to consider a shield gas that can prodouce spray transfer.

By JohnKish (*)

Date 08-17-2007 01:26

The roll were presented to me with a 3/8" wide 3/8" deep u groove what shielding gas would you suggest and why the differing opinions on filler metal?

By DaveBoyer (*****)

Date 08-17-2007 04:33

To make an informed suggestion on the filler material You would have to state how hard or strong the actual weld has to be. The cracking would be caused by improper pre and post weld heat treatments. The design and use of this roll dictate what the proper welding procedure will be.