Welding 4130 1

[Guanton75]

I need to weld a seam in 1/4" thick 4130 which will be heat treated. It will be seeing very high impacts infrequently. Can you suggest a welding filler material to be used by a mig or arc welder? Suggestions on heat treatment schedule would also be helpful although I think I have this area covered.

Thank you,
Seth

 

[evelrod]

Re.--- Thread288-39801


Rod

 

[DickHovey]

For TIG or MIG you have 2 choices.
For UTS of 125ksi or less, use E70-S2 filler.
For UTS > 125ksi use 17-22AS filler.
Source is MDD/Boeing data from my time at Air Canada.

Dick Hovey, P.Eng./ing.
AEROTECH RMH Inc,
Montreal, Quebec

 

[Carburize]

It depends what you mean by "4130 will be heat treated". If this means that the whole welded assembly will be quenched and tempered then ESAB make covered electrodes which deposit weld metal matching the 4130 analysis which will respond to the quench and temper heat treatment in the same way as the base material.

 

[evelrod]

Gee, that's too complicated for me. I have welded lots of 1/4 " plate 4130 with either E70xx or E80xx stick a bunch of times . No problems. If you are going to 'heat treat' as in above post, stick to E80xx or better. If you are just going to 'normalize' the welded area to prevent cracking or checking then either will do.

Rod

 

[GRoberts]

A lot depends on your application and strength required. 4130 can be heat treated from medium to high strength, with tougness varying inversely with strength. The first thing you should do is find out what tensile strength (or temper) the base metal is. This will affect the amount of preheat that may be required for your application. Once you know that, general guidelines or experience can be followed to arrive at an adequate preheat temperature. Otherwise it may be trial and error. Or if you know the chemical analyis, Lincoln makes a preheat calculator that can provide good recomendations for preheat temperatures. Additionally, you need to know how strong or tough the joint needs to be. If it needs to be matching strength, you can find a matching tensile strenth electrode, assuming your PWHT is just a stress relief. If you are going to quench and temper the entire weldment, Carburize's post contains the proper information. If you are going to "normalize" the weldment as evelrod mentions, and you want matching properties, also use the 4130 electrode from ESAB. If you don't need matching properties, the 70xx or 80xx electrodes would be acceptable.

If the above information is not applicable to your situation, or you need more specifics, you need to post more specific information about the base metal and what properties the weld needs to have. The keys are knowing what you have to weld on and knowing what you need when you are done. (property wise)