Welding 1040 to 1020

Date 05-05-2005 18:38

Hello! I am new to the group, but have a question that I just can't seem to find an answer to. We have a machine gun mount that needs to be welded, but the vendor making some of the parts is supposed to use 1040. They have called saying they can not use the 1040 because it will become brittle during welding. Is this true?
Now, the other vendors are making parts out of 1020. So can 1040 be welded to 1020 with relative ease?
So of course, the question becomes if the 1040 does become brittle is there anyway (besides going with new material) to weld without it becoming brittle?

Thank you for your help. I weld but have never come across an issue like this one.

Michelle

By DGXL

Date 05-05-2005 20:25

1040 medium carbon steels are commonly joined, particularly with low carbon steels. Proper preheat, monitor of interpass min./max. temperatures and proper filler metal selection should make this task relatively simple. Was there any PWHT specified?

I think the fabricator does not know what he/she is doing based upon their statement.

That's all I'm typing you until you get a Ford...

By michelle (*)

Date 05-05-2005 20:43

Well see thats the thing- the vendor I think just wants to get out of buying the material. I found out that it can be welded but not very easily. The weld specified is just one pass about 1/4" thick. The weld is pretty small, but stitched along all of it. So I heard that pre-heating was necessary but we also had to post heat.
Ahhhh I don't want a ford!! :)

By G.S.Crisi (****)

Date 05-05-2005 23:01

I don't think the vendor doesn't know what he's talking about. I think that he just wanted to warn Michelle that welding SAE 1040 (a medium carbon steel) isn't that easy as welding SAE 1020 (a low carbon one) and some precautions should be taken.
Giovanni S. Crisi
Sao Paulo - Brazil

By michelle (*)

Date 05-06-2005 17:34

So does that mean that the post and pre heating are required to weld the 1040 to the 1020? Also, the plate is only a 1/4" thick.

By G.S.Crisi (****)

Date 05-09-2005 14:33

The preheating is required. Regarding post heating, I'd say that it's not required, taking into account that the plate is only 1/4 inch thick.
What I would do is to wrap the welded area with insulating material after the weld is complete, so it cools down slowly.
Giovanni S. Crisi