Welding SS 304 to SS 316

As I recall the rule of thumb is to go with the highest, closest rod/wire available. If I had 316L available, I'd use it.

The web is full of excellent resources, but you may find that there are lots of opinions about proper welding techniques and materials here. Depending on the use, mild steel rod/wire will join the two metals. I've done it.

I'd do some independent research.

Rule of thumb when welding dissimilar steels:

Use a filler material of the better grade of steel, i.e. for welding 304ss to 316 ss use 316 rod, when welding stainless steel to carbon or low carbon use rod of the stainless steel material.

If the strength of the weld is not a critical issue Ni rod is very forgiving.

Size of the rod is dependent on the thickness of the material that is being welded

Nickel is also very expensive. Also keep in mind your heat input as SS will warp and distort if not careful.

You should try to avoid warpage. If you weld for 10 or 15 seconds, and rest until the area is below 100 to 150C, you will minimize this.

Same technique works well, for anyone trying to weld without burning off the paint on the back of the work area on thick plate.

David

Agree with the answers, 316L would do fine. Also 304L. Also Nickel. But, as a last alternative, any 300 series with low carbon content would give you reasonable results. You are lucky, dealing with austenite ones. Keep carbon low and everything clean, and no problems may arise.

Hello everybody:

I very much appreciate your opportune comments. Thanks to all.

I was always taught to use either 321 filler or 311 or 309, the problems of welding 304 to 316 are stress corrosion cracking where carbides precipitate out in the HAZ zone, there is more carbon in the 304SS than the 316L which has a lowered carbon content. The problems are not apparent straight away but if it is a loaded structure or vacuum vessel (in our case) it will fail.