Welding Stainless Steel to Soft Steel

Thank you Lyn I'm going for

In my experience using mild steel wire is the best way to go. We do this all the time in our production runs where stainless is welded to mild steel. You are absolutely correct about the steady hand but also make sure you have your machine settings low enough for the gauge of the material.

I take it you are using a MIG welder???, your filler should be 309 SS, this is the most important, otherwise it will crack.

If you want more details or the reasons why, let me know I'm on my iPad now and is more difficult.... Otherwise google 'stainless to carbon pipe welding' you should get hits., there's plenty of solid information out there

Thank you

Also Search here on CR4. I'm sure we covered this within the past year or so. I know I list details. There's actual a lot of stuff, here is one thread.

http://cr4.globalspec.com/thread/60118/Dissimilar-Welding-of-Austenitic-Stainless-Steel-to-Carbon-Steel

Agree, best wire is .030 309 fluxcore. Weld deposit should remain rust free.

Last summer, for a cooling tower/water project I used 18" sch. 10 carbon steel pipe, and used sch. 10 304 SS fittings. The union contractor took it upon their self and used 6010 filler, even though I had 309 filler listed in my scope and project plan.....

After using the excuse they do it all the time without a problem, he even gave me the name of a instructor that test welds for ASME weld tests, of which I knew, I called and talked to him in a conference call.... the instructor confirmed, that 309 SS filler is what you use, (there are other fillers, but not readily available) and he would never recommend 6010.

The contractor spent 2 weeks grinding out the welds and re-welding all the joints.

Ps, this contractor could not give me one reference of a job where they used 6010 filler. :/

The OP doesn't have a stick welder.

HE HAS A WIRE WELDER.

You are confusing the issue and the OP!

I realize that as from my first post. I used 6010 as an practical example lyn.

Look, regardless of what you say, neither gas nor stainless steel wire is required for satisfactory welding of these dissimilar STEELS.

I would not have given the advice I did if I did not have historical proof that it can be done, and will not rust any more than the mild steel will under the SAME conditions.

And, it will not crack.

Lyn, I'm sure you did. I rely on people whose job it is for this. They may not have 100% failure! but it is in the low 90% and it's higher if there is vibration.

just consider yourself if not lucky, fortunate.

Agree, not a big deal.

I'm assuming our original poster is welding stainless dress tips to the CR steel exhaust pipes. This is far removed from the circumstance P911 is talking about.

What are dress tips?

<Damn! I still can't place an image!>

https://www.google.com/search?q=dress+tip+exhaust&rlz=1T4PRFB_enUS509US528&source=lnms&tbm=isch&sa=X&ei=qDazU_vYD9GYyAS3zoKgDg&ved=0CAkQ_AUoAg&biw=1920&bih=978

Thanks,.....

You'd think lyn door would sell that stuff.

WOW I didn't mean to start such a ruckus but I appreciate all the advice thanks...

Ha, we have a few industrial members here such as KrisDel, .... And LynDoor industries on here, I think LynDoor even have a website....... It may not work, but it's a website... you'll understand the ruckus....

By the way, welcome to CR4

Oh, don't worry. We "discuss" things vigorously often.

It's up to you to determine if any of us know what we are talking about. (I always do).

As I have replied several times on CR4, when welding carbon steel to stainless steel always use the filler of the better steel, i.e. use the stainless filler in your case. It can be done if you are careful not to burn through the thinner material. It is done every day to make such things as sample heat exchangers, chemicals going through the inner tube and cooling water through the outer carbon steel jacket. Also done to construct less expensive small reactors.

Always use the filler of the better steel when welding dissimilar materials.

Good Luck, Old Salt

Remember the weld has to be gas tight. Carbon monoxide, remember. Brazing is a possible route. Use Mapp gas and a brazing rod with flux.

I Agree.

When I was about 20-21 I brazed an exhaust (Cracked). It was on a Snowmobile, with higher vibration. It didn't quite last long enough till the new one came in.

Now that I'm on my laptop.

I had created an SOP to basically put plant operations experience out of peoples head and on paper. Here is a section when we are dealing with this process.

********

Welding Stainless Steel to Mild Steel

The usual choice for the filler when welding stainless to mild is 309L. 309 is over alloyed stainless steel (19/10) so when diluted by the mild steel gives a deposit approximately like 308L / 304L.

There are other fillers that give a crack free weld, 312, 308MoL, 307 and 310 will all work but these are less widely available than 309L.

Now that I'm on my laptop.

I had created an SOP to basically put plant operations experience out of peoples head and on paper. Here is a section when we are dealing with this process.

Welding Stainless Steel to Mild Steel

The usual choice for the filler when welding stainless to mild is 309L. 309 is over alloyed stainless steel (19/10) so when diluted by the mild steel gives a deposit approximately like 308L / 304L.

There are other fillers that give a crack free weld, 312, 308MoL, 307 and 310 will all work but these are less widely available than 309L.

* depends on environment - if Sulphurous it must be 410

** preheat of 150°C required

References

http://www.mig-welding.co.uk/stainless.htm

Other References

http://www.lincolnelectric.com/en-us/support/welding-how-to/Pages/filler-metal-detail.aspx

* depends on environment - if Sulphurous it must be 410

** preheat of 150°C required

References

http://www.mig-welding.co.uk/stainless.htm

Other References

http://www.lincolnelectric.com/en-us/support/welding-how-to/Pages/filler-metal-detail.aspx

Still confusing the issue!

The guy's not welding to any specification and there are no quality assurance inspections required.

He wants to use his flux core wire welder to weld two pieces of tailpipe together.

Try not to bore us with your purported knowledge when it isn't appropriate or needed.

Thanks Lyn, You guy's are really taken this subject to seriously, I just wanted to weld two tail pipes together....Want to thank all of you for youe info, Have a good 4th

It does get entertaining, but at times you need a thick skin,...

and right back at you.

We take everything too far.

Stick around, you'll be amused and learn something to boot.

Your right ... It is entertaining...

feeling better lyn?

if not, I hope you feel better soon.

or use this

#22

I was a union sheet metal worker for 16 yrs. certified in 6 types of welding, but was never trained on how to weld stainless to mild steel nor mild steel (black iron) to cast. For what it's worth: I have a 220 buzz box at home that I always use stainless steel rod with. Usually mild steel to mild steel but have welded stainless to mild steel. Keep in mind that stainless welding is higher temperature than mild steel. I believe that this is the reason most people here are recommending stainless wire/rod. A weld with mild steel may hold, but I recommend making sure it's a very hot weld all the way around. in other words, don't cool it off after tacking and make your final pass quickly after the tacks. The one time I welded a schedule 40 mild steel pipe to a cast iron exhaust manifold, the "old timers" told me to heat the joint red hot with a torch before welding with mild steel rod then weave the bead well (3/8") into the cast side and well into the mild steel side. The weld looked terrible but held up with no cracking before or after the exhaust was hooked up and used. Note: we let that thing cool slowly.

It does depends on what is the end use. If the use is not stated one sides with safety and use stainless.

Welding cast, yes you would have to pre-heat it. As for welding cast...... I myself leave that up to the people who earn a living welding like yourself.