Welding stainless to mild steel.

  1. Ray-S Member

    Messages:
    20
    Location:
    Carlisle. United Kingdom
    Sorry if this has been covered before. If you need to weld stainless steel to mild steel do you use stainless wire and appropriate gas? Also are the settings similar to what you would use for welding mild to mild. Thanks.
     
  2. MichaelV

    MichaelV Forum Supporter

    Messages:
    178
    Location:
    Co. Antrim
    Ray, 309MoL is often the appropriate grade of consumable in this situation. If you search on that phrase you’ll find various manufacturers’ datasheets with recommendations on gas, parameters and the more subtle aspects affecting dilution into the base material. The old Avesta handbook (online in various places) has great guidance.

    Michael
     
    Dcal likes this.
  3. waddycall

    waddycall Member

    Messages:
    1,111
    United Kingdom
    Depends what you’re doing. Over 10 years ago I welded two mild steel 1” bsp sockets to a a 6” test flue using mild steel wire and no gas as it ran out at the end of the job. They’re still holding out.
    N.b. There is no load on them!
     
  4. Ray-S Member

    Messages:
    20
    Location:
    Carlisle. United Kingdom
    I only have mild steel wire with appropriate gas at home but we have stainless at work (BMW garage) although it has never been used. Think it was BMW minimum standards made us get it for welding flexi repairs into particle filters but we sub them out for some reason. Need to have a look tomorrow and see what we have.
    What am i doing? I made a crude metal brake some time ago, not very good and needs modifying. If I am going to do that I might as well make a proper job. I need some steel bar for the hinges but as I don't have access to a lathe there is no way I can drill through them and have everything square so need to buy some steel spacers but I can only find stainless steel ones on ebay. eg. https://www.ebay.co.uk/itm/Stainles...rentrq:a5686c2b16c0a9e1dacf3f2dffff84fb|iid:1
     
  5. LewisT Member

    Messages:
    124
    central scotland
    Definitely doable my uncle appeared at my house the other weak with some steel gates that needed new hinges which were some cheap b&q stainless they welded fine with mild steel wire and 95 argon 5 co2.
     
  6. barking mat

    barking mat Member

    Messages:
    2,652
    Location:
    Brittany
    Yes, use stainless.
     
  7. Munkul Member

    Messages:
    1,936
    Cumbria, UK
    as said above, the proper way is 309L, BUT...

    I've had good success with non critical things being held together by using regular mild steel ER70 filler, both MIG and TIG, for mild-to-stainless.

    Using stainless 316L rod on mild steel does not work very well, though. Not in my experience. Creates a very brittle joint.
     
  8. Hood

    Hood If it walks like a duck....

    Messages:
    11,165
    Location:
    Carnoustie, Scotland
    I found exactly the opposite, steel rod to join steel to stainless and it is a brittle and easily cracked joint, also corrosion seems to be accelerated at the weld. Using 316 I find the joint is much stronger and resists corrosion much better. Using 309 however is the ideal choice and the way to go on anything that will be taking any knocks or exposed to the elements, especially marine environments. Just my opinion and observations from many years of working on fishing boats, others experience may differ :)
     
  9. Dcal

    Dcal Forum Supporter

    Messages:
    1,933
    Location:
    Antrim Northern Ireland
    Michael, great information in that handbook, thanks for posting.
     
    MichaelV likes this.
  10. MichaelV

    MichaelV Forum Supporter

    Messages:
    178
    Location:
    Co. Antrim
    It’s a wee trove, right enough!
    M
     
  11. MichaelV

    MichaelV Forum Supporter

    Messages:
    178
    Location:
    Co. Antrim
    Ray- as it happens the guys at Weld.com are doing a YouTube video tonight on the very topic of welding stainless to carbon... using 309 consumables. Worth a wee gleek, I’d say.
     
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