Stainless steel used in Chinese made grills

Chinese "anything" is a crap-shoot. Drilling stainless requires a sharp bit, a slow cutting speed,and lots of pressure. You want the bit to bite ALL the time. If it slides and heats, you are finished - generally speaking. As for welding, using the same alloy as the project works best - but any stainless rod will likely be "good enough" since it is not something that needs to look good close up. Best to stay with either magnetic or non-magnetic, whichever the project is. I'm not a professional welder - nor do I play one on TV - but I have done some welding - including stainless - and a good friend of mine is a real tig artist with SS.

Also, the thermal conductivity of SS is higher than plain steel. It welds beautifully and you will be tempted to weld without filler. As Ed Huntress mentioned, this is a bad idea because element depletion will result in rust surrounding the HAZ.

--Winston

Sorry, you got it the wrong way round; the thermal conductivity of SS is less (about a quarter in some cases) than plain steel, *that* is why it welds nicely.

Uh, lower. By quite a bit.

When you weld stainless you want to use a rod that has higher nickel and chrome content then the part you are welding and that has lower amounts of carbon. Since you do not know exactly what alloy of stainless you have in the grill, which rod to use for the lowest cost is unknown. But the more chrome and nickel the better, but more expensive.

Is the grill magnetic? If it is fairly strongly magnetic , that would indicate a 400 series stainless. Not strongly magnetic would be 300 series.

I would expert 308L would be fine as I doubt the grill is a high chrome alloy. 309, 310, or 312 would probably be over kill.

Dan

Yes. Both you and Ed are right. Senior Moment.

I *meant* to say 'lower'.

--Winston

(...)

Exactly right. My error.

I looked up the thermal conductivity after I welded my chef's knife because the SS was acting as if it was dissipating heat even worse than regular steel. Indeed it's thermal conductivity was *lower*.

--Winston

The safest choice for unknown ferrous or nickel based alloys is Inconel 625. Inconel 82 is also quite forgiving. If the grill is strongly magnetic, most any Inconel alloy would probably work somewhat better than a 3xx (austenitic) rod. If the metal is non-magnetic, or only weakly so, it's probably austenitic and any 3xx rod will work.

I am very happy to hear it, because I have a nice assortment of inconel rods.

I hate drilling ss, so if the material is thin enough & the number of holes large enough, I use the plasma cutter. Make a template by drilling a larger, right-size, hole in a piece of MDF or whatever's handy. Bob's yur uncle.

Bob

I HOPE it was just a brain fart - thermal conductivity of stainless is SIGNIFICANTLY LOWER than plain steel. And autogeneous" welding of stainless is SIP in MANY situations (welding with no filler). Passivating the weld is sometimes required to avoid rusting.

Autogeneous welding of stainless is risky unless you know the steel you're dealing with and you're using the right technique. With duplex stainless, you get a variety of precipitates if you don't swamp them with extra chromium and nickel. In austenitic stainless, you can get nitrides.

Some classes of stainless welding are usually done without filler, but for the hobbyist, especially with unknown grades of stainless, extra nickel, particularly, can solve some potential problems -- including diffusion of nickel and/or chromium that leads to corrosion.

snipped-for-privacy@snyder.on.ca wrote: (...)

Correct! I cop to the boo-boo. 'Significantly lower', yes. I forfeit two RCM 'attaboys'. :)

I found that to be the case after I autogenously welded my chef's knife back together. (Note to self. Use something else for chopping.)

It rusted on both sides of the HAZ for months. With continuous cleaning using a non-metal scrubber, it isn't rusting and it is nice and shiny again. It is my favorite knife once more.

My thanks to Ed for explaining the metallurgy in simple terms.

--Winston

The best grilles are made from Inconel. You weld them together with 901 Incoloy rod.

It's a little pricey but mine is going on 20 without much care or difficulty.

My neighbors don't have superalloy barbecue grills. You must live in a cool neighborhood. d8-)

Just remember to use a stainless steel brush if you do any wire brushing or you will contaminate it and it will rust.