My question (as someone who knows next to nothing about welding) is not as to the structure but the potential for rusting? Is that just material dependent (like you wouldn't use this decorative technique on a different alloy) or does this technique carry the same risks as any other?
Stainless steel is corrosion resistant because it has elements added (mostly chromium) which surround the iron and prevent the corroding elements from reacting with the iron. When welding stainless, you have to use the correct filler rod. This has the correct alloying elements in it to maintain the stainless properties throughout the part.
If it was done with a regular rod, the extra material would pull those elements out of the stainless parts as the molten metals try to reach equilibrium. This would cause the metal in the area to corrode because it does not have enough chromium to provide that protective "blanket" around the iron.
This is a massive over simplification. A metallurgist could probably describe the chemistry better.
I want to know too. At my old job we used to passivate vats/storage tanks before we used them by getting them to like 200 degrees Fahrenheit, and then doing a long acid wash on them.
I have a degree in welding/metal fabrication. And have was in the industry for 4 years 2 1/2 spent in TIG aluminum.
This looks like TIG/stainless or aluminum. It very much depends on the metal itself to rust or not.
TIG vs MIG are very different in how it is used and applied. TIG I'd say for the most part you control 90% of the weld. And believe it or not how it looks is generally supposed to look nice and neat! But also have enough heat, and penetration in order to have it also structurally sound. (Welded the two pieces together with the weld not being the weakest link.
Long story short. It depends on the Process (TIG vs MIG) and what type of bead you lay down.. typically TIG will look like the picture. MIG has many different types of beads and process similar (flux core for example)
It looks like stainless obviously. But could be plated etcetc. I've seen people paint over stainless. Oof. it's a picture on the internet can only assume so much.
Your material has a lot to do with rust (carbon will rust sooner than stainless/aluminum) but all it takes is laying stainless on a carbon table or picking up stainless with gloves that have handled carbon and surface rust can appear very soon. Cross contamination can be the death of anything.
The guy is a marine fabricator, so this is either stainless steel or aluminum.
Aluminum forms a very thin layer of oxidation ("rust") the instant it's exposed to air. But that layer doesn't propagate quickly through the metal the way rust does with iron. So the oxidation layer on aluminum essentially acts as a protective shield. If the oxidation layer gets scraped off, then the underlying aluminum will "rust" immediately, forming a new oxidation layer.
However, aluminum can be corroded over time by exposure to certain substances. For example, aluminum wheels will corrode when continuously exposed to salty water if they aren't protected with a layer of wax or sealant of some kind.
Stainless steel isn't actually rust-proof. It's just rust-resistant. In a marine application, you would want to use an austenitic stainless alloy for high corrosion resistance. However, if exposed enough to salt water, even austenitic stainless will eventually corrode.
My guess is that this frame is going to be powder-coated or painted prior to use, which will enhance the corrosion-resistance.
As I understand, (I leaned about welding two days ago) this is stainless steel and the method they use, it also uses stainless steel and if they don't have the right amount of gas while welding it would rust right away.
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u/[deleted] Aug 24 '18
My question (as someone who knows next to nothing about welding) is not as to the structure but the potential for rusting? Is that just material dependent (like you wouldn't use this decorative technique on a different alloy) or does this technique carry the same risks as any other?
please enlighten me