Replies to post #29059 on The Rising Influence of Rising Affluence

[spongepaul]

I appreciate your knowledge on this. Thanks for sharing it. I learn something new on these boards every time I log in.

[n4807g]

Personally if I had one of these Cybertrucks I would be pretty angry

But...they're, "bullet proof"....LOL up to a point I suppose.

[jbog]

Mufaso,

You did a great job on your explanation. For the last 52 years I built a company that solely builds systems for the Food and Pharma Industries Worldwide. We use somewhere in the area of 260,000 lbs. of ,Stainless per month building Vessels, Tanks or Systems.

What I have understood so far is that Tesla is using 301 SS which is close to the lowest grade available (we wouldn't allow that in our facility)which is cold rolled. To understand, Cold Roll is actually a Hot Rolled product that has been formed xxx. thousands thicker than specs, them allowed to reach room temperature a finally is squeezed to it's final dimensions. To Compare DeLorean used 304L and Autocar Trucks used 302. The final rolling will actually create a denser material.

Why Tesla is doing that is beyond me. Comparing today's auto's the standard material would be 1 mm thick, 1.5lbs sf while Tesla's Stainless is 1 mm thick, 4.5 lbs sf. This vehicle is a rock. Secondly, because of the cold rolling this metal doesn't want to be formed, that's why the truck looks so different, only straight lines by bending, not forming. No contours or flairs, only straight lines. 301 SS is austenitic as made but when bent it'll get much closer to Martensitic because of the micro structure change. I anyone ever gets a chance a magnet will not stick to the straight panels but will adhere to the bend lines.

Now getting to rust. Every metal will oxidize in the atmosphere. With Steel we would observe 'rust' if it weren't painted etc, Stainless Steel also creates a invisible 'passive' coating which protects itself. The problem comes that when the passive coating is scratched off, it any free iron is in the atmosphere the spot will rust, no matter which Stainless is picked, After any work, production etc of Stainless it needs to be passivated in a Nitric Acid solution which dissolves the existing passive layer along with any free iron near the surface. This Solution is then rinsed off with distilled water and the item is in a protected area for 18 hours while a new film is created.

As a warning, if you want to clean your stove top, if use get steel wool or a steel wire brush near it your toast. You can use a Stainless brush or wool all you want. Same thing with sandpaper, no carbon elements.
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