Thread: stainless steel ?

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Been using some stainless to build a little wrecker type jen'pole for one of my toys. "think of Mater from CARS ,and picture his in polished SS "
While buying some odds and ends an older fella commenced to tell me about how I should not "grind" on any of the stainless I'm using for risk of detritions /oxidation .... "I thought it was stainless! "
I asked but he couldn’t elaborate … so I let it go … but now I’ve been wondering .

One of you metallUrgist care to enlighten me on this ?
Is he a sandwich short of a picnic or am I uninformed ?
I'm using stainless so it would be here for all time
Once it is all polished, Just climb up, buff a little ,wipe some polish and keep going.
from what I could gather ,cutting is fine but grinding big spots is a no, no, as in shaping w/a grinder? .

From the heat? I weld it and have never had problems...

And yes the wrecker will be functional just won't be used a lot.
just wondering if there is something i should know about SS.


T L

Not a metalurgist, but I do know stainless will rust. We had this argument from customers in the boat business for years now........they buy a boat and accuse the mfr of using cheap stainless because it rusted. We had to explain it is stain-LESS, which means it will still rust, only more slowly. They somehow thought they never ever had to do any maintenance on it to keep it shiny.

Don


Stainless steel
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The 630 foot (192 m) high, stainless-clad (type 304) Gateway Arch defines St. Louis, Missouri's skyline.
The 630 foot (192 m) high, stainless-clad (type 304) Gateway Arch defines St. Louis, Missouri's skyline.

In metallurgy, stainless steel is defined as an iron-carbon alloy with a minimum of 10.5% chromium content.[1] The name originates from the fact that stainless steel does not stain, corrode or rust as easily as ordinary steel (it "stains less", but is not actually stain proof). This material is also called corrosion resistant steel when it is not detailed exactly to its alloy type and grade, particularly in the aviation industry. As such, there are now different and easily accessible grades and surface finishes of stainless steel, to suit the environment to which the material will be subjected in its lifetime. Common uses of stainless steel are everyday cutlery and watch straps.

Stainless steels have higher resistance to oxidation (rust) and corrosion in many natural and man made environments; however, it is important to select the correct type and grade of stainless steel for the particular application.

High oxidation resistance in air at ambient temperature is normally achieved with additions of a minimum of 13% (by weight) chromium, and up to 26% is used for harsh environments.[2] The chromium forms a passivation layer of chromium(III) oxide (Cr2O3) when exposed to oxygen. The layer is too thin to be visible, which means that the metal remains lustrous. It is, however, impervious to water and air, protecting the metal beneath. Also, this layer quickly reforms when the surface is scratched. This phenomenon is called passivation and is seen in other metals, such as aluminium and titanium. When stainless steel parts such as nuts and bolts are forced together, the oxide layer can be scraped off causing the parts to weld together. When disassembled, the welded material may be torn and pitted, an effect that is known as galling.

Nickel also contributes to passivation, as do other less commonly used ingredients such as molybdenum and vanadium.

What Don said is correct. What stainless are you using? The 300 series (austenitic) are much more resistant to rust than the 400 series materials (ferritic).

Some times there is iron in the grinding wheel or media that gets trapped in the surface and causes 'rust'. When ground the fresh material is exposed to oxygen and will re-passivate naturally. However if there was foreign matter such as iron on the surface it can become trapped and will rust. Keep it clean and you should be OK. Make sure there is no iron oxide in any buffing compound you may be using etc.

Kitz

what do you say when you shouldn`t have made a silly post .. i wish the delete function were turned on

I feel cheated ! roshamBO.gif


Wonder how much " Will not stain " would cost ....



I'm learning so its not a "silly post" to me ... hoss ... now showing I was a butt on a cool forum
would seem silly to me.

(austenitic) or (ferritic) ? cheapest is what I got.



T L

my remark was silly but i editted it away .. not your question ..there are no silly questions .. just silly replies sometimes .. all is well .. we use a lot of stainless steel here where i work and it is stored outside .. the only time iv`e ever seen any rust is if it came in contact with lesser metals and the rust seemed to bleed onto the stainless

Remember though, Everything Rots. Some stuff just rots faster than others.

That's what forms the basis of my positive mental attitude from day to day.

Kitz

Stainless absolutely will rust. If you have ever owned a boat, like I cited above, you know that keeping it clean is an ongoing proposition. Cleats, chocks, screws, and other items made of stainless will rust for sure. Certainly not as bad as regular steel, but it can range from surface rust to pitting.

I've probably had 30 boats over the years and haven't owned one yet where the stainless was "stainproof." Obviously stainless fittings on a car are going to be less prone to this problem, but not totally immune.

Don

Expensive stainless wont rust ,cheap stainless will....

All is good Hoss

I guess I was getting schooled on compounds and grinder disks .


I really didn't think I'd have to mess w/it much after I polished it ,other than wipe it off every so often .
thanks for the replies

Now anywhere I touched with the other grinding pads I'll be worried about.
Glad I didn't start polishing it yet ...
I have got SS bolts and washers for the parts I’m not welding

Bigtruckdriver - it wasn't cheap but it was... cheaper

I guess I'll have to get the buffer after my cleats ! I thought they were that way so the fish didn't jump in the boat -

Thanks guys I was just having a brain fart ... stain...L..E..S..S not .. stain proof . got it .

T L

304 stainless will rust. I have seen that happen. 316 stainless is not SUPPOSED to rust. I have one customer who builds stainless steel pallet trucks for the meat packing industry--(a lot of slop, guts, anad yuchhh) Thy will only allow their machinery and lift trucks to be made from 316 stainless. I have to put a material grade spec. on all the machinery I design for him.

the 300 stuff is better then the 400 ss if a magnetic will stick to it .then it will turn dark red / brown

sorry guys stainless steel does not rust, if you buy stainless steel that rusts you bought a very poor quality stainless if it rusts, that is why they use it in the food industry, that is the only metal that is allowed to be used in the food industry because it does not rust, i have welded thousands of stainless steel parts for food service and have never seen 1 piece of stainless rust

also that is correct pat, if a magnet sticks to it it is poor quality, 304 ss and 316ss are common grades,

on the grinding disks just use a new one that has never been used on regular steel, if you do you will get small rust spots on the stainless from steel embedded in the stainless