>>>or do some grades of stainless actually rust easier than others....
Some stainless can be very bad with rust, I've found 440 to rust like crazy. If you fart near it it rusts.
>>>I mean they both seemed to cut with the same degree of difficulty that I usually find with SS.....
don't think of it all as just SS. The propertied vary so widely. The scrapper around the corner gets all cranky when I bring in barells of "SS" thats magnetic, so I bring out the book and show him, no its not all non-magnetic, then I show him the certs for the material. Then he gets really cranky when the barrel is full of yellow chips, well its not blue, must be stainless, out with the certs.
Seriously though, the category of stainless is so widely varied when it comes to machining properties. A simple Stainless designation means almost nothing, magnetic means nothing, some of its fun, some of it sucks. Ever mess with 13-8, horrible sound, beautiful cut but it sounds like hell. 440C, eats tools, crappy finish and has a very unique smell, 440F same smell, same crappy finish, cuts like butter. 17-4 acts just like a heat treated alloy steel, but shinier(my personal favorite). 303, cuts real easy, tough to get a good finish. 304, gummy sticky nasty crap, responds well to aluminum type geometries, sometimes. get into the super alloys(inconel, waspaloy, hasteloy, a286, hp-9-4-30) they respond well to aluminum type tools also. Then you get into the ceramic tools and big fire balls, and it just gets more fun.
I would suggest getting your hands on as many catalogs as you can, from both metal suppliers and tool makers. The ones from the metal supplier will give you all kinds of info on available conditions, heat treat specs, properties of various materials and the tooling catalogs will flood your mind with how to go about cutting all those various materials. fun stuff.
what were the chips like?
My guess is that one is PG C1045
Looks much like stainless, but you get blue chips when machined with a carbide tool.
my suggestion for what its worth.
test both what is left if any with a magnet as machihing(cold working) can cause a slight amount of magnetism and it will pick up irorn for hss tools. If both prove to be non-magnetic you have your answer and both are likely what you ordered. If this is the case you can get muratic acid at harware store, degrease the part and disolve rust in probably 1/2 hour. If one bar is magnetic and one is not then send the other(mag one) back and ask them to replace. Most (90%) of 303 sold is regular annealed and unless you asked for the se or b grade you probaly wouln't get them. You might also check the color on the ends of the bar and see if they are the same. Again if different material is probaly also differnt.
Well I went and got some muriatic acid
(I wasn't aware of it's ease of availability), and I soaked the part in about a half-cup, in a plastic container.
The acid did it's work I'd say, (about ten miutes) then I thoroughly rinsed it in cold water and buffed it.....now I will put it in the ultrasonic and then autoclave it tomorrow....we'll see how it goes then (or maybe after the ultrasonic if all goes poorly).
My question now is what do I do with the acid?.....the guy at the hardware store said to put it in a five gallon bucket of water and I could then pour it in my backyard...the water and bucket part sounded fine....but the pouring out part....??
Any further input is appreciated (and needed at this point).
Fishfrnzy, the entire bar that the part was cut from is magnetic...and not just slightly either......something seems a tad off to me.
My refernce material states that type 303 in the annealed condition should be non magnetic. It is possible you have 303 condition "B" which is cold worked to increase stregth but since you aslo have the rusting problem and cond B is rare stuff I would say you did not get what you wanted. You could ask for certification which, if they accurately kept track of their stock would tell you.
As for the acid someone out there surely knows more but 5 gals water would be about 100/1 and should be ok to dispose of. Or if it makes you feel better dump a box of baking soda in bucket first.
As already hinted at...basic chemistry. Baking Soda neutralizes acids...Ok to dispose of outside then. Dilution is OK but neutralizing is better.
I thought of the baking soda, 'cause I use that to neutralize the flux when I solder, but the guy at the hardware store wasn't sure....and I didn't want to chance it having to rely on MY retention of high school chemestry facts ha ha.
I will add some baking soda and dispose with a sounder mind now....thanks all!
Oh, and by the way, that part rusted again sadly for me....so I'll call Nolan on Monday and see where I stand.
Muriatic acid is just plain old hydrochloric acid. Diluted with that much water it is weaker than what is in your stomach, same acid. It's fine to pour out on the ground, neutralized or not. Pour it any place you wouldn't mind barfing.
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Just dilute it, no different than dumping some ketchup on the ground. We do a bit of passivating at work, and the eco-friendly way to dispose of it is to dilute it (nitric). No big deal, by the time you run the garden hose over it, it can do no more damage than vinegar going down the kitchen sink.
The secret handshake for ordering 303 stainless: