wheels 543 Posted March 13, 2017 Share Posted March 13, 2017 isn't the stainless that is weakly magnetic also more likely to corrode? Mmmm, yeah......nah.....kind of. It's a little more complex than the magnetic property, although magnetic property can be a telling feature. Firstly, this is B!&&$# complex and I would be telling Trumps if I said I knew it all on this. We all know there are many grades of SST. Each has a reason to exist. Just because a SST is magnetic does not mean it is Inferior or poor Chinese quality or anything like that. The 300 series of SST's have Nickle added and the Carbon content is low. But this makes the SST Brittle to work and subject to micro cracking and work hardening. All metals are a crystaline structure and the crystals can be changed in shape and type with the addition of other metals and manipulated with heat. With the 300 series, the Crystal is formed in a particular way with the addition of Nickel. The Crystal is called Face centred (FCC) and this means there is an Atom at each corner of a box and an Atom in the centre of the box face. Non Nickle SST's are Box centered (BCC) which means the centre Atom is in the centre of the box, not the face. From what I understand, it is the Crystal shape that makes the 300 series not Magnetic. ( I could be wrong) and if you cold work the 300 series, you can in fact make it slightly magnetic, because cold working physically crushes the Crystal structure and changes it's shape. But heating (annealing) the SST to 1050DegC and then quenching causes the Crystal structure to change back. 316 has Molybdenum added and this makes the 316 more resistance to Chlorides, with Salt being Sodium Chloride of course. But 316 is more brittle and much harder to machine than 304. 304 is often used where the metal needs to be formed, like a Sink for instance. It is less subject to cracks when bent. In earlier days, 304 was the only SST available for Bolts and fastenings because the threads were cut. 316 was too hard to form threads by cutting. Today, thread are usually rolled on rather than cut and so 316 fastenings are just as readily available. Although somewhat more expensive. Quote Link to post Share on other sites
hb1849 12 Posted March 13, 2017 Share Posted March 13, 2017 Each has a reason to exist. Just because a SST is magnetic does not mean it is Inferior or poor Chinese quality or anything like that. Indeed -- plenty of "high end" stainless steels are magnetic. 17-4PH is a common example -- much stronger than 304/316, magnetic. Duplex grades are also magnetic. Quote Link to post Share on other sites
erice 732 Posted March 13, 2017 Share Posted March 13, 2017 flat tin marine bbq likely to be either of the 2 most common SSTs 304 or 316 - both containg nickel so non-magnetic and almost no carbon, chromium - makes SST not corrode (and defines stainless steel) nickel - makes SST less brittle by changing the base iron's crystalline structure (from ferrite to austenite).............also making it non-magnetic 304 stainless steel contains chromium (min. 18%), and nickel (min. 8%). It is an austenitic steel and is only slightly responsive to magnetic fields. 316 stainless steel is much the same but also has 3% molybdenum, so more corrosion resistant as well as harder, stronger at high temp. etc however kitchen stainless, 400 series, has no nickel, (meaning the ferrite is still there = magnetic) and higher carbon, making it harder, so holds an edge better for knives etc The '400' series stainless steels (about 18% chrome, but no nickel in them) that are often used in a kitchen are magnetic. https://www.thebalance.com/200-series-stainless-steel-2340101 interesting the nitrogen - manganese 200 series - but let's not go there...or to vanadium, martenitie etc https://en.wikipedia.org/wiki/SAE_steel_grades Quote Link to post Share on other sites
waikiore 400 Posted March 13, 2017 Share Posted March 13, 2017 Most likely it is 303 or 304 Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.