360 - mini hypnodisc

[ian_humphrey]

Little spinners teeth at the last event were case hardened P20.. when they hit satanix they dug about 5mm into the mild steel then snaped there own titanium bar/disc... the p20 didnt even scuff.

I can see what your saying and I wouldn't expect the P20 to show any signs of damage against mild steel either. The reason being mild steel has a Brinell hardness of about 120 with sod all alloys but Hardox will have a minimum of 400 Brinell with lots of alloys and is designed to be wear and impact resistant so the results could be different.

I was only suggesting that hard edges could chip and therefore lose the nitrided layer and expose the softer material underneath.

I am actually quite intrigued to find out what the effects would be and how nitrided P20 would stand up.

My interest comes from the fact that I do heat treatment for a living, in fact I work here http://ht.bodycote.com/?OB=81&POB=276&ID=352


Ian

[Mouldy]

http://www.westyorkssteel.com/P20.html

Im just working from that site and the idea's kennys given me. Hardox 450 has a rockwell hardness of 45, nitride coated p20 should be around double that im told.. thats all ive been going off. apparently case hardened p20 should give a Rockwell of C55/59 if done right. Which should be enough.. but for abit more i thought the nitride would be a little better.

Ian, What would you suggest then? If you can sort somthing out for us that you think is going to be the best solution and post it on here ill get it sent to your company if you can get us a quote, or do it of the back of the lorry have you worked with P20 before? I think its used for a lot of press tools.

[cliveb]

Dont do it Ian, he might just try it out on Dinah.

[kodster]

Hmm...P20, you say. Sounds tough enough, though possibly brittle. How good is the strength-to-weight ratio against Hardox alloys

[perhaps I should open another thread for this... ]

Um...360 rules by the way. Nice pics and renderings too.

[Kenny]

it isn't brittle its a shock tool steel used in alot of press tools where tools are hit together with like 200 tonnes 24/7 365 days a year, for years and years

[Mouldy]

P20 compaired to Hardox...

Hardox is alot softer. p20 is a tool steel.. you use tool steel to machine hardox

I dont really see the point in compairing.. not many people would bother buying p20, its to expensive and it carnt be bought in thin sheet, and i dont want to many people buying it if it works :P garys already gone and done it lol.

Its also not easily machinable, I had to get Kenny to machine it as machining tool steel is part of his job, even Ed wallace wouldnt of been able to machine it due to needing real high quality tips to work with it.

As for price.. My disc has cost 430.. just for the rim, without hardening.

But if anyone's interested theres a round offcut for sale lol

I think THZ's nasty axe is nitride coated tool steel. I could be wrong? (John?) but that takes a hell of alot of shock.. and doesnt seem to break.

[typhoon_driver]

Even if the nitride coating comes away in small chunks it doesn't matter. The P20 underneath will be more than enough to do suitable damage.

My hardox disc on hornet 2 took a hell of a hammering through the 6 events it was at and I ended up having to remove around 3 to 4mm of material off the original single tooth with grinding it down. I seriously doubt I'll have to do anywhere near the same with my P20 disc.

If you don't believe that P20 will do well in the arena I'll be only too happy to throw my next featherweight in with yours and we will see which comes out better. Best of luck shattering the 1inch thick disc

[RogueTwoRobots]

But if anyone's interested theres a round offcut for sale lol

Just cut two of these out and that'll be me partially sorted for the drum of Drumroll II:[attachment=0:3jyu8q5s]drum_disc_sketch.JPG[/attachment:3jyu8q5s]

[team_orr]

...drumroll 2 :shock: uhoh....

[ian_humphrey]

Just to throw a bit more information into the arena , P20 in it's as bought state is about 300 Brinell which is about 33 Rockwell C scale. Hardox is designated by its Brinell hardness so Hardox 450 is about 450 Brinell which equates to about 47 Rockwell C scale. When you nitride P20 it will give a surface hardness of around 650 Hardness Vickers which equates to about 56 Rockwell C scale whilst retaining the original core hardness, this is what makes so P20 suitable for nitriding.

Heres are a couple of more links for P20

http://www.schmolz-bickenbach.com/fi...PLAST_2311.pdf

http://www.carrs-tool.co.uk/products/P20Spec.htm

and one for hardness conversion

http://en.wikipedia.org/wiki/Hardness_comparison

I'm still looking forward to seeing it in action.

PM sent.