Nitrogen alloyed Hadfield steel
Nitrogen alloyed Hadfield steel
(OP)
Hi, I am working on increasing the lifetime of abrasion resistant parts manufactured with Hadfield steel ( austenitic manganese steel ). I've read some articles about nitrogen gas purging into the melt while alloying with Ti or Nb which produces hard carbides and nitrides inside the austenitic grains thus increasing abrasion resistance. But i haven't heard of any foundry applying this technique, does anyone have information if any foundry uses this technique? And any other recommendations about improving abrasion resistance of manganese steels are appreciated :)





RE: Nitrogen alloyed Hadfield steel
Have you worked with different pre-hardening methods? Some of the explosive surface hardening methods are impressive.
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Plymouth Tube
RE: Nitrogen alloyed Hadfield steel
Some had suggested a bizarre addition of 2%Mg !!
RE: Nitrogen alloyed Hadfield steel
Nick
RE: Nitrogen alloyed Hadfield steel
EdStainless- I haven't worked with pre hardening methods like explosive hardening. But i've had some lab trials like heating the austenitized steel to 650C, hold for 8 hours, furnace cool and get some pearlite within the grains and some in the boundaries. Then heat it up to 800C, hold for 3 hours, furnace cool and get those pearlites little bit spherodized. I've some doubts about its toughness compared to austenitized steel so I didn't apply it to my customers parts.
arunmrao- I've read the following article, its like they had good results in laboratory. But its a mystery in shop practice.
http://files.engineering.com/getfile.aspx?folder=d...
RE: Nitrogen alloyed Hadfield steel
What parts are you studying for improved wear life?
RE: Nitrogen alloyed Hadfield steel
I have looked (unsuccessfully) for an old reference that was talking about 20% Mn grades.
They had added Ni (maybe 2-4%) and N (a lot, like 0.5%) and Mo(I think, or maybe Cr).
I don't recall C levels. You would need to look at the phase balance and estimate how much of the C will be in carbides.
Given that the Mn, Ni, N, and C are all austenite stabilizers I am not sure where you end up.
I do recall that pre-hardening (explosive or hammer forge) significantly reduced overall wear of parts.
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Plymouth Tube
RE: Nitrogen alloyed Hadfield steel
Ed, 20% Mn grade has a nominal C content of 0.8-1.0, though Ni may be present, Cr is 1.5-2.5 and Mo about 0.5.
Each manufacturer claims that his recipe is the best and the debate remains inconclusive.
RE: Nitrogen alloyed Hadfield steel
Abrasion resistance is improved by the use of second-phase carbides of V, Nb, etc., but always at the expense of Hadfield's classic properties.
"If you don't have time to do the job right the first time, when are you going to find time to repair it?"
RE: Nitrogen alloyed Hadfield steel
"If you don't have time to do the job right the first time, when are you going to find time to repair it?"
RE: Nitrogen alloyed Hadfield steel
Look at the Nitronic stainless grades with about half this Mn and they have 0.40% N.
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Plymouth Tube
RE: Nitrogen alloyed Hadfield steel
I am only aware of ASTM standards for Hadfield steel for castings - ASTM A128.
RE: Nitrogen alloyed Hadfield steel
RE: Nitrogen alloyed Hadfield steel
I face no issues with cones and mantle castings, but some variance in jaw plate castings. A 18% Mn steel has yielded no improvement in a few cases.
What is the grain refiner that you are using?
RE: Nitrogen alloyed Hadfield steel
my melting practice is using 50% scrap, deoxidize with 0,1% Al then Argon purging for 1 to 2 minutes.
RE: Nitrogen alloyed Hadfield steel
RE: Nitrogen alloyed Hadfield steel