4330v treatment for wear and corrosion
4330v treatment for wear and corrosion
(OP)
We need a tough high yeild material approx 10" dia for some tooling. 17/4 ph was used previously but has had some failures.
4330V has been proposed but we think we might need to treat it post machining to increase wear/corrosion resitance. EG Gas Nitriding and steam tempering (oxidising)
What concerns me is that these treatments are carried out at temps are in the range of the tempering temperature.
EG Tata have offered us
ASTM E4330V 260mm dia
Normalise at 910c for 6 hrs air cool
Harden at 880c for 6 hrs Water quench
Temper at 590c for 12 hrs Air cool
Stress Relieve at 520 for 11 hrs Air cool
Giving 1100MPA Ys (162KSI)
-50 Charpy of 45
The Gas nitriding is at 460-560 for long times.
Steam tempering is 450-500 Not sure about the times yet.
Concern....
4330V has been proposed but we think we might need to treat it post machining to increase wear/corrosion resitance. EG Gas Nitriding and steam tempering (oxidising)
What concerns me is that these treatments are carried out at temps are in the range of the tempering temperature.
EG Tata have offered us
ASTM E4330V 260mm dia
Normalise at 910c for 6 hrs air cool
Harden at 880c for 6 hrs Water quench
Temper at 590c for 12 hrs Air cool
Stress Relieve at 520 for 11 hrs Air cool
Giving 1100MPA Ys (162KSI)
-50 Charpy of 45
The Gas nitriding is at 460-560 for long times.
Steam tempering is 450-500 Not sure about the times yet.
Concern....





RE: 4330v treatment for wear and corrosion
You are correct that you can have some tempering occur during nitriding. The standard procedure is for your temper/stress relief to be at or above the nitriding temperature.
RE: 4330v treatment for wear and corrosion
RE: 4330v treatment for wear and corrosion
RE: 4330v treatment for wear and corrosion
What HT of 17-4 were you using and what were the failures? I would look at 13-8PH before you give up on PH SS.
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P.E. Metallurgy, Plymouth Tube
RE: 4330v treatment for wear and corrosion
RE: 4330v treatment for wear and corrosion
We currently want approx 100MPa yield with as high as possible charpy at lower temps. The 17/4 does not give as good charpy at this yield as the 4330V.
I guess I need to know will the proposed treatement method have a detrimental effect on the mech props of the underlying 4330v?
It seems that the Gas nitriding and the steam temper/oxidisng are at similar temps to the tempering and stress releif. If I push for them to be carried out at the lower end of the ranges, will we be ok?
RE: 4330v treatment for wear and corrosion
The use of 13-8PH will give you much higher toughness. In the H1050 (of maybe even H1100) I would expect over 1000MPa Ys and -50 Charpy values that are higher than for 4330.
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P.E. Metallurgy, Plymouth Tube
RE: 4330v treatment for wear and corrosion
My question is really about the effect of the coating/treatment on the underlying properties of the 4330v, not a materials selection issue, at this stage.
RE: 4330v treatment for wear and corrosion
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P.E. Metallurgy, Plymouth Tube
RE: 4330v treatment for wear and corrosion
RE: 4330v treatment for wear and corrosion
Normally 17-4 is supposed to give a higher Charpy than 4330 at the same level of YS, let alone 13-8.
I am not recommending you, just a comment.
RE: 4330v treatment for wear and corrosion
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P.E. Metallurgy, Plymouth Tube
RE: 4330v treatment for wear and corrosion
Shot or laser-peen, followed by removal of surface roughness to a fine finish by light grinding + Titanium-Nitride [TiN] coating... or perhaps a flame-spray wear/corrosion resistance coating [cobalt (or) cr-Cobalt etc]?
What about one of the CRENS [nitrogen-surface-hardening CRES] alloys now being used in bearings?
Regards, Wil Taylor
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RE: 4330v treatment for wear and corrosion
Thanks for your advice everyone, I shall review this and get back to you.