Wear/Erosion resisting alloy- Alloy-718 or any other

[Normankhan]

One Inquiry.
There are 5 vessel-sand separators we use in one of our production units.
We are facing frequent change overs on the down leg spools(Angled straight pipes with 45degree or 90degree) made from SS-316 due to flow of solid pigment (TiO2), sand scouring and small traces of gases. The service life we can get as much as 2 weeks only. We want more service life. The operating parameters for vessel are P= 0.12-0.5bar and T=470-600 OC. we want a wear resistance alloy for such high temp application. In other words high hot hardness. What you suggest the behavior of Inconel-718 if selected in terms of erosion resistance, high hot hardness, performance etc. Can you suggest other alloys beside 718? what about Alloy-625.
Thanks and reply soon
Norm

 

[EdStainless]

Looking at strength/hardness at 1000F It looks like it would be tough to beat 718 if you want to use solid alloy.
Could these be made from cold worked material? There are some options if your add cold work, or even 718 that has been cold worked and direct aged (no anneal).

What diameter are these? I am thinking of coating the inside with an HVOF carbide. You might want to move to a stronger substrate anyway to help the coating work better.

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Plymouth Tube

 

[TVP]

I agree with Ed-- HVOF sprayed coating of tungsten carbide would provide outstanding wear resistance. Alloy 718 has good strength at temperature, but optimal resistance to abrasive wear requires a different microstructure than either Alloy 718 or 625 can have. Either alloy will be better than Type 316 stainless, though.

 

[EdStainless]

This is another option

http://www.haynesintl.com/UltimetAlloy.htm

this alloy is not hard, but has some of the best abrasion resistance of any material available.

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Plymouth Tube