What are the hardening methods for HC276, the material used for valve internals? Seeking advice
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I would like to ask the experts on this forum: the material of the valve internals is HC276. These internals are used in PTA processes in contact with acetic acid containing metal ions and crystal particles. How can we ensure that these valve internals are both corrosion-resistant and have increased hardness? What are the common methods for hardening such materials? Have you used chromium carbide surface hardening? How effective is it?
I personally think that this type of medium, with both corrosion and wear caused by crystal particles, presents significant challenges. Chromium carbide hardening does not fully solve the problem; moreover, chromium carbide is usually applied as a coating on the valve core and valve seat, and the thickness of this coating cannot be too great. It is also costly, and its performance is not ideal. In my opinion, for such conditions, it might be worth trying imported ceramic materials
Isn’t the acetic acid on PTA used with a soft seal?
My knowledge is limited: ceramic valves should be more expensive, and this valve is an eccentric rotary valve; typically, ceramic ball valves use V-shaped balls, so the type of ball valve differs. On-site specifications are quite restrictive, and significant technical discussions are required when modifying valve types.
For the pneumatic ball valve used during feeding, since the mother liquor contains metal particles such as cobalt and manganese, a hard-seal type is selected.
Looking at the specifications, metal might be more expensive sometimes; there are also ceramic variants. I can discuss this further with you regarding zx062819
HA-C already has good hardness and corrosion resistance; it is likely difficult to further harden its surface.
Come and learn* it; I’ve never been exposed to a similar process
Which grade of material should be used for surfacing? Could you please be more specific? Thank you.
Hastelloy HC276 is corrosion-resistant, but its hardness or wear resistance cannot be improved through subsequent treatment methods. Generally, the HRC hardness of C276 is between 22 and 23. Spraying chromium carbide or tungsten carbide, etc., results in high brittleness.