Material for Steam Valve Spindles

[GordonF]

Hi

We have experimented with various materials for valve spindles operating in steam at 540C including

Nitrided low allow steels (EN41B)
Nitrided 12Cr steels
Incolloy 800 HT

The most successful valve spindles have been a low alloy steel (AISI P20) coated with Stellite 6. We wish to manufacture more of these spindles unfortunately we cannot source AISI P20 readily. Do you know of a supplier of AISI P20 or could you advise of any similar low alloy creep resistant steel suitable for the application?

 

[metengr]

We have used 2.25% Cr - 1% Mo alloy steel overlaid with Stellite 6 with no problems in our MS and turbine stop valves discs. The AISI P20 contains only 1.7% Cr and 0.5% Mo from what I remember, and is a tool steel material.