Corrosion resistance of stainless steel at elevated temperatures

[asimpson]

What would be a good corrosion resistant stainless steel to be used over 800C in an air / steam environment?

Structural strength is not of primary importance as pressures wont be going over 8 bar.

Would martensitic have any advantages over austenitic?

Thanks

 

[asimpson]

Forgot to mention.

Application is steam piping.

Also cost is an issue.

Thanks

 

[TVP]

There are no martensitic grades suitable use at 800 C. Type 310 austenitic stainless is a common high temperature grade.

 

[metengr]

No, martensitic steels have no advantage because of softening and creep strength above 1200 deg F or 650 deg C. At 800 deg C you are going to be limited to Nickel-base alloys, like 800H. I would refer you to ASME B&PV Code, Section II, Part D and search for alloys permitted to 1500 deg F or 820 deg C.

 

[metengr]

I found my copy of B31.1 Power Piping Code and for 1500 deg F service, you can use TP 304H pipe material under ASTM A 376. See Appendix A-8. I would strongly recommend you follow B31.1 for piping. Other stainless steel high temperature pipe grades are not necessarily listed.

 

[asimpson]

Thanks for help