DIN WB36 steel: ASTM EQUIVALENT?

[JNieuwsma]

Hi folks,

I haven't had any luck with this query on the Valve forum, so I'm hoping some of you materials poeple can help out...

I've come across a requirement for valves of "WB36" steel, specified for a boiler feedwater system at 200 deg. C/30 MPa (approx. 390 deg F/4350 psi). Never having heard of WB36 I did some research and determined that it's a DIN material (EN 1.6368), with no "direct" ASTM equivalent as far as I can tell.

FYI, specified chemical and mechanical properties of WB36 are as follows:
C 0.10-0-17
Si 0.25-0.50
Mn 0.80-1.20
P 0.025 max
S 0.020 max
Cr 0.30 max
Ni 1.00-1.30
Cu 0.50-0.80
Mo 0.25-0.50
Nb 0.015-0.045
N 0.020 max
Al 0.015-0050

Yield 430 N/mm^2 (62 ksi)
Tensile 580-740 N/mm^2 (84-107 ksi)

Questions:
1. To confirm my finding, is there no "direct" ASTM equivalent of WB36 material?
2. What ASTM material is generally specified for such an application?
3. Any other relevant comments or suggestions?

Thanks for the assistance!
Jonathan Nieuwsma

 

[unclesyd]

There appears to be no ASTM equivalent for 15NiCuMoNb5 (WB36). It falls between F12 (WC6) and F22(WC9). There is also some concern about it's in service embrittlement, due to copper precipitation.
Looking at the tables it is strong though somewhat limited in service temperature 450̊C .

I don’t see it except as a forging.

Check the following link.

http://www.tycovalves-na.com/ld/RAILT-0007-EN.pdf

You can just pick out a forged steel valve that meets you presure temperature requirements.

 

[platvoet]

WB36 was (is?) the material desination (steel brand name) of company Thyssen Schulte Werkstoffe GMBH(Dusseldorf in Germany).
It's a high temp. constructional steel for Boiler drums, Pressure vessels, corugated tube (temp max. 500 degree =\Celsius).
Material also known as 15NiCuMoNb5 (1.6368)
ASTM equivalent is unknown.
Regards.