Degraded yield strength of UNS S31803

[maatjie_mike]

Hi All

I am completing pipe design calculations using UNS S31803 (65ksi yield) in an operating temperature range of -4F to 250F. I am trying to account for the shift in Young's modulus and yield strength at the elevated temperatures but need some advice.

ASME II Part D table Y-1 gives the temperature adjusted yield strength for a range of materials but unfortunately UNS S31803 is not on that list. Section 7-230 of ASME II states the guidelines for grade substitution (material composition needs to meet all the limits of the substituted material). There is a material that meets all the requirements except for N (table y-1's material specifies 1N and UNS S31803 has 0.08-0.2)

Can I use the adjusted yield for the material in Y-1 for UNS S31803?

Also is there any other standard that will give me the adjusted yield for UNS S31803 (I cannot find it in US DOT/FAA published "Metallic Materials Properties Development and Standardization(MMPDS)")

Thanks in advanced

 

[XL83NL]

Not sure what the issue is. S31803 (which is very similar to S32205) has the yield listed in table Y-1 as a function of temp.
Chart HA-5 applies to find related shift in Young's modulus as a function of temperature.

I'm looking at the 2019 edt., which is current.

Huub
- You never get what you expect, you only get what you inspect.

 

[maatjie_mike]

Hi X:83NL,

Thanks for the feedback. The problem is the Nitrogen content for S31803 does not match the Nitrogen content for S32205. Basically what I am asking is can I use S32205 inspite of this and if so why?

Kind regards

 

[XL83NL]

Im not sure if I understand your issue correctly. Table Y-1 lists the yield strength (and fig. HA-5 the E-modulus) as a function of T for S31803 (in the current edt of ASME ASME II), which to me seems to be what you're looking for. Then why look for a substitute material instead?

Huub
- You never get what you expect, you only get what you inspect.