RE: Secondary creep laws

From: <Mark>
Date: Thu May 17 2001 - 13:49:00 EDT

Babara

Reference Marks Standard handbook for mechanical engineers Refer
Table 5.1.6 Stresses for Given Creep Rates and Temperatures* This does not specifically give stresses for ASTM A335 P11 but you will need to match its material composition with table 5.1.6

Mark Upston
M&M Design Services Ltd co
1704B Llano st , #249
Santa Fe
NM 87505

email: mmwind@cnsp.com

-----Original Message-----

From: James, Barbara [mailto:bjames@mitsuibabcock.com] Sent: Thursday, May 17, 2001 8:31 AM
To: 'PipingDesign@yahoogroups.com'
Subject: [PipingDesign] Secondary creep laws

Hi from one of the lurkers.

I am undertaking a creep life study for a steam line on a refinery.

I have completed the pipe stress analysis using PSA5 and have the pipe moments and forces from the BS806 Hot Stress case (DW + Pressure + Thermal expansion).

Obviously, I also have the stresses but these include the SIFs calculated
by the code which calculate peak stresses rather than the re-distributed

stresses.

In order to calculate the re-distributed stresses, I need to know the material constants for the secondary creep law. e.g Norton Law : Epsilon = B * Sigma^n

Epsilon = creep strain rate
Sigma = stress
B and n are material constants.

Does anybody know where I can find the material constants B and n? The material is ASTM A335 P11.

Can anyone recommend good text books for creep behaviour?

Thanks

Barbara James

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Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Received on Thu May 17 13:49:00 2001

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