ASTM A 387 Gr. 5 Temper Embrittlement

[DBreyer]

Dear all,

in one of my companies material specifications for pressure vessels I found a requirement for ASTM A 387 Gr. 5 having a J-Factor <150.
I am well aware of the susceptibility of Gr 11 and Gr 22 in high temperature service to temper embrittlement but could not find any document mentioning the same behaviour for 5%Cr-Mo steel.

Have you encountered similar requirements or are you aware of a technical basis for limiting the analysis?

Thanks for your help

Daniel Breyer
Inspection Engineer

http://lnkd.in/dFcQA-w

 

[metengr]

I can say that I have not seen such specific restrictions for the Cr-Mo family above 5%Cr. Keeping residuals low, however, is always a good thing when it comes to notch toughness, creep or creep fatigue resistance in service. This is really based on my experience with CSEF steel performance.

 

[WKTaylor]

DBreyer...

Your company's J<150 limitation comes directly from the ASTM A387 SUPPLEMENTARY REQUIREMENTS... which adds fair explanation to the spec, various elements.

SUPPLEMENTARY REQUIREMENTS
Supplementary requirements shall not apply unless specified in the order. A list of standardized
supplementary requirements for use at the option of the purchaser is included in Specification
A20/A20M. Several of those considered suitable for use with this specification are listed below by
title. Other tests may be performed by agreement between the supplier and the purchaser.

Might also want to check-out ASTM A20 Standard Specification for General Requirements for Steel Plates for Pressure Vessels

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[DVWE]

WKTaylor,

Those supplementary requirements only apply to Gr 21 and 22, as described in the header.

However, I agree with metengr that tramp element control is always a good thing for low-alloy steels.