UG-85(b)

[Genetix]

Dear respected experts,

I would like to have an inquiry regarding the definition of heat treatment as per UG-85(b) of ASME BPVC Sec VIII Division 1. As per UG-85(b). Heat treatment for carbon and alloy steel is considered as thermal treatment exceeding 480°C. I'm just curious where this do ASME derived this 480°C. Is this the lower critical transformation temperature for carbon and low alloy steel.

Hoping for someone will clarify.

Thank you and good day.

 

[r6155]

See DEFINITIONS in SA-941

Regards
r6155

 

[lslcpfcc]

the HEAT treatment condition of the test coupon is different from the PWHT for products.
the requirement of UG-85(b)is specified that when the impact test is required by ASME viii-1，the heat treatment of test coupon plates must be same with the plates which will be fabricated the produces. this heat treatment condition indicates the finial deliver condition，including hot rolling (control rolling), Normalizing, quench+temper.
This issue has been discussed many times in the ASME code thread of this forum,you can search the topic in the forum, and the ASME commission given a very clear interpretation in earlier year. you can find it in the web.

 

[Genetix]

Sorry my bad. Im referring to UCS-85(b) not UG-85

 

[metengr]

480 deg C is not the lower critical transformation temperature for carbon or low alloy steel. This temperature was selected by the code committee as a conservative temperature where at or above this temperature hot working or PWHT can alter mechanical properties.

 

[lslcpfcc]

please search the Key-word “UCS85 interpretation ”, you will find many discussion and official interpretation issued by ASME commission refer to this clause, Read them carefully, you will find the answers.

 

[granQC]

Hi!
In my opinion, the 900degF (480degC) pertains to the minimum temperature where heat treatment takes place (e.g. applicable to Aging treatment/Precipitation Hardening) on a material. The Code 'maybe' simply specify it to consider not only the common heat treatment range-from 1100degF (595degC).

Ciao!