P355NH AND P355QH1 DIFFRENCE?

[Krishna_Manyam]

Dear Experts,

Kindly advice on below,

P355QH1(Un assigned group as per ASME IX)where as P355NH assigned group as per ASME IX?
BOTH HAVE SAME CHEMICAL AND MECHANICAL PROPERTIES.

 

[Dhurjati Sen]

Cannot replace an assigned material with an unassigned one.

DHURJATI SEN
Kolkata, India

 

[DBreyer]

QH is quenched and tempered weras NH is normalised