ALL COPPER DOES IS PROMOTE PEARLITE AN ADDITTION OF 0.5 TO 1% WOULD GREATLY INCREASE THE LIKELY HOOD OF A FULLY PEARLITIC MATRIX.
AN ADDITION OF 0.5% CHROME AND 0.2 % MOLY WOULD CREATE VERY STABLE CARBIDES....!!!
i always thought it was down to traceability and assurance.
Definately strict rulings on mechanical tests as well as certain extra tests not needed for other applications.
Eg Westland helicopters qqb671c
is basically AB2 but must be made from ingots from approved supplier. Records of tests...