ASTM A471, Class 7? 1

[specialu77]

The ASTM A471 spec (forging spec) currently has classes 1-6, and then 10-14. I have a customer who is requesting an ASTM A471 Class 7.

I suspect that it might have once existed, but was removed in the more recent versions of the spec. Does anybody know if there was ever a time where class 7 might have existed? And if so, where can i find its spec info.

 

[metengr]

The predecessor to ASTM A 471 was A 294 (which was discontinued in 1988). I believe there was a Class 7 in A 294. I need to verify this when I can get access to my files.

 

[metengr]

Ok, I was able to gain access to my EPRI web site. LP rotor forgings were specified under ASTM A 470, with Classes 2-7 or earlier forgings were supplied under ASTM A 293 Classes 2 thru 5.

HP rotor forgings were supplied as ASTM A 293 Class 6 or ASTM A 470 Class 8.

For disc forgings, they were supplied as ASTM A 294 in either Grades A, B and C with Classes 1-7.

 

[specialu77]

Excellent. Thank you.

Would you also happen to have the chemical comp. and the physical properties for A294 CL7? (our spec log doesn't appear to have that spec.)

I've already given the go ahead to our purchasing guys to quote A471 CL6. But if you have the C%, Mn%, and yield strength of the A294, I would like to compare that with A471 CL6. Thanks again.

 

[metengr]

ASTM A 294 Class 7

Chemical composition has to be specified by the purchaser and can be one of three Grades A, B or C. Most likely Grade B or C, Which Grade are you interested in?

Regarding Class 7 Mechanical Properties

UTS 140-160 Ksi
YS 125 Ksi min
%E (2") 15% min

RA 40% min

Hardness 285-331 BHN

 

[specialu77]

Since the customer specified ASTM A471 CL7, I really can't speak for them what grade to use... BUT if those are the mechanical properties of A294, then A471 CL6 should be sufficient. Here's the mechanical properties for A471 CL6

UTS 140
YS 130-150
%E(2") 15%
RA 43%
BHN N/A

And thanks for the speedy response by the way.