Steel Grade A-70 Clarification?
Steel Grade A-70 Clarification?
(OP)
We have a tank that the documentation (dating back to the early 1940's) states there is some part of it made with "A-70 FBX" steel. I understand FBX means FIREBOX. However, none of my resources go back far enough to capture what the A-70 spec entails. I'm assuming a carbon steel.
Does anyone know about this material or can point me in the right direction to find out information?
Thanks
~NiM
Does anyone know about this material or can point me in the right direction to find out information?
Thanks
~NiM





RE: Steel Grade A-70 Clarification?
Assuming the A 70 is an ASTM A70 Specification for Low and Intermediate Tensile Strength Carbon steel plate, this specification was withdrawn in 1947 and was replaced with ASTM A285. The ASTM A285 specification contains three grades of carbon steel plates A thru C.
RE: Steel Grade A-70 Clarification?
I might be able to track down a copy of this particular ASTM standard. One of my former mentors, who is now in the big met lab in the sky, used to keep old ASTM Standards, which I now have inherited for my own library. When I get back to the office on Thursday, I will check the archives.
RE: Steel Grade A-70 Clarification?
What I'm really looking for are the allowed stress values. The steel was used to construct propane bullets back about 1942-43. We're looking to set minimum temperatures on these, taking into account brittle fracturing as a possibility.
Any help you can provide will be greatly appreciated.
Thanks again!
~NiM
RE: Steel Grade A-70 Clarification?
I've seen a lot of this material on fireboxes and ovens.
You can get copy of the ASTM A70 Standard from:
Global Engineering documents globalcustomerservice@ihs.com Phone: 800-854-7179 or 303-397-7956
Or
http://www.lindahall.org/
They may also be able to supply you the ASME Code UCS tables for this material.
RE: Steel Grade A-70 Clarification?
~NiM
RE: Steel Grade A-70 Clarification?
It is your lucky day. I contacted one of my fellow main committee members at the NB, and they sent me a copy of the allowable stress values for ASTM A-70 S1 carbon steel plate material from the 1945 Edition of the ASME B&PV code;
A-70 S1
allowable stress temp
11 Ksi ambient to 700 deg F
10 Ksi 750 deg F
8 Ksi 800 deg F
6.750 Ksi 850 deg F
5.5 Ksi 900 deg F
4 Ksi 950 deg F
RE: Steel Grade A-70 Clarification?
~NiM
RE: Steel Grade A-70 Clarification?
13750 -20 to 650
13050 up to 700
11550 750
9900 800
8250 850
6600 900
4950 950
3400 1000
-InspEngr
RE: Steel Grade A-70 Clarification?
That information will work too. We'll run the figures from both sets just for comparison.
thanks
~NiM
RE: Steel Grade A-70 Clarification?
You are correct in those years ASME VIII used a 5.0 factor of safety. API-ASME used 4.0.
Historically, ASME and API-ASME were never same Code. They were always separate Codes intended for different industry segments. API-ASME was withdrawn in early or mid-1950's after ASME was reduced to a 4.0 factor of safety. No reason to have two Codes with same F of S. The intro to API-510 gives additional info.
Steve Braune
Tank Industry Consultants
www.tankindustry.com
RE: Steel Grade A-70 Clarification?
~NiM