Forging spec steel - pressure vessel grade

[airtight]

Can anyone tell me the common forging spec steel which would be used in the usa. It would be the equivalant of the british spec BS1503-224-490 LT50.This has a tensile of 500 - 650 n/mm2 and a yield of approx 350 n/mm2 .

I have been offered ASTM350 LF2 but its yield and tensile values are not as good.

Thanks in advance. Im on the wrong side of the pond to have the correct books !

Neville

 

[metengr]

airtight;
Forging specifications for pressure vessel fabrication in the US are limited to material specifications in the ASME B&PV Code, Section II. There is no common forging specification, you select the material specification from Section II based on service conditions of the pressure vessel. Be careful with using mechanical stregnth properties to compare materials because allowable stress values are typically used in design-by-rules. You can also design-by-analysis.

 

[SJones]

Why is a withdrawn standard being used? BS 1503 was replaced by EN 10222 Parts 1 to 5. A350 LF2 would be considered the equivalent of 223-490. Don't forget - it will not only be about mechanical properties; chemical composition, specific manufacturing requirements, weldability, supplementary requirements all have to be taken into account. What is the specific application: nozzles, flanges?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[Jughandle]

Airtight,
The following steel forging specifications bracket your stated tensile limits, and may fit your application. Since many of us prefer the British units on our side of the pond, the unit conversion would be 1 MPa = 1 ksi. (kips per square inch’; a kip is 1000 pounds.)

ASTM A350, [try]Grade LF6
Standard Specification for Carbon and Low Alloy Steel Forgings, Requiring Notch Toughness Testing for Piping Components.

ASTM A788
Standard Specification for Steel Forgings, General Requirements

ASTM A668, Class F
Standard Specification for Steel Forgings, Carbon and Alloy, for General Industrial Use

I hope that helps.

Jim Malamas
Mechanical Engineer
Materials Engineer
Stafford, Virginia
540-288-2161

 

[RPstress]

A quick note (on what is no doubt a typo by Jughandle):

1 MPa = 145.0377 psi.
1 ksi = 6.894759 MPa.

145 and 6.895 are usually perfectly accurate enough.