Charpy Impact Properties for F11 CrMo Steel
Charpy Impact Properties for F11 CrMo Steel
(OP)
I am looking for typical data for A182, F11, Class 1 forgings in about 4 inch section thickness. Anywhere in the temperature range -20F to +70F, or else a transition temperature. Thanks.





RE: Charpy Impact Properties for F11 CrMo Steel
RE: Charpy Impact Properties for F11 CrMo Steel
This is based on test locations as specified in A182 for new forgings and does not imply that you will obtain same values on actual parts in any location, especially forging in use and never subject to testing.
RE: Charpy Impact Properties for F11 CrMo Steel
RE: Charpy Impact Properties for F11 CrMo Steel
-20F sounds like a normal MDMT in my neighbourhood, but the part operates at up to 950F. I see some microstructural degradation in the hottest surfaces, but no difference in hardness between hottest and coldest regions. One set of impacts @ -20F are well below 15/12 ft-lb, but does that necessarily mean there may be some temper embrittlement?
RE: Charpy Impact Properties for F11 CrMo Steel
RE: Charpy Impact Properties for F11 CrMo Steel
RE: Charpy Impact Properties for F11 CrMo Steel
Why in heavens are you worried about interpreting notch toughness values with a component that was manufactured for elevated temperature service with no original notch toughness requirements in the material specification? The F11 and F22 (or P11 and P22) are supplied with no notch toughness requirements because they are operating well above the DBTT. Even if you have some manifestation of thermal embrittlement over the course of many thousands of hours of elevated temperature service, your main concern should be creep damage, not worrying about notch toughness. This is why ASME Section I components have no notch toughness requirements for application in elevated temperature service.
The above items are typically supplied as either annealed or normalized and tempered (N&T). Even a N&T thermal treatment is not going to improve notch toughness. When Section II endorsed this material for use in elevated temperature service back in the 1950's, the concern was adequate creep strength not low temperature properties.
RE: Charpy Impact Properties for F11 CrMo Steel
I get all of that, except that one of the main concerns re:embrittlement is during a potential hydrotest at ambient temperature. And actually, the operating temperature cycles, so low temperature toughness might be of some concern. Having said that, however, I am sure this part was not ordered with impact requirements.
This is a post-mortem and I just want to be able to comment intelligently on Charpy results that were requested by the client. (I have already documented the creep damage that killed this component).
RE: Charpy Impact Properties for F11 CrMo Steel
There are ways around this. You can even use ASME Section VIII, Div 1 curve A and prewarm the water for pressure testing, if necessary.
RE: Charpy Impact Properties for F11 CrMo Steel
RE: Charpy Impact Properties for F11 CrMo Steel