Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
(OP)
Three part question:
1. Is there an index or list that cross references AISI materials with ASME Boiler tube materials.
2. Does anyone have the fracture toughness modulus for SA 213 T11 (I did a ballpark estimate by using leak before break criteria - but I don't trust the value).
3. I could also use the value of Kth (fracture toughness threshold value for fatigue analysis) - or even better yet - if someone could point me to a load vs. CGD (crack gage displacement) graph.
I guess if all else fails, I could use a charpy test to estimate Kic for a BCC mtl.
Thanks To All (oh the things I get myself into in my free time . . .)
1. Is there an index or list that cross references AISI materials with ASME Boiler tube materials.
2. Does anyone have the fracture toughness modulus for SA 213 T11 (I did a ballpark estimate by using leak before break criteria - but I don't trust the value).
3. I could also use the value of Kth (fracture toughness threshold value for fatigue analysis) - or even better yet - if someone could point me to a load vs. CGD (crack gage displacement) graph.
I guess if all else fails, I could use a charpy test to estimate Kic for a BCC mtl.
Thanks To All (oh the things I get myself into in my free time . . .)





RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
Yes, to your first question. A majority of the ferrous and nonferrous materials that are accepted for use by ASME B&PV Code have a UNS No that can be used to cross reference certain Grades of Steel listed by AISI or other Standards. The web site below contains some background information on the development of the Unified Numbering System;
http:/
The book below can be used to cross reference UNS No with ASTM, JAE and AISI grades of metals;
Metals & Alloys in the Unified Numbering System, 10th Edition
Published September 2004, Paperbound, ISBN: 0-7680-1488-3
I was curious as to the reason you need fracture toughness data for SA 213 T11 material. Typically, the Cr-Mo materials supplied in tube or pipe grades are used in moderate to elevated temperature service so fracture toughness is not something that is commonly needed in design.
Most likely, you will need to either have actual fracture toughness testing performed on this material or you can have Charpy impact testing performed on this material (cheaper cost), and convert to an equivalent KIc fracture toughness value. However, I would not use an equivalent KIc for design purposes.
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
The tube extends through the roof into the convection pass of the boiler. There is a temperature difference between the header and roof (saturation vs. superheat temp) and thus differential expansion. The simple anwser was that the boiler components are 33 years old and overdue for replacement - but I was curious to see what a failure analysis would give - I would not look at designing the component in this method but it is an interesting exercise to go through.
Anyway - I am getting closer to the solution now - Cheers.
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
Thanks for the follow-up information. According to your post, what you really need to be concerned with is creep-fatigue crack propagation because most likely from the scenario you described the mode of crack propagation is creep-fatigue. The fracture toughness would only come into play during conditions where that cracked tube is subjected to a pressure test with water, where the water temperature is below the ductile to brittle transition temperature of the T11 tube. Under normal operating conditions, the tube metal will contain much higher toughness in comparison to room temperature pressure testing.
Under normal service conditions, the crack will propagate until the remaining ligament thickness can no longer sustain internal pressure or thermal/mechanical bending stresses in the tube drive the crack thru wall.
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
Any chance of sperodization with a T11 material? I would doubt it because of the chrome - but I thought I would ask. If I remember correctly the carbon would be in the right range (up to AISI 1050 or so for spheriodization?). ANyway, that all for now.
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
RE: Fracture Toughness SA-213 T11 (1.25 Cr 1/2 Mo)
One more thought - if anyone has an RT NDT temp for sa 213 t11 i could take the fracture mechanics approach further. Although I would still need a loading vs. crack gage displacement test to be accurate - although this would be taking things a bit far.
Cheers to all the help!