Fracture toughness for S154 (S96).
Fracture toughness for S154 (S96).
(OP)
Can anyone tell me a (room temp) fracture toughness (KIc, Kq) for the UK corrodible aerospace steel spec S154 (or S96)?? There's nothing in the Metallic Materials Data Handbook.
In hope,
Richard Perry.
In hope,
Richard Perry.





RE: Fracture toughness for S154 (S96).
RE: Fracture toughness for S154 (S96).
Here's a bunch of stuff about it:
Element Min % Max %
C 0.27 0.35
Si 0.15 0.35
Mn 0.45 0.70
P - 0.025
S - 0.015
Cr 0.50 0.80
Mo 0.45 0.65
Ni 2.3 2.8
Al 0.015 0.05
B-basis Ftu = 906 MPa (131 ksi) & t2 = 711 MPa (103 ksi) (t2 = 0.2% proof stress).
Izod is 54 J at 6" thick.
B.S. S154 spec. requirements are:
Ftu 880 to 1080 MPa (128 to 157 ksi), t2 690 MPa (100 ksi) min, e = 12% min, Izod 40 J min.
Hardness: 255 to 321 HB and 270 to 340 HV as hardened and tempered.
In the softened condition (reached by heating at 650 C (1200 F)) hardness must be <= 248 HB (Ftu =~ 120 ksi?).
Heat treat (durations unspecified).
Harden: 850+-10 C (1560+-20 F), cool in oil.
Temper: 600 C (1110 F), cool in air.
RE: Fracture toughness for S154 (S96).
Thread330-24020
References for this equation include ASM HANDBOOK Volume 19 Fatigue and Fracture and Barsom & Rolfe's book, Fracture and Fatigue Control in Structures: Applications of Fracture Mechanics, Third Edition, published by ASTM. You can even download portions of this for free using the following link:
http://www.astm.org/BOOKSTORE/MNL41PDF/
RE: Fracture toughness for S154 (S96).
RE: Fracture toughness for S154 (S96).
I looks like there's at least some correlation between Izod and Charpy...any feel for what risk there may be in using Izod energies in place of CVN ones for estimating KIc/d, etc.?
RE: Fracture toughness for S154 (S96).
RE: Fracture toughness for S154 (S96).
RE: Fracture toughness for S154 (S96).
ESDU in the UK is usually the best source of data on these steels, but you need a subscription to use it.
http://www.esdu.com
Probably the best approach would be to do a limited amount of testing, backed by ESDU's data/correlations for steels of this type.
RE: Fracture toughness for S154 (S96).