Allowable Stress Values for 17-4 PH stainless steel (H1150 vs. H1150M)
Allowable Stress Values for 17-4 PH stainless steel (H1150 vs. H1150M)
(OP)
I am currently designing a line blank component using SA-564 Type 630 (a 17-4 PH stainless steel) in the H1150M age hardened condition. However, ASME Section II, Part D, Table 1A only lists maximum allowable stress values (S) for SA-564 Type 630 in the H1150 age hardened condition. No allowable stress values are listed for H1150M!
My question is:
Can I use the H1150 maximum allowable stress values (S) listed in ASME Section II, Part D, Table 1A when designing a component made from H1150M?
Note: SA-564 Type 630 H1150 appears as line 22 on page 46 of ASME Section II, Part D, Table 1A (2011 verision).
I realize that the elevated UTS and YS of H1150M is less than H1150, however there are no mechanical properties for H1150M or H1150D in ASME Section II, Part D. I’ve always considered H1150M and H1150D as sub-conditions of H1150 but I’m not 100% positive that the values listed for H1150 in Table 1A are intended to apply to both H1150M and H1150M as well.
Thanks in advance for any light you can shed on this request for clarification.
My question is:
Can I use the H1150 maximum allowable stress values (S) listed in ASME Section II, Part D, Table 1A when designing a component made from H1150M?
Note: SA-564 Type 630 H1150 appears as line 22 on page 46 of ASME Section II, Part D, Table 1A (2011 verision).
I realize that the elevated UTS and YS of H1150M is less than H1150, however there are no mechanical properties for H1150M or H1150D in ASME Section II, Part D. I’ve always considered H1150M and H1150D as sub-conditions of H1150 but I’m not 100% positive that the values listed for H1150 in Table 1A are intended to apply to both H1150M and H1150M as well.
Thanks in advance for any light you can shed on this request for clarification.





RE: Allowable Stress Values for 17-4 PH stainless steel (H1150 vs. H1150M)
I agree that taking the ratio of room temp TS between SA-564 Type 630 H1150M to H1150 would give me a ratio I could then apply to the elevated temperature values listed in ASME Section II, Part D (Table 1A).
Note that since H1150M is not listed in ASME Section II, Part D so I will use the values listed in ASME Section II, Part A.
SA-564 Type 630 (min TS - Table 4: Mechanical Test Requirements After Age Hardening Heat Treatment):
min TS of H1150M = 795 MPa
min TS of H1150 = 930 MPa
Ratio of H1150M : H1150 = 795 : 930 = 0.855.
Also note that the TS for H1150 listed in ASME Section II, Part D (Table 1A) is non-mandatory and is superseded by ASME Section II, Part A.