17-4 PH Y/T ratio <0.7, low Yield for H1150
17-4 PH Y/T ratio <0.7, low Yield for H1150
(OP)
Hello
I have a 17-4 PH forging which was heat treated to:
Solution 1900°F for 4 hours
1st Precipitation hardening 1150°F for 4 hours
2nd Precipitation hardening 1150°F for 4 hours
Sometimes the Y/T ratio is ok 0.85-0.9, but sometimes it is 0.6-0.7 which means that the Yield is very low for a certain hardness.
does anyone might have a clue why this happens even in the same heat? And how can I increase the Y/T ratio?.
one chemical composition is :
C 0.026
Si 0.36
Mn 0.92
P 0.019
S <0.001
Cr 15.78
Mo 0.12
Ni 4.54
Cu 3.2
V 0.02
W 0.02
Co 0.03
Nb 0.24
I have a 17-4 PH forging which was heat treated to:
Solution 1900°F for 4 hours
1st Precipitation hardening 1150°F for 4 hours
2nd Precipitation hardening 1150°F for 4 hours
Sometimes the Y/T ratio is ok 0.85-0.9, but sometimes it is 0.6-0.7 which means that the Yield is very low for a certain hardness.
does anyone might have a clue why this happens even in the same heat? And how can I increase the Y/T ratio?.
one chemical composition is :
C 0.026
Si 0.36
Mn 0.92
P 0.019
S <0.001
Cr 15.78
Mo 0.12
Ni 4.54
Cu 3.2
V 0.02
W 0.02
Co 0.03
Nb 0.24





RE: 17-4 PH Y/T ratio <0.7, low Yield for H1150
RE: 17-4 PH Y/T ratio <0.7, low Yield for H1150
Double long time aging can give you some reverse austenite, leading to lower yield. if you need higher yield, and higher Y/T, just aging once, or decease aging temperature.
RE: 17-4 PH Y/T ratio <0.7, low Yield for H1150
Your second age should be 10F below the first, and neither should ever go above 1150F.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: 17-4 PH Y/T ratio <0.7, low Yield for H1150