The yield strength of 17-4PH mainly depends on the aging temperature, ranging from 800–1200 MPa. Lower aging temperatures correspond to higher yield strength.
Yield Strength at Different Aging Temperatures (Typical Process: 4 hours hold + air cooling):
480°C aging: ~1200 MPa, higher strength.
550°C aging: ~1050 MPa, balanced strength and toughness.
590°C aging: ~930 MPa, better toughness.
620°C aging: ~800 MPa, good toughness, suitable for low-temperature applications.