TY - JOUR
T1 - 17-4 Precipitation-Hardening Stainless Steel
T2 - Soft-Tough Heat Treatment Mechanism and Thermal Fatigue Characteristics
AU - Hsieh, Ping Yu
AU - Wu, Bo Ding
AU - Hung, Fei Yi
N1 - Publisher Copyright:
© 2024 by the authors.
PY - 2024/12
Y1 - 2024/12
N2 - This study selected 17-4PH (Type 630) precipitation-hardening stainless steel as the raw material. After subjecting the material to precipitation hardening and softening heat treatments, the effects of these treatments on the microstructural characteristics and mechanical properties were investigated, along with a thermal fatigue test. The results showed that after the precipitation hardening heat treatment, the ultimate tensile strength and hardness of 17-4PH stainless steel increased. However, the ductility was around 2%, indicating a severe brittleness effect, which is unfavorable for ordnance applications. A double aging treatment for 12 h resulted in a combination of softness and ductility, with an ultimate tensile strength of 900 MPa, ductility of 26%, and hardness HRC 28. These material properties are suitable for cold forging in ordnance and other applications. In addition, a thermal fatigue test was conducted on the softened 17-4PH material from 750 °C to room temperature. After 3000 thermal cycles, there was no significant change in material properties, ensuring it can withstand 3000 rounds of gunfire in a barrel with excellent durability. Furthermore, XRD and fracture surface analysis confirmed that the softening mechanism of 17-4PH stainless steel and its high-temperature phase stability could provide a reference for cold forging and high-temperature applications.
AB - This study selected 17-4PH (Type 630) precipitation-hardening stainless steel as the raw material. After subjecting the material to precipitation hardening and softening heat treatments, the effects of these treatments on the microstructural characteristics and mechanical properties were investigated, along with a thermal fatigue test. The results showed that after the precipitation hardening heat treatment, the ultimate tensile strength and hardness of 17-4PH stainless steel increased. However, the ductility was around 2%, indicating a severe brittleness effect, which is unfavorable for ordnance applications. A double aging treatment for 12 h resulted in a combination of softness and ductility, with an ultimate tensile strength of 900 MPa, ductility of 26%, and hardness HRC 28. These material properties are suitable for cold forging in ordnance and other applications. In addition, a thermal fatigue test was conducted on the softened 17-4PH material from 750 °C to room temperature. After 3000 thermal cycles, there was no significant change in material properties, ensuring it can withstand 3000 rounds of gunfire in a barrel with excellent durability. Furthermore, XRD and fracture surface analysis confirmed that the softening mechanism of 17-4PH stainless steel and its high-temperature phase stability could provide a reference for cold forging and high-temperature applications.
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U2 - 10.3390/ma17235851
DO - 10.3390/ma17235851
M3 - Article
AN - SCOPUS:85211789890
SN - 1996-1944
VL - 17
JO - Materials
JF - Materials
IS - 23
M1 - 5851
ER -