17-4PH is a precipitation-hardened stainless steel, also known as 630 stainless steel, which derives its name from the 17% chromium and 4% nickel in its composition. In addition, 17-4PH precipitation hardening stainless steel contains elements such as copper, vanadium, and molybdenum, which can be heat treated and cold-treated to obtain excellent mechanical properties and corrosion resistance.
17-4PH composition analysis
C: ≤0.07, low carbon content, which can reduce the hardness and strength of the material, but helps to improve the processing properties of the material.
Si: ≤1.00, the increase of silicon content helps to improve the strength and hardness of the material, but also reduces the plasticity and toughness of the material.
Mn:≤1.00, the increase of manganese content can improve the strength and hardness of the material, and help to improve the fatigue resistance.
P:≤0.035, too high phosphorus content will reduce the strength and toughness of the material, but in the appropriate range, phosphorus content can improve the processing properties of the material.
S:≤0.030, too high a sulfur content will reduce the toughness and ductility of the material, and may lead to brittle fracture.
Ni:3.00-5.00, nickel is an important element in stainless steel, and can improve the corrosion resistance and strength of the material.
Cr:15.0-17.5, chromium is the main alloying element in stainless steel, can improve the corrosion resistance and hardness of the material, and help to improve the high-temperature strength of the material.
Mo:-, the molybdenum content is 0, which may be one of the characteristics of this stainless steel.
Cu:3.00-5.00, with high copper content, improves the strength and hardness of the material and contributes to corrosion resistance.
Nb:0.15-0.45, the right amount of niobium content can improve the strength and hardness of the material, and help to improve the high-temperature performance of the material.
ASTMS17400, ASTM A564 630, UNS630
The tensile properties data of 17-4PH are as follows:
Tensile strength: approx. 1275 MPa
Yield strength: approx. 1160 MPa
Elongation: approx. 12%
Because of its excellent mechanical properties and corrosion resistance, 17-4PH is widely used in aerospace, medical devices, and marine engineering. In the future, the development trend of 17-4PH is mainly to improve its corrosion resistance, enhance its processing performance and reduce costs. In addition, with the development of material science, 17-4PH may be replaced by more advanced alloys.