What is 17-7ph precipitation hardening stainless steel?

AISI 631 stainless steel, also known as 17 - 7PH, is a precipitation hardening stainless steel, belonging to austenite-martensite precipitation hardening stainless steel. It contains 15-17% Cr, 6.5-8.5% Ni, etc. It has excellent strength and hardness, can be improved by heat treatment, has strong corrosion resistance, is suitable for high-load components, and is widely used in chemical, marine, medical and other fields.

17-7PH stainless steel cold-rolled bars are often used to manufacture high-strength components with strict requirements on acid, alkali and salt corrosion resistance, such as the last stage moving blades of steam turbines. It is suitable for structural parts with working temperatures below 300°C in corrosive environments.

AISI 631 Stainless Steel Round Bar Chemical Composition
The chemical composition is roughly as follows:
Carbon (C): 0.05 - 0.10%
Silicon (Si): Maximum 0.80%
Manganese (Mn): Maximum 1.00%
Phosphorus (P): Maximum 0.04%
Chromium (Cr): 15.0 - 17.0%
Nickel (Ni): 6.5 - 8.5%
Aluminum (Al): 0.15 - 0.40%
Copper (Cu): 3.0 - 4.5%

1.4568 (Alloy 17-7PH®) steel bar Physical properties
Density: about 7.67kg/m³
Melting point: 1415 - 1450℃
Specific heat capacity: 460.6J/(kg·℃)
Magnetic properties: Magnetic

17-7PH, AISI 631, 1.4568 Stainless Steel rod Mechanical properties
Solution treatment: 955℃, rapid cooling, aging: after solution treatment, aging treatment temperature is 510℃, air cooling,
Tensile strength σb(MPa): ≥1030
Yield strength σs(MPa): ≥1280
Elongation δ5(%): ≥6
Sectional shrinkage ψ(%): ≥10
Hardness: ≤388HBW; ≤41HRB
Solution treatment: 760℃, rapid cooling, aging: after solution treatment, aging treatment temperature is 565℃, air cooling,
Tensile strength σb(MPa): ≥965
Yield strength σs(MPa): ≥1070
Elongation δ5(%): ≥6
Sectional shrinkage ψ(%): ≥25
Hardness: ≤352HBW; ≤38HRB

631 17-7PH 1.4568 Stainless Steel Bar Formability
It has good formability and can be made into various complex parts through deep drawing, stretching and other processing techniques.