17-4PH 15-5PH 630 631 1.4542 1.4568 Stainless Steel Coil

17-4PH 15-5PH 630 631 1.4542 1.4568 Stainless Steel Coil

17-4PH (UNS S17400 / AISI 630 / 1.4542)
Standards: ASTM A693, JIS SUS630, EN 1.4542.
Chemical composition: Cr: 15.0–17.5%, Ni: 3.0–5.0%, Cu: 3.0–5.0%, Nb: 0.15–0.45%.
Performance: Highest strength after heat treatment (e.g. H900 state yield strength ≥1070 MPa).
Corrosion resistance is comparable to 304, suitable for moderately corrosive environments.
Applications: Aerospace components, chemical equipment, nuclear waste containers, mechanical parts.

15-5PH (UNS S15500)
Standard: ASTM A564
Chemical composition: Cr: 14.0–15.5%, Ni: 3.5–5.5%, Cu: 2.5–4.5%, Nb: 0.15–0.45%.
Performance: Strength is similar to 17-4PH, but the high temperature stability is slightly better. Outstanding corrosion fatigue resistance.
Application: springs, valve components, turbine blades.

631 (AISI 631 / UNS S17700 / SUS631)
Standard: ASTM A693 (American Standard), JIS SUS631 (Japanese Standard).
Chemical composition: Cr: 16.0–18.0%, Ni: 6.5–7.75%, Al: 0.75–1.5%.
Performance: Austenite-martensite dual-phase structure, high strength after heat treatment (yield strength ≥1030 MPa). Excellent stress corrosion resistance.
Application: high-strength springs, fasteners, pressure vessels.