17-4 H1150

17-4 H1150 (UNS S17400, EN 1.4542, Alloy 630), is a martensitic stainless steel containing 15-17.5% chromium (Cr), 3-5% nickel (Ni), and 3-5% copper (Cu). 17-4 is precipitation hardened (PH), a heat treatment process that increases its strength and hardness. 17-4 Condition H1150 is achieved by further heat treatment of Cond A. This involves aging at 620 °C (1148 °F) for 4 hours. The result of this aging process is a balance of strength, corrosion resistance, and improved mechanical properties over Cond A. As with all martensitic stainless steels, 17-4 H1150 is magnetic.