1.4501

X2CrNiMoCuWN25-7-4

The 1.4501 (X2CrNiMoCuWN25-7-4) is a duplex steel: about half [[glossary:austenit|austenite]], half [[glossary:ferrit|ferrite]]. That gives you double the strength of austenitic grades and very good chloride resistance (high PREN). The catch: The phase balance tips during welding if the heat isn't exactly right. Typical analysis: 0.02 % C, 0.5–1 % W, 0.2–0.3 % N, 25 % Cr, 0.8 % Mn, 3.5 % Mo, 7 % Ni, 0.4 % Si.