Maraging steels: Durnico (Durimphy, NiMark 300), Durinox (Ultrafort) and Phynox (Elgiloy)
Martensitic, hardenable premium steels in the form of thin strips are a renown speciality of Lamineries MATTHEY, where two different maraging steels are rolled: Durnico, X2NiCoMo18-9-5, 1.6358 (Durimphy; NiMark 300) and Durinox, X2CrNiMo10-10-5, 1.6908 (Ultrafort). A slightly higher mechanical strength can be achieved with Durnico. Corrosion resistance of Durinox exceeds that of Durnico, though is slightly lower than that of stainless steel 1.4435, 316L. The alloys provide good formability of the parts, are very high fatigue strength, whilst critical cutting edges remain smooth. After solution annealing at elevated temperatures (typically 850 to 1,000°C), they can be hardened for several hours at about 480 °C in order to achieve high strengths around 2,000 N/mm2.The hardening process occurs through the presence of very stable intermetallic compounds of type Ni3Ti or Fe2Mo, whereas no deformation (distortion) of the treated parts occurs. Hardening can also occur from the prior hard-rolled temper and since the hardening temperature does not lead to re-crystallization, the material enjoys even greater tensile strength.