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.

Phynox, UNS R30003, (Elgiloy) is an austenitic hardenable superalloy on cobalt basis (40 % Co, 20 % Cr, 16 % Ni and 7 % Mo). Its mechanical strength may exceed 2,600 N/mm2, after the hardening. The maximum reachable tensile strength depends however significantly on the preceding cold deformation. It is non-magnetic, very resistant to corrosion (better results than any other stainless steel) and temperature resistant. Its high elasticity modulus (220 kN/mm2) combined with an elongation limit that can be over 1,800 N/mm2 makes Phynox an exceptional alloy for spring application. Lamineries MATTHEY SA delivers Phynox strips according the following standards: ASTM F1058 (surgical implants), ISO 5832-7 (surgical implants), AFNOR NF S 90-403 (surgical implants), AMS 5875, AMS 5876 and NACE MR0175.

Maraging steels: Durnico (Durimphy), Durinox (Ultrafort) and Phynox (Elgiloy) strips and foils
DescriptionTechnical file
Durnico┬« - Maraging Steel / ~ 1.6358 / ~ K93120 / ~ K93160 / ~ X2NiCoMo18-9-5    Durnico_C.pdf
Durinox┬« - Maraging Steel / Ultrafort┬« 6908 / 1.6908 / X2NiCrMoTi10-10-5     Durinox_C.pdf
Phynox┬« - CoCr20N16Mo7, DIN 2.4711, ISO 5832-7, ASTM F1058, R30003 / R30008    Phynox_C.pdf
Phytime┬« - Maraging Steel / X2NiCoMo18-16-5  
Duratherm┬« 600 / 2.4781  

See also dimensional tolerances and material safety datasheet (MSDS) :