X5CrNiCuNb16-4 ESR Wrought billets or round bars, for subsequent cold cutting and hot forging into turbine blades

Keywords: X5CrNiCuNb16-4, X5CrNiCuNb17-4, AISI 630, 17-4 PH, S17400, 1.4542

Metallurgy: EAF, followed by AOD or VOD, followed by ESR

Process route and surface finish: Hot forged or rolled, overaged, descaled or rough machined (1E or 1X according to UNI EN 10088-3)

Applicable standards: UNI EN 10088-3, UNI EN ISO 6506, ASTM E112, SAE AMS 2315, ASTM E45, ASTM E381, UNI EN ISO 6892, UNI EN ISO 148, ASTM A 370, SEP 1923.

Material Properties Requirements:

Chemical Composition:

    All the values are given in weight percentage [%]. Wherever not specified, no alloying addition should be made. * = Value of N to be reported in a separate sheet.

Microstructure

• The microstructure shall be uniform and fine grained across the whole product section.
• Chemical segregations resulting in linear indications, segregated bands, big size carbides (Ø ≥ 10 μm), carbides allignments, carbides precipitations at former austenitic grain boundaries shall not be accepted.
• Avg. grain size according to ASTM E112: ≥ 5.
• Fields with avg. grain size according to ASTM E112 < 3 shall not be accepted.
• Delta ferrite content according to SAE AMS 2315 < 0.9% on the worst field.
• Inclusions content according to ASTM E45, Method A:

• A		B		C		D
  Thin	Heavy	Thin	Heavy	Thin	Heavy	Thin	Heavy
  1	0.5	1	0.5	1	0.5	1	0.5

Expected mechanical properties

• Rp 0.2 % [MPa]	Rm % [MPa]	A5 [%]	Z [%]	Impact Energy [J]	Hardness [HB]	FATT50 [°C] (**)
  930-1000	max 1040	min 13%	min 50%	min 100(*)	295-335	max -25°C

(*) = Avg of 3 specimens

(**) = meaning at least 50% shear below the indicated temperature. Shear percentage to be evaluated according to ASTM A 370. The FATT50 diagram shall be included in the certificate, the choice of points shall allow a consistent fitting, for example temperatures should lay over a span of 60 degrees, centered on the target value.