DZ438G

HuaNickel DZ438G is a nickel-based precipitation-hardening directional solidified column-crystal superalloy, which is developed on the basis of K438G alloy. Compared with K438G alloy, the operating temperature of this alloy is about 45°C higher, and the thermal strength is higher, and the structure is more stable. The alloy also has excellent thermal corrosion resistance, and is suitable for making turbine blades and other high-temperature components working in a hot corrosion environment below 900 °C, especially for making gas turbine blades that operate for a long time under ocean atmosphere conditions.

DZ438Gchemical composition：

	Fe	C	Cr	Co	W	Mo	AI	Ti	Nb	Ta	Fe	S	Mn	Si	Sn
Min	Bal	0.08	15.5	8	2.4	1.5	3.5	3.5	0.4	1.5	≤
Max		0.14	16.4	9	2.8	2	4.3	4.3	1	2	0.3	0.15	0.15	0.15	0.002

DZ438GPhysical properties：

Density	8.1g/cm³
Melting point	1242℃~1332℃
Magnetic properties	not

Coefficient of linear expansion

θ/℃	20～100	20～200	20～300	20～400	20～500
α/(10-6℃-1)	10.82	11.95	12.42	13.09	13.09
θ/℃	20～600	20～700	20～800	20～900
α/(10-*℃-I)	13.64	13.64	13.84	14.50

Resilient performance

θ/℃	20	100	200	300	400	500
Ed/GPa	118	114	111	108	106	103
θ/℃	600	700	800	900	1000
Ed/GPa	100	95	91	85	75

DZ438GMechanical properties：

Standard number	variety	Sampling	heat treatment	θ/℃	Long-lasting performance		Tensile properties
					σ/MPa	τ/h	σb/MPa	δ₅/%	ψ/%
GJB 5512.2 SGDZ 38G	Master alloy	DirectionalsolidificationeststicksLongitudinal	standard  heat treatment	700	784	≥100	—	一	—
				800	422	≥60	≥784	≥8.0	≥10.0

DZ438GAlloy properties：

The surface of DZ438G alloy parts needs to be coated with Al Si to further improve the hot corrosion resistance of the alloy. After the alloy is aged at 850°C × 500h for a long time, the notσ brittle phase is precipitated.

DZ438GUses of alloys：

HuaNickel DZ438G alloy blades have passed the long-term bench test on the ship gas generator, as well as the test qualification under various working conditions, and the promotion and application prospects are great

DZ438GApplication field process performance：

Parts heat treatment: Standard heat treatment system of alloys. Parts should be laid flat in bulk in a single layer during heating and cooling to avoid deformation. The heat treatment process is as follows: 700°C furnace loading, 200°C/h speed to the specified temperature.

Relevant standards：

GB/T14992 、GJB5512.2  、SGDZ  38G