High alloy steel, 280 (300) Maraging Steel, Maraged at 482°C (900°F)
Condition
Maraged at 480°C
UNS number
K93120, ~J93150 (cast)
US name
AMS 6521
EN number
1.6354, 1.6358
Maraging steel 300 Typical uses
Missile casings, aircraft forgings, structural components, cannon recoil and Belleville springs, bearings, transmission and fan shafts for commercial jet engines, couplings, hydraulic hoses, bolts, punches, and tooling dies.
Maraging steel 300 Composition detail
Al (aluminum)
0.05
–
0.15
%
C (carbon)
0
–
0.03
%
Co (cobalt)
8.5
–
9.5
%
Fe (iron)
65.1
–
68.4
%
Mn (manganese)
0
–
0.1
%
Mo (molybdenum)
4.6
–
5.2
%
Ni (nickel)
18
–
19
%
P (phosphorus)
0
–
0.01
%
S (sulfur)
0
–
0.01
%
Si (silicon)
0
–
0.1
%
Ti (titanium)
0.5
–
0.8
%
Maraging steel 300 Physical properties
Density
7.88
–
7.96
g/cm3
Maraging steel 300 Mechanical properties
Young’s modulus
183
–
192
GPa
Specific stiffness
23.1
–
24.3
MN.m/kg
Yield strength (elastic limit)
1810
–
2000
MPa
Tensile strength
1870
–
2070
MPa
Specific strength
228
–
252
kN.m/kg
Elongation
4
–
5
% strain
Compressive strength
1710
–
1940
MPa
Flexural modulus
183
–
192
GPa
Flexural strength (modulus of rupture)
1810
–
2000
MPa
Shear modulus
70
–
73.6
GPa
Bulk modulus
160
–
169
GPa
Poisson’s ratio
0.31
–
0.323
Shape factor
11
Hardness – Vickers
515
–
550
HV
Elastic stored energy (springs)
8690
–
10600
kJ/m3
Fatigue strength at 10^7 cycles
816
–
897
MPa
Fatigue strength model (stress range) Parameters: Stress Ratio = -1, Number of Cycles = 1e7cycles
768
–
953
MPa
Maraging steel 300 Impact & fracture properties
Fracture toughness
75
–
85
MPa.m0.5
Toughness (G)
30
–
38.4
kJ/m2
Maraging steel 300 Thermal properties
Melting point
1430
–
1450
°C
Maximum service temperature
460
–
490
°C
Minimum service temperature
-73
–
-53
°C
Thermal conductivity
25.1
–
27.2
W/m.°C
Specific heat capacity
377
–
392
J/kg.°C
Thermal expansion coefficient
9.9
–
10.4
µstrain/°C
Thermal shock resistance
938
–
1060
°C
Thermal distortion resistance
2.46
–
2.7
MW/m
Latent heat of fusion
202
–
283
kJ/kg
Maraging steel 300 Electrical properties
Electrical resistivity
36
–
70
µohm.cm
Electrical conductivity
2.46
–
4.79
%IACS
Galvanic potential
-0.47
–
-0.39
V
Maraging steel 300 Magnetic properties
Magnetic type
Magnetic
Maraging steel 300 Optical, aesthetic and acoustic properties
Transparency
Opaque
Acoustic velocity
4810
–
4930
m/s
Mechanical loss coefficient (tan delta)
2.2e-4
–
0.0012
Maraging steel 300 Processing properties
Metal casting
Unsuitable
Metal cold forming
Excellent
Metal hot forming
Excellent
Metal press forming
Acceptable
Metal deep drawing
Limited use
Machining speed
3.05 m/min
Weldability Notes: Preheating may be required, post weld heat treatment is required
Good
Carbon equivalency
0.607 – 0.7
Maraging steel 300 Durability
Water (fresh)
Acceptable
Water (salt)
Limited use
Weak acids
Limited use
Strong acids
Unacceptable
Weak alkalis
Acceptable
Strong alkalis
Limited use
Organic solvents
Excellent
Oxidation at 500C
Acceptable
UV radiation (sunlight)
Excellent
Galling resistance (adhesive wear)
Acceptable
Flammability
Non-flammable
Maraging steel 300 Corrosion resistance of metals
Stress corrosion cracking Note: Rated in chloride; Other susceptible environments: Potassium dichromate
Slightly susceptible
Maraging steel 300 Standards with similar compositions
Germany: 1.6358 to DIN
USA: 73 to ASTM A579, Grade 20 to ASTM A646-95, UNS K93120, UNS K93120 to UNS, UNS K93130, UNS K93130 to UNS
Tradenames: BOHLER W720, CARPENTER NIMARK 300, JESSOP-SAVILLE G 125 D V, KRUPP HFX 6358, KRUPP WL 1.6354, LESCALLOY MARVAC 300, NIMAR 700, NIMARK ALLOY 300, PRP MARAGING 300, USS MARAGING STEEL GR. 300, VAR STEEL GR. 280, VASCOMAX 300, VASCOMAX 300 W, VM, VASCOMAX 350
