Grade 7

Datasheet
ASTM Grade (UNS No.)GRADE 7 (R52400)
Chemical Composition (Max. values unless range is shown)(wt. %)0.08C; 0.03N; 0.25O; 0.30Fe; 0.12-0.25Pd; 0.015H
TENSILE PROPERTIESGuar.R.T. Min.Typical Elevated Temperature Properties
93˚C (200˚F)204˚C (400˚F)315˚C (600˚F)
Ultimate StrengthMPa (ksi)345 (50)393 (57)283 (41)221 (32)
Yield Strength, 0.2% offsetMPa (ksi)276 (40)276 (40)166 (24)103 (15)
Elongation in 51 mm (2″) gage length(%)20284138
Reduction in Area – Bar, Billet & Forging only(%)30405575
OTHER MECHANICAL PROPERTIES
Stress to Rupture in Time ShownStressMPa (ksi)276 (40)240 (35)117 (17)
Time-Hrs. at Temp. (˚C)10,000 (100)10,000 (150)1,000 (250)
Stress &Time to Produce Elongation Shown (creep)StressMPa (ksi)209 (30)179 (26)103 (15)
Time-Hrs. at Temp. (˚C)1,000 (25)1,000 (150)1,000 (250)
Creep(%)1.01.01.0
Charpy V-Notch Impact @ R.T.Joules (ft-lbs)40 – 82 (30 – 60)
Bend RadiusUnder 1.78 mm (0.070″) thick2.0 x thickness
1.78 mm (0.070″) and over2.5 x Thickness
Welded Bend Radius2.5-3.0 x Thickness 70 HRB
Nominal Hardness82 HRB
PHYSICAL PROPERTIES
Nominal Beta Transus°C (°F)913 (1675)
Coefficient of Thermal Expansion 10-6/˚C (10-6/˚F)0-100˚C (32 -212˚F)8.6(4.8)
0-315˚C (32-600˚F)9.2(5.1)
0-538˚C (32-1000˚F)9.7(5.4)
0-648˚C (32-1200˚F)10.1(5.6)
0-816˚C (32-1500˚F)10.1(5.6)
Densityg/cm3 (lbs/in3)4.51(0.163)
Melting Point, Approx.°C (°F)1660 (3020)
Electrical Resistivity @ R.T.10-6 ohm•cm (10-6 ohm•in)56 (22)
Modulus of Elasticity – TensionGPa (103 ksi)103 (15)
Modulus of Elasticity – TorsionGPa (103 ksi)41 (6.0)
Thermal ConductivityW/m•˚C (BTU/hr•ft•˚F)20.8 (12.0)
Specific HeatJ/Kg•˚C (BTU/lb•˚F)520 (0.124)
WeldabilityExcellent
Industry SpecificationsASTM – B265, B337, B338, B348, B363, B381, B861 and B862