Grade 3

Datasheet
ASTM Grade (UNS No.)GRADE 3 (R50550)
Chemical Composition (Max. values unless range is shown)(wt. %)0.08C 0.05N 0.35O 0.30Fe 0.015H
TENSILE PROPERTIESGuar.R.T. Min.Typical Elevated Temperature Properties
93˚C (200˚F)204˚C (400˚F)315˚C (600˚F)426˚C (800˚F)
Ultimate StrengthMPa (ksi)448 (65)469 (68)310 (45)262 (38)207 (30)
Yield Strength, 0.2% offsetMPa (ksi)379 (55)338 (49)207 (30)138 (20)117 (17)
Elongation in 51 mm (2″) gage length(%)1824353322
Reduction in Area – Bar, Billet & Forging only(%)30
OTHER MECHANICAL PROPERTIES
Stress to Rupture in Time ShownStressMPa (ksi)400 (58)300 (43)228 (33)138 (20)
Time-Hrs. at Temp. (˚C)1,000 (25)10,000 (100)10,000 (200)1,000 (250)
Stress &Time to Produce Elongation Shown (creep)StressMPa (ksi)283 (41)241 (35)83 (12)131 (19)
Time-Hrs. at Temp. (˚C)100 (25)1,000 (25)1,000 (315)1,000 (250)
Creep(%)1111
Charpy V-Notch Impact @ R.T.Joules (ft-lbs)24 – 48 (18 – 35)
Bend RadiusUnder 1.78 mm (0.070″) thick2.0 – 2.5 x Thickness
1.78 mm (0.070″) and over2.5 x Thickness
Welded Bend Radius2.5 – 3.0 x Thickness
Nominal Hardness90 HRB
PHYSICAL PROPERTIES
Nominal Beta Transus°C (°F)920 (1690)
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)43 (6.2)
Thermal ConductivityW/m•˚C (BTU/hr•ft•˚F)19.7 (11.4)
Specific HeatJ/Kg•˚C (BTU/lb•˚F)520 (0.124)
WeldabilityExcellent
Industry SpecificationsASTM – B265, B337, B338, B348, B363, B381,B861, B862, F67; and AMS 4900