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 PROPERTIES Guar.R.T. Min. Typical Elevated Temperature Properties
93˚C (200˚F) 204˚C (400˚F) 315˚C (600˚F) 426˚C (800˚F)
Ultimate Strength MPa (ksi) 448 (65) 469 (68) 310 (45) 262 (38) 207 (30)
Yield Strength, 0.2% offset MPa (ksi) 379 (55) 338 (49) 207 (30) 138 (20) 117 (17)
Elongation in 51 mm (2″) gage length (%) 18 24 35 33 22
Reduction in Area – Bar, Billet & Forging only (%) 30
OTHER MECHANICAL PROPERTIES
Stress to Rupture in Time Shown Stress MPa (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) Stress MPa (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 (%) 1 1 1 1
Charpy V-Notch Impact @ R.T. Joules (ft-lbs) 24 – 48 (18 – 35)
Bend Radius Under 1.78 mm (0.070″) thick 2.0 – 2.5 x Thickness
1.78 mm (0.070″) and over 2.5 x Thickness
Welded Bend Radius 2.5 – 3.0 x Thickness
Nominal Hardness 90 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)
Density g/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 – Tension GPa (103 ksi) 103 (15)
Modulus of Elasticity – Torsion GPa (103 ksi) 43 (6.2)
Thermal Conductivity W/m•˚C (BTU/hr•ft•˚F) 19.7 (11.4)
Specific Heat J/Kg•˚C (BTU/lb•˚F) 520 (0.124)
Weldability Excellent
Industry Specifications ASTM – B265, B337, B338, B348, B363, B381,B861, B862, F67; and AMS 4900