GTD 450, B50A789


B50A789(GTD 450) Cr-Ni-Cu-Nb-Cb-Fe Alloy, stainless steel is a common material for manufacturing gas turbine compressor blades and guide vanes. From the perspective of composition characteristics, B50A789 steel is similar to alloy structural steel(0Cr17Ni4Cu4Nb), and both belong to precipitation hardening martensitic stainless steel 1, and its strengthening mechanism mainly relies on aging strengthening of copper-rich phase and precipitation strengthening of molybdenum and niobium. The Charpy impact test method is one of the important means to test the mechanical properties of materials, and is widely used to evaluate the ductile-brittle properties of B50A789 steel under impact loads.

GTD 450, B50A789 - Introduction and Application

B50A789(GTD 450) steel is a common material for manufacturing gas turbine compressor blades and guide vanes. From the perspective of composition characteristics, B50A789 steel is similar to alloy structural steel(0Cr17Ni4Cu4Nb), and both belong to precipitation hardening martensitic stainless steel 1, and its strengthening mechanism mainly relies on aging strengthening of copper-rich phase and precipitation strengthening of molybdenum and niobium. The Charpy impact test method is one of the important means to test the mechanical properties of materials, and is widely used to evaluate the ductile-brittle properties of B50A789 steel under impact loads.

B50A789 Class A, B, E, F, H, B50A789 Class G the composition and performance introduction.


Melted process

  • AOD+ESR

GTD 450, B50A789 - Chemical composition WT %

GradeChemical Composition WT %
CMnSiPSCrCuNiMoNb
GTD 450≤0.05≤1.00≤1.00≤0.03≤0.0314.0-16.01.25-1.755-70.5-1.00.35-0.75
Alloy 450≤0.05≤1.00≤1.00≤0.03≤0.0314.0-16.01.25-1.755-70.5-1.00.35-0.75
UNS S45000≤0.05≤1.00≤1.00≤0.03≤0.0314.0-16.01.25-1.755-70.5-1.0Nb >8 x (%C)
XM-25≤0.05≤1.00≤1.00≤0.03≤0.0314.0-16.0
1.25-1.755-70.5-1.0Nb >8 x (%C)
ASTM A564≤0.05≤1.00≤1.00≤0.03≤0.0314.0-16.0
1.25-1.755-70.5-1.0Nb >8 x (%C)
X 5 CrNiMoCuNb 14 5≤0.07≤1.00≤0.70≤0.04≤0.01513.0-15.01.20-2.005.0-6.01.20-2.000.15-0.60
1.4594≤0.07≤1.00≤0.70≤0.04≤0.01513.0-15.01.20-2.005.0-6.01.20-2.000.15-0.60

Mechanical Property of GTD 450, B50A789

PropertiesMetricImperial
Tensile strength986 MPa143000 psi
Yield strength (@ strain 0.200%)814 MPa118000 psi
Bulk modulus (typical for steel)166 GPa24100 ksi
Shear modulus (typical for steel)83.9 GPa12200 ksi
Charpy impact125 - 141 J92.2 - 104 ft-lb
Elongation at break (gage length is 4 times specimen diameter)13.30%13.30%
Hardness, Brinell (converted from Rockwell C hardness)278278
Hardness, Knoop (converted from Rockwell C hardness)296296
Hardness, Rockwell C2828
Hardness, Vickers (converted from Rockwell C hardness)287287

Physical Property of GTD 450, B50A789

PropertiesMetricImperial
Density7.80 cm³0.282 lb/in³

Heat Treatment of GTD 450, B50A789

Hot Working

GTD 450, XM-25, S45000, 450 Alloy stainless steel alloy can be hot worked by soaking at 1150-1177°C (2100-2150°F) followed by cooling and fully annealing.

Cold Working

Custom 450, XM-25, S45000, 450 Alloy stainless steel alloy can be cold worked using all common techniques.


Annealing

Custom 450, XM-25, S45000, 450 Alloy stainless steel alloy is annealed by soaking at 1024-1052°C (1875-7925°F) for 1 h followed by quenching in water or oil.


Aging

Custom 450, XM-25, S45000, 450 Alloy stainless steel alloy is soaked at specific temperature for 4 h followed by cooling to obtain condition H900, H950, H1000, H1050 or H1150.



Welding of GTD 450, B50A789

GTD 450, XM-25, S45000, 450 Alloy stainless steel alloy can be welded using shielded methods to reduce contamination.


Machining of GTD 450, B50A789

GTD 450, XM-25, S45000, 450 Alloy stainless steel alloy uses feeds and speeds comparable with other martensitic stainless steels. It is preferred to use positive feeds and slow speeds to achieve good results.


Equivalent grades of GTD 450, B50A789

Custom 450, XM-25, S45000, 450 Alloy, 1.4594, X5CrNiCuMo15-06, X 5 CrNiMoCuNb 14 5,  B50A789, MAT 238863

GTD 450, B50A789 Martensitic & Precipitation hardened stainless steel stock list

Grade Shape Dimensionmm Qty.kg
C450 Round bar Φ120 x 1170 415
Alloy 450 Round bar Φ100 x 1000 650
UNS S45000 Round bar Φ55 x 1000 498
Custom 450 Round bar Φ50 x 1600 398
B50A789 Round bar Φ55 x 2000 1123