AISI 422, SUH 616, B50A951, 1.4935, X20CrMoWV12-1

AISI 422, also known as Alloy 616, 1.4935, and X20CrMoWV12-1, represents a class of high-alloy, creep-resistant martensitic stainless steels engineered for demanding high-temperature applications. These steels, characterized by a 12% chromium content, offer superior corrosion resistance compared to standard steels, making them ideal for critical thermal engine components in power generation facilities

AISI 422, SUH 616, B50A951, 1.4935, X20CrMoWV12-1
AISI 422, SUH 616, B50A951, 1.4935, X20CrMoWV12-1
AISI 422, SUH 616, B50A951, 1.4935, X20CrMoWV12-1
AISI 422, SUH 616, B50A951, 1.4935, X20CrMoWV12-1

What is AISI 422, SUH 616, B50A951, 1.4935, X20CrMoWV12-1?

AISI 422, also known as Alloy 616, 1.4935, and X20CrMoWV12-1, represents a class of high-alloy, creep-resistant martensitic stainless steels engineered for demanding high-temperature applications. These steels, characterized by a 12% chromium content, offer superior corrosion resistance compared to standard steels, making them ideal for critical thermal engine components in power generation facilities.

These materials are specified under a range of international standards, including B50A951 (A1, A2), SIEMENS 10705 (BL/M, BR, BU), ASME SA-437 Grade B4B, ASTM A437 Grade B4B, ASTM A565 Grade 616, JIS G4311 SUH 616, and SAE J 775 SUH 616. Specifically, ASME SA-437 and ASTM A437 Grade B4B designate alloy steel turbine-type bolting materials that have undergone specialized heat treatment for high-temperature service. ASTM A565 Grade 616 focuses on martensitic stainless steel bars for high-temperature applications. JIS G4311 SUH 616 and SAE J 775 SUH 616 pertain to heat-resisting steel bars, wire rods, and engine poppet valve information, respectively, highlighting the versatility of these alloys across diverse engineering needs.

Manufacturer OEM Part Numbers
Franco Tosi 1.12.KA.801.58.KA.80
Siemens 10705BL/M10705BR10705BU
GE B50A951A1, A2
Nuovo Pignone ITN 02123/AITN 07760ITN 07763.09
Ansaldo TSM0706

Applications

Primarily utilized in the fabrication of turbine blades, steam turbine buckets, high-temperature bolting fasteners, valves, and various other miscellaneous components, these alloys are designed to withstand continuous operating temperatures up to 580°C. Their chrome-nickel matrix, featuring an austenitic structure with dispersed carbides, is further enhanced by alloying additions of molybdenum, vanadium, and tungsten. These elements elevate the melting temperature, significantly improving creep resistance and ensuring structural integrity under prolonged thermal stress.

Chemical Composition (%)

Grade Chemical composition WT %
C Si Mn P S Cr Mo Ni V W Cu Sn Al Co Ti

Ge Power B50A951 A1

 0.20-0.25 0.20-0.50 0.50-1.00 Max 0.025 Max 0.015 11.00-12.50 0.90-1.25 0.50-1.00 0.20-0.30 0.90-1.25 Max 0.15 Max 0.02 Max 0.025 0.20 0.025

Ge Power B50A951 A2

 0.20-0.25 0.20-0.50 0.50-1.00 Max 0.020 Max 0.010 11.00-12.50 0.90-1.25 0.50-1.00 0.20-0.30 0.90-1.25 Max 0.15 Max 0.02 Max 0.025 0.20 -

Ge Power B50A249 S12

 0.20-0.25 0.20-0.50 0.50-0.90 0.025 0.025 11-12.50 0.9-1.25 0.5-1.0 0.2-0.3 0.9-1.25
 - 0.02
 0.025 0.20 0.05

ASME B4B, ASTM Grade B4B

 0.20-0.25 0.20-0.50 0.50-1.00 Max 0.025 Max 0.025 11.00-12.50 0.90-1.25 0.50-1.00 0.20-0.30 0.90-1.25 - Max 0.04 Max 0.05 Max 0.050

ASTM A565 616

 0.20-0.25 Max 0.50 0.50-1.00 Max 0.025 Max 0.025 11.00-12.50 0.90-1.25 0.50-1.00 0.20-0.30 0.90-1.25 - - - - -

EN 1.4935, X20CrMoWV12-1

 0.17-0.24 0.10-0.50 0.30-0.80 Max 0.025 Max 0.015 11.0-12.5 0.80-1.20 0.3-0.8 0.25-0.35 0.4-0.6 -

JIS SUH 616

 0.20-0.25 Max 0.50 0.50-1.00 Max 0.040 Max 0.03 11.0-13.0 0.75-1.25 0.5-1.0 0.2-0.3 0.75-1.25 Max 0.3

AISI 422, S42200

 0.20-0.25 Max 0.75 Max 1.00 Max 0.040 Max 0.03 11.0-12.5 0.75-1.25 0.5-1.0 0.15-0.30 0.75-1.25 Max 0.5

Material Properties

Type 422 Mechanical properties acc. to GE B50A951

    Type 422 Class A1, A2, A4

    • Tensile strength KSI(MPa): Min 140(965)
    • Yield Strength 0.02%, Offset KSI(MPa): Min 90(620) *
    • Elong. In 2": Min 13 %
    • RA: Min 35%
    • Brinell Hardness, 3000Kg laod: 285-331
    • Kv, Min at  R.T.  ft-lb(J): 10(13.36)

    Type 422 Class A3

    • Tensile strength KSI(MPa): Min 110(759)
    • Yield Strength 0.02%, Offset KSI(MPa): Min 80(555) *
    • Elong. In 2": Min 18 %
    • RA: Min 50%
    • Brinell Hardness, 3000Kg laod: 223-269
    • Kv, Min at  R.T.  ft-lb(J): 25(33.90)

Tensile Requirements (B50A249B Only)

  • Tensile Strength, psi, min. 140,000
  • Yield Strength, psi, 0.02%, min. 90,000
  • Elongation, % in 2 inches, min. 12
  • Reduction of Area, %, min. 25
  • Charpy V-Notch Impact Energy Requirements (B50A249B Only)

    • Two Charpy V-Notch Impact energy tests shall be conducted at room temperature (70F +/-10F) and have following properties:

    Standard Charpy V-Notch Impact, ft-lb, min. 10

  • Hardness Requirements

    • Two Brinell Hardness measurements shall be taken at the 0-degree and 180 Degree locations on one end and at the 90-degree and 270-degree locations on the opposite end of each forging. The measurements shall be taken at each end, on either the end face or a radial face in close proximity to the end. All measurements must meet the following requirements:

    Brinell Hardness Number, 3000 kg load 290-332

Stress Rupture Requirements (B50A249B Only)

Smooth bar stress rupture tests shall be conducted on each forging or each heat treated forging length. The test may be discontinued after the minimum requirement for time to rupture has been exceeded. The test must meet the following requirements:

  • Temperature (Degree F): 1200
  • Stress (psi): 26,000
  • Min. Time to Rupture (hrs.): 25

1.4935 Mechanical properties acc. to EN 10302

  • +QT700
    • Tensile strength KSI(MPa): 700 to 850
    • Yield Strength 0.02%, Offset KSI(MPa): Min 500
    • A5 15%
  • +QT800
    • Tensile strength KSI(MPa): 800 to 950
    • Yield Strength 0.02%, Offset KSI(MPa): Min 600
    • A5 14%

Grade B4B Stress Rupture

  • Test Method: ASTM E139
  • Temperature: 650 °C
  • Load:200 MPa
  • Result: Life = 25 hours,Elongation and Reduction of Area = For information On bar having lowest hardness for each heat lot.

1.4935 QT700 Creep

temperature,(℃) Time,(h) 1% Rp1(MPa) 0.5% Rp0.5(MPa) 0.2% Rp0.2(MPa) 0.1% Rp0.1(MPa) CRS(MPa)
470 10000.0h 324.0 - - - 368.0
470 100000.0h 260.0 - - - 309.0
470 200000.0h - - - - 285.0
480 10000.0h 299.0 - - - 345.0
480 100000.0h 236.0 - - - 284.0
480 200000.0h - - - - 262.0
490 10000.0h 269.0 - - - 319.0
490 100000.0h 213.0 - - - 260.0
490 200000.0h - - - - 237.0
500 10000.0h 247.0 - - - 294.0
500 100000.0h 190.0 - - - 235.0
500 200000.0h - - - - 215.0
510 10000.0h 227.0 - - - 274.0
510 100000.0h 169.0 - - - 211.0
510 200000.0h - - - - 191.0
520 10000.0h 207.0 - - - 253.0
520 100000.0h 147.0 - - - 186.0
520 200000.0h - - - - 167.0
530 10000.0h 187.0 - - - 232.0
530 100000.0h 130.0 - - - 167.0
530 200000.0h - - - - 147.0
540 10000.0h 170.0 - - - 213.0
540 100000.0h 114.0 - - - 147.0
540 200000.0h - - - - 128.0
550 10000.0h 151.0 - - - 192.0
550 100000.0h 98.0 - - - 128.0
550 200000.0h - - - - 111.0
560 10000.0h 135.0 - - - 173.0
560 100000.0h 85.0 - - - 112.0
560 200000.0h - - - - 96.0
570 10000.0h 118.0 - - - 154.0
570 100000.0h 72.0 - - - 96.0
570 200000.0h - - - - 81.0
580 10000.0h 103.0 - - - 136.0
580 100000.0h 61.0 - - - 82.0
580 200000.0h - - - - 68.0
590 10000.0h 90.0 - - - 119.0
590 100000.0h 52.0 - - - 70.0
590 200000.0h - - - - 58.0
600 10000.0h 75.0 - - - 101.0
600 100000.0h 43.0 - - - 59.0
600 200000.0h - - - - 48.0
610 10000.0h 64.0 - - - 87.0
610 100000.0h 36.0 - - - 50.0
610 200000.0h - - - - 40.0
620 10000.0h 53.0 - - - 73.0
620 100000.0h 30.0 - - - 42.0
620 200000.0h - - - - 33.0
630 10000.0h 44.0 - - - 60.0
630 100000.0h 25.0 - - - 34.0
630 200000.0h - - - - 27.0
640 10000.0h 36.0 - - - 49.0
640 100000.0h 20.0 - - - 28.0
640 200000.0h - - - - 22.0
650 10000.0h 29.0 - - - 40.0
650 100000.0h 17.0 - - - 23.0
650 200000.0h - - - - 18.0

High Temperature acc. to EN 10302

High Temperature - +QT700

  • Temp 50 °C - > 465 MPa
  • Temp 100 °C - > 460 MPa
  • Temp 150 °C - > 445 MPa
  • Temp 200 °C - > 430 MPa
  • Temp 250 °C - > 415 MPa
  • Temp 300 °C - > 390 MPa
  • Temp 350 °C - > 380 MPa
  • Temp 400 °C - > 360 MPa
  • Temp 450 °C - > 330 MPa
  • Temp 500 °C - > 290 MPa
  • Temp 550 °C - > 250 MPa

High Temperature - +QT800

  • Temp 50 °C - > 585 MPa
  • Temp100 °C - > 560 MPa
  • Temp 150 °C - > 545 MPa
  • Temp 200 °C - > 530 MPa
  • Temp 250 °C - > 505 MPa
  • Temp 300 °C - > 480 MPa
  • Temp 350 °C - > 450 MPa
  • Temp 400 °C - > 420 MPa
  • Temp 450 °C - > 380 MPa
  • Temp 500 °C - > 335 MPa
  • Temp 550 °C - > 280 MPa

Physical Properties

  • Density: 7.7 g/cm3
  • Linear expansion coefficient: 10.5-12.5 *10-6m/(m*K)
  • Thermal conductivity: 24 W/(m*K)
  • Specific heat capacity: 460 J/(kg*K)
  • Young's modulus: 216 GPa
  • Electrical resistivity: 0.6 µΩ*m
  • Tensile strength Rm: > 600 MPa
  • Creep limit for max elongation 0.2% Rp0.2: Min 800 MPa
  • Creep-rupture strength Ru: Min 275 MPa; 500°C; 100000h

Heat Treatment

Heat treatment for 1.4935

  • Quenching: 1020-1070 °C
  • Tempering: 680-780 °C

Heat treatment for B50A249 S12

  • Austenitization (All Classes)

    • Forging shall be heated slowly to 1875oF- 1925oF and held at temperature approximately 30 minutes per inch of thickness or diameter, to assure uniform temperature within the load and each part thereof.

  • Quenching
    • B5QA249B

      • Each forging shall be oil quenched to a temperature below 600F. The forging shall then be cooled to a temperature below the Mf temperature (approximately 300F) to assure complete transformation. GE Test Method E50A209 is to be used as a guide for selecting adequate quenching times. Time of immersion in oil, and the maximum surface temperature of the forging during the first ten minutes after removal from the oil shall be reported.

    • B50A249C

      • Forging shall be forced air quenched to a temperature below the Mf temperature (approximately 300F) to assure complete transformation.

  • Tempering (All Classes)

    • Forging shall be double tempered. The first temper shall be at 110OF minimum. The second temper shall be at 11 50F minimum. The forging shall be held at the temperature for one (1) hour per inch of maximum thickness or diameter during the tempering cycle and then cooled uniformly to room temperature.

  • Stress Relief Anneal (SRA)

    • When a stress relief heat treatment is performed, the forging shall be stress relieved at a temperature 50F below the final tempering temperature and shall be still air or furnace cooled.

Austenitization-Material shall be heat treatedto1875-1925F and held at temperature for a sufficient time to assure uniform temperature within the load and each part thereof.

Quenching -Material shall be quenched to a temperature below 600℉ and then cooled to a temperature below theM(approximately 150℉) to assure complete transformation.

B50A951 A1-Material shall be oil quenched.Use of air quenching is prohibited.

B50A951 A2, A3, A4-Material shall be quenched in oil or rapidly moving air.

Tempering-Material shall be uniformly heated to the tempering temperature of 1150F° minimum.

Processing Performance

Welding

welding of this material is not straightfor- ward owing to its crack sensitivity.

Inventory
Total weight: 0 Kg
Inventory Update Date:
Grade
Size (mm)
Shape
Weight (kg)
Cond.
Melting
No inventory data available