446 / UNS S44600 (EN 1.4762, X10CrAl24) is a high-chromium ferritic heat-resistant stainless steel bar engineered for sustained oxidation resistance up to 1,150 degC. Its 23-27% Cr content, reinforced by aluminum addition, forms a dense, adherent Cr2O3-Al2O3 protective scale that resists spalling under severe thermal cycling and sulfur-bearing atmospheres found in refinery and petrochemical furnace environments. SHUNFU METAL produces 446 bars through EAF + AOD + LF + VD melting, with optional ESR refining to minimize non-metallic inclusions. All heats are fully traceable and conform to our ISO 9001 and API Q1 certified quality system.
Equivalent Grades of 446 / S44600
Standard
Designation
ASTM A276 / A240
446 / UNS S44600
EN 10088-3 / EN 10095
1.4762 X10CrAl24
DIN
X10CrAlSi25 / 1.4762
JIS G4311
SUH446
GOST
10X24A / 15X28
GB/T 20878
2Cr25N / 16Cr25N
446 Stainless Steel Bar
SHUNFU METAL
Oil & Gas and High-Temperature Applications
Refinery Furnace Tubes
Radiant and convection section tubes in crude oil heaters, reformer furnaces, and cracking furnaces exposed to sulfur-rich flue gas.
Burner Nozzles & Combustion Parts
Gas burner tips, flame stabilizers, and combustion chamber liners in process heaters and thermal oxidizers.
Soot Blower Components
Lance tubes and nozzle heads for soot blowers in refinery utility boilers and FCC regenerator flue gas systems.
Thermocouple Protection Tubes
Protection sheaths for temperature sensors in high-temperature reactors, reformers, and sulfur recovery units.
Heat Treat Baskets & Fixtures
Annealing boxes, retorts, muffle liners, and charge baskets for heat treatment operations in pipe mill and fitting shops.
Furnace Hardware & Supports
Tube supports, hangers, grate bars, and walking beam rails in petrochemical reheat and heat-treatment furnaces.
Supply Range
Hot Rolled Round Bar
Diameter
10 mm – 300 mm
Length
3,000 – 6,000 mm
Hot Rolled Flat Bar
Thickness x Width
10 mm – 100 mm x 20 mm – 500 mm
Length
2,000 – 6,000 mm
Forged Round Bar
Diameter
80 mm – 800 mm
Length
2,000 – 8,000 mm
Forged Flat / Block
Thickness x Width
40 mm – 400 mm x 100 mm – 1,000 mm
Length
1,500 – 6,000 mm
Delivery condition: annealed at 780-880 degC (air cool). As 446 is a ferritic grade, it does not respond to hardening by heat treatment; all mechanical properties are achieved through controlled annealing. SHUNFU METAL produces bars using a 6,000-ton forging press and radial forging machine with full ISO 9001 and API Q1 traceability.
Chemical Composition
Element
ASTM A276 S44600
EN 10088-3 1.4762
SHUNFU METAL Internal
C
leq 0.20
leq 0.12
leq 0.10
Cr
23.0 – 27.0
23.0 – 26.0
24.0 – 26.0
Al
1.0 – 2.0
1.2 – 2.2
1.3 – 1.8
Si
leq 1.00
0.70 – 1.40
0.80 – 1.20
Mn
leq 1.50
leq 1.00
leq 0.80
Ni
leq 0.60
leq 0.50
leq 0.40
P
leq 0.040
leq 0.040
leq 0.025
S
leq 0.030
leq 0.015
leq 0.010
SHUNFU METAL applies tight controls on Al (1.3-1.8%) to ensure a stable Cr2O3-Al2O3 duplex oxide layer that resists spalling under cyclic heating. All heats undergo AOD refining for precise carbon deoxidation, followed by OES and LECO analysis per ISO 9001 and API Q1 protocols.
Mechanical & High-Temperature Properties
Property (Annealed, Room Temp)
Value
Tensile Strength, Rm
520 – 720 MPa
Yield Strength, Rp0.2
geq 280 MPa
Elongation, A5
geq 10% (longitudinal)
Hardness
leq 223 HB
Density
7.7 g/cm3
Max Service Temp (Air)
1,150 degC
Elevated-Temp Creep Rupture Strength
Temp
10,000 h (MPa)
500 degC
~100
600 degC
~35
700 degC
~9.5
800 degC
~4.3
900 degC
~1.9
Heat treatment: anneal at 780-880 degC, hold for 1-2 h per 25 mm of section, air cool or water quench. This grade is ferritic and does not harden via martensitic transformation. Stress relieving at 600-700 degC is recommended after welding or heavy machining. SHUNFU METAL verifies annealed mechanical properties per EN 10204 3.1 on every heat, with optional EN 10204 3.2 third-party certification (SGS, TUV) under ISO 9001 and API Q1 oversight. 100% ultrasonic testing to EN 10228-3 / ASTM A388 is available.
