Alloy Steel Grade F91 is a high-strength martensitic chromium-molybdenum-vanadium alloy steel developed for advanced high-temperature applications. It provides outstanding creep resistance, fatigue strength, and oxidation resistance at elevated temperatures. Grade F91 is widely used in modern thermal and combined-cycle power plants, particularly for thick-wall piping, headers, and critical pressure components requiring long-term reliability.
MECHANICAL PROPERTIES OF ALLOY STEEL F91 ROUND BAR
Grade
Tensile Strength (MPa) min
0.2% Yield Strength (MPa) min
Elongation (% in 50mm) min
Rockwell B (HRB) max
Brinell (HB) max
F91
585
415
20
—
248 max
💡 Practical Difference in Use
Use Alloy Steel Grade F91 Round Bars when: extremely high-temperature strength, excellent creep resistance, and superior fatigue performance are required. Alloy Steel F91 is a martensitic chromium-molybdenum-vanadium alloy steel developed for advanced power generation and high-pressure steam applications.
→ Example: thick-wall steam piping, boiler headers, turbine components, high-pressure valves, and critical power plant parts.
Bright Finished / Machined Alloy Steel F91 Round Bars when: exceptional dimensional accuracy, smooth surface finish, and precision machining are essential for safety-critical components. Bright bars ensure uniform mechanical properties and improved machinability.
→ Example: valve stems, studs, bolts, shafts, flanges, and precision-machined power plant components.
Applications of Alloy Steel Grade F91 Round Bars
Alloy Steel F91 round bars are extensively used in ultra-high temperature and pressure environments where long-term reliability is essential.
Advanced Power Plants: Thick-wall piping, boiler headers.
