17-4PH bar

I. Energy and Electric Power Industry

• Nuclear power field
  • Used to manufacture internal components of nuclear reactors (such as control rods and pressure vessel bolts), it needs to withstand high-temperature radiation and high-pressure corrosive environment (such as cooling water containing boric acid).
  • Typical materials: 316L, Inconel 600 (nickel-based alloy), which have strong chloride ion corrosion resistance and meet nuclear safety standards.
• Thermal power and new energy
  • Bars (such as Super304H, HR3C stainless steel) for high-temperature superheater and reheater pipes in coal-fired power plants are resistant to high temperature above 600℃ and sulfide corrosion.
  • Weather-resistant supports in photovoltaic equipment and distiller parts for seawater desalination are used for their salt fog resistance and oxidation resistance.

II. Petroleum, Chemical Industry and Coal Chemical Industry

• Oil refining and petrochemical plant
  • The internal components of hydrogenation reactor and bolts of catalytic cracking equipment should be resistant to high-temperature hydrogen (400℃+) and hydrogen sulfide corrosion, and commonly used materials are 2507 duplex stainless steel and Hastelloy C-276.
  • Ethylene cracking furnace tubes and pipe fittings are resistant to high temperature above 800℃ and coking corrosion.
• Chemical containers and pipelines
  • 904L stainless steel (high molybdenum content) or titanium alloy bar is used for conveying pipelines and valve shafts with strong corrosive media such as concentrated nitric acid and sulfuric acid to prevent intergranular corrosion.
  • The nozzle and internals of coal gasifier in coal chemical industry are resistant to high-temperature hydrocarbon and acid gas erosion.

III. Aerospace and High-end Manufacturing

• Aircraft engine
  • Nickel-based alloy bars (such as Inconel 718) for turbine blades and combustion chamber components can maintain high strength above 1000℃ and resist gas corrosion.
  • Martensite stainless steel bar (such as 17-4PH) for aircraft landing gear has both high strength and marine atmospheric corrosion resistance.
• Aerospace and military industry
  • Rocket engine nozzle and fuel tank connectors are made of titanium alloy (such as TC4) or special stainless steel, which can withstand extreme temperature changes and oxidant corrosion.

IV. Ocean Engineering and Shipbuilding

• Offshore platforms and equipment
  • The bolts and flanges of deep-sea drilling platforms are made of super duplex stainless steel (such as 2507), which can resist stress corrosion of seawater chloride ions (pitting potential > ＞300mV).
  • The pump shaft and heat exchanger tubesheet of seawater cooling system are made of 6Mo stainless steel (such as N08367), which is resistant to crevice corrosion and biological fouling.
• Key components of ship
  • The exhaust valve of marine diesel engine and turbocharger shaft should be resistant to high temperature exhaust gas (600℃+) and salt corrosion, and austenitic stainless steel (such as 310S) is commonly used.

V. Medical and Food Industry

• Medical equipment
  • Orthopedic implants (such as titanium alloy rods and 316L stainless steel) have biocompatibility and body fluid corrosion resistance, and can be sterilized.
  • The trays and supports of high-temperature sterilization equipment are made of 316L stainless steel bars, which are resistant to steam and disinfectant corrosion.
• food processing
  • The bolts of the stirring shaft and pressure vessel of the high-temperature sterilization kettle are made of 304 or 316 stainless steel, which meets the FDA hygiene standards and resists the corrosion of organic acids and high-temperature steam.

VI. Environmental Protection and Sewage Treatment

• Waste incineration and desulfurization and denitrification
  • High chromium nickel stainless steel (e.g. 310S) is used for incinerator exhaust and flue gas pipeline, which is resistant to high temperature above 800℃ and chloride corrosion.
  • The spray pipe of desulfurization tower and parts of denitration reactor are made of 2205 duplex stainless steel, which is resistant to sulfite and nitrogen oxide corrosion.
• Sewage treatment equipment
  • The reverse osmosis membrane pressure vessel for seawater desalination and the electrode bracket for electrolytic water treatment are made of titanium alloy or 904L stainless steel, which is resistant to chloride ion and electrolytic corrosion.

VII. Machinery and Mould Manufacturing

• High temperature mold
  • Hot-working die steel (such as H13 modified stainless steel) for die-casting dies and injection molding machine nozzles is resistant to erosion and oxidation of molten metal above 500℃.
• Precision mechanical parts
  • Precipitation hardening stainless steel (e.g. 15-5PH) for the shaft and bearing seat of chemical pump is suitable for high-speed rotation, with both high strength (σ b > 1000 MPa) and corrosion resistance.

Comparison of typical materials and characteristics of high alloy stainless steel bar

Summary of core requirements of application scenarios

• High-temperature environment: It is required that the material maintain its strength at high temperature (such as creep strength > 100 MPa @ 500℃) and resist scaling (such as Cr content > 18%).
• Corrosion environment: according to the type of medium (acid, chloride, seawater, etc.), choose the corresponding alloy composition (such as Mo resisting acid corrosion and N improving pitting corrosion resistance).
• Special working conditions: such as high pressure, radiation, alternating load, etc., should be comprehensively designed in combination with the mechanical properties of materials (such as yield strength and fatigue life).