AISI 347 / 1.4550 Stainless Steel

✅ General Technical Characteristics

Stainless steel AISI 347 (EN 1.4550, 08X18H12B) is a niobium-stabilized austenitic stainless steel that offers excellent resistance to intergranular corrosion, particularly in high-temperature environments. The addition of niobium prevents carbide precipitation, making this alloy ideal for prolonged exposure to elevated temperatures and aggressive chemical environments.

Main Characteristics:

• High resistance to intergranular corrosion and oxidation.
• Excellent thermal stability and resistance to carbide precipitation.
• Enhanced mechanical strength at high temperatures.
• Good weldability and machinability.
• Suitable for prolonged use in temperatures up to 900°C.

🔬 Chemical Composition AISI 347 / EN 1.4550 (%):

• Carbon (C): ≤ 0.08
• Silicon (Si): ≤ 1.0
• Manganese (Mn): ≤ 2.0
• Phosphorus (P): ≤ 0.045
• Sulfur (S): ≤ 0.015
• Chromium (Cr): 17.0 – 19.0
• Nickel (Ni): 9.0 – 13.0
• Niobium (Nb): 10 x C minimum

💡 The presence of niobium improves high-temperature performance and prevents intergranular corrosion after welding.

🏭 Applications

Steel AISI 347 (EN 1.4550, 08X18H12B) is widely used in industries that require superior heat resistance, strength, and corrosion resistance.

Main Application Areas:

• Aerospace and aviation industry (exhaust manifolds, turbine components).
• Chemical and petrochemical industry (reactors, heat exchangers, pipelines).
• Power generation (boilers, steam piping, superheater tubes).
• Food and pharmaceutical industries (sterile processing equipment).
• Automotive and transport industry (exhaust systems, catalytic converters).

📊 Mechanical Properties

• Tensile Strength (Rm): 500 – 750 MPa
• Yield Strength (Rp0.2): ≥ 210 MPa
• Hardness (HB): ≤ 220 HB
• Elongation (A5): ≥ 40 %

⭐ Features

• High corrosion and oxidation resistance – performs exceptionally well in aggressive environments.
• Heat resistance – maintains mechanical properties at temperatures up to 900°C.
• Superior weldability – niobium stabilization prevents carbide precipitation.
• Mechanical strength – withstands extreme thermal and mechanical loads.
• Versatility – suitable for industrial, aerospace, and automotive applications.

AISI 347 / EN 1.4550 steel delivery forms

(No. 1.4546.9 AISI 347 / AMS 5646