347 Stainless Steel Bar

Product Overview

347 stainless steel bar is a niobium-stabilized austenitic stainless steel that offers exceptional resistance to intergranular corrosion, especially after welding and long-term high-temperature exposure. 🧪 It is particularly suitable for use in pressure vessels, chemical processing systems, and high-temperature environments where stabilization against carbide precipitation is essential.

Available Sizes

• 📏 Type: Round bar, Square bar, Flat bar, Hex bar
• 📐 Diameter (Round): 6mm – 250mm
• 📏 Length: 1000mm – 6000mm (customizable)
• 🎯 Tolerances: h9, h10, h11 (as requested)
• 📚 Standards: ASTM A276, ASTM A479, ASTM A564, EN 10088-3

Chemical Composition

Element	Content (%)
C	≤ 0.08
Si	≤ 1.00
Mn	≤ 2.00
P	≤ 0.045
S	≤ 0.030
Cr	17.0 – 19.0
Ni	9.0 – 13.0
Nb + Ta	≥ 10 × C (min)

Mechanical Properties

Property	Value (Annealed)
Tensile Strength	≥ 515 MPa
Yield Strength	≥ 205 MPa
Elongation (%)	≥ 40%
Hardness (HB)	≤ 217

Features & Advantages

• ✅ Excellent resistance to intergranular corrosion after welding
• 🔥 Withstands prolonged high-temperature service
• ⚙️ Niobium stabilized to prevent chromium carbide precipitation
• 🛠️ Good weldability and mechanical strength
• 📏 Maintains structural integrity under thermal cycling

Applications

Surface Finish

• 🖤 Black
• 🧼 Pickled
• ✨ Bright
• 🔧 Polished (180#, 240#, 320#)
• 🌀 Peeled / Turned / Ground

Processing Services

• ✂️ Length cutting to customer specification
• 🧽 Surface grinding and polishing
• 🔩 Heat-resistant machining
• 📏 Tolerance control and straightening
• 🔧 End machining and threading