What Is 347 (UNS S34700) Stainless Steel

347 (UNS S34700, 1.4550, SUS347) is niobium-tantalum stabilized austenitic stainless steel, with better high-temp stability than titanium-stabilized grades.

Equivalent Grades (Horizontal)

UNS: S34700 | JIS: SUS347 | GB: 06Cr18Ni11Nb | EN: X6CrNiNb18-10

Chemical Composition (wt%, Horizontal)

C: ≤0.08 | Si: ≤1.00 | Mn: ≤2.00 | P: ≤0.045 | S: ≤0.030 | Cr: 17.00-19.00 | Ni: 9.00-13.00 | Nb+Ta: 8×C-1.00 | Fe: Balance

UNS No	Grade	C	Si	Mn	P	S	Cr	Mo	Ni	N	Other
S34700	347	0.08	0.75	2.00	0.045	0.030	17.00/19.00	–	9.00/13.00	–	Cb:10xC1.00

Key Properties (20°C, Annealed, Horizontal)

Density: 7.93g/cm³ | Melting Point: 1400-1450°C | Tensile Strength: ≥515N/mm² | 0.2% Yield Strength: ≥205N/mm² | Elongation: ≥40% | Hardness (HB): ≤201

Core Characteristics

Excellent post-weld intergranular corrosion resistance; superior high-temp stability (up to 900°C); good weldability; suitable for high-temp industrial and nuclear applications.

321 vs 347 (Horizontal)

Stabilizer: 321 (Titanium) | 347 (Niobium+Tantalum) | High-Temp Stability: 321 (Good) | 347 (Superior) | Applications: 321 (General high-temp) | 347 (Nuclear/high-temp)

 

Stainless Steel Suppliers

If you have project requirements for stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

 

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
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