SUS347 Stainless Steel Chemical Composition, Yield Strength
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What is SUS347 material?
SUS347 stainless steel is a columbium-stabilized austenitic grade with key elements like 17-19% Chromium, 9-13% Nickel, and Niobium (Nb) stabilizing carbon, giving it excellent high-temp strength and corrosion resistance; its typical yield strength is around 205 MPa (30 ksi) minimum in the annealed condition, though it can vary slightly by product form and standard, often paired with tensile strength ~515 MPa (75 ksi).
What is the composition of SUS 347 stainless steel?
SUS 347 stainless steel is a niobium/tantalum-stabilized austenitic steel, primarily composed of Iron (Balance), Chromium (17-19%), Nickel (9-13%), with stabilizing elements Niobium + Tantalum (min 10x Carbon), plus smaller amounts of Manganese, Silicon, Phosphorus, and Sulfur.
| Element | Composition Range |
| Carbon (C) | ≤ 0.08% |
| Manganese (Mn) | ≤ 2.00% |
| Silicon (Si) | ≤ 1.00% |
| Chromium (Cr) | 17.0% – 19.0% |
| Nickel (Ni) | 9.0% – 13.0% |
| Sulfur (S) | ≤ 0.030% |
| Phosphorus (P) | ≤ 0.045% |
| Niobium (Nb) + Tantalum (Ta) | 10x C min – 1.0% max |
What is the yield strength of SUS 347 stainless steel?
The yield strength of SUS 347 stainless steel (also known as Type 347) typically starts at a minimum of 30,000 psi (205 MPa) in the annealed condition, as specified by standards like ASTM A240 for plates, though values can range slightly higher (e.g., 36.5 ksi or 43.7 ksi) depending on product form (bar, sheet) and specific processing, but 30 ksi is a common minimum for general use.
Mechanical Properties
| Property | Value |
| Tensile Strength (UTS) | 515 MPa min (75 ksi min) |
| Yield Strength (0.2% Offset) | 205 MPa min (30 ksi min) |
| Elongation | 40% min |
| Hardness (Brinell) | 201 max |
| Hardness (Rockwell B) | 95 max |
| Modulus of Elasticity | 190 – 210 GPa (27557 – 30458 ksi) |
| Poisson's Ratio | 0.27 – 0.30 |
| Creep Strength (at 750°C) | 38 – 39 MPa (5510 – 5660 psi) |
| Rupture Strength (at 750°C) | 38 – 39 MPa (5510 – 5660 psi) (100,000 hours) |
| Impact Toughness (Charpy V-notch) | 60 J (Longitudinal) / 40 J (Transverse) |
| Fatigue Strength (Rotating Bending, at 20°C) | 240 MPa (34.8 ksi) |
What is the density of SUS 347 stainless steel?
The density of SUS 347 stainless steel is approximately 0.288 lbs/in³ (pounds per cubic inch) or 7.96 g/cm³ (grams per cubic centimeter) at room temperature, though values can range slightly from 0.285 to 0.289 lbs/in³ depending on the specific form and supplier.
Physical Properties
| Property | Value |
| Density | 7.7 – 8.03 g/cm³ (0.278 – 0.290 lb/in³) |
| Melting Point | 1371 – 1400°C (2500 – 2550°F) |
| Thermal Conductivity | 16.3 W/m·K (212°F) |
| Coefficient of Thermal Expansion | 10.5 x 10⁻⁶/°C (20-600°C) |
| Electrical Resistivity | 72 µΩ·cm (20°C) |
| Specific Heat | 500 J/kg·K (0 – 100°C) |
Is SUS347 stainless steel magnetic?
SUS347 stainless steel is primarily non-magnetic in its annealed (softened) state because it's an austenitic grade, but it can become slightly magnetic after cold working (bending, forming) due to changes in its crystal structure.
What is the difference between 316 and 347 stainless steel?
The main difference is their stabilizing element: 316 adds Molybdenum for superior chloride/pitting corrosion resistance, while 347 adds Niobium (Columbium) for enhanced high-temperature stability and weldability, preventing intergranular corrosion in heat-affected zones better than 316. Choose 316 for marine/chlorine environments; choose 347 for high-heat/welding applications where sensitization is a risk.
What is the difference between SS 347 and 304 stainless steel?
304 stainless steel is the most commonly used stainless steel, and is well suited for general-purpose applications such as kitchen equipment and food processing, but it lacks the stability required for environments above 800°F (427°C). 347 contains niobium, which resists intergranular corrosion and is suitable for high-temperature service. While 304 is a more economical choice for everyday use, 347 is the preferred choice for high temperatures and corrosive environments.
Does 347 Stainless Steel Rust?
Due to its high chromium content and stabilization with niobium, 347 stainless steel is highly resistant to rust and corrosion. But it will, as with all stainless steels, suffer from localized pitting or crevice corrosion at high chloride concentrations.
GNEE currently has SUS 347 (UNS S34700) products in stock, including: plates, sheets, coils, strips, tubes, bars, and wires. In addition, we offer a variety of surface finishes for you to choose from, such as: No.1, 2B, 2D, BA, No.3, No.4, HL, No.8, sandblasting, etc.
We guarantee 100% quality. We will never deliver any defective products to our customers. Please feel free to contact us to customize your required product specifications, including shape, condition, surface treatment, and processing techniques.
