Premium Low-CarbonStainless Steel 310S

Stainless Steel 310S is a premium low-carbon austenitic grade with ultra-high Cr (24–26%) and Ni (19–22%), built for 1150°C service. The "S" (≤0.08%C) prevents intergranular corrosion, making it indispensable for extreme-heat industries like jet engine manufacturing and petrochemical processing.

Chemical Composition (Key, % ASTM A240): C≤0.08; Cr24.0–26.0; Ni19.0–22.0; Si≤1.5; Mn≤2.0

Mechanical Properties (Annealed): Tensile Strength≥515MPa; Yield Strength≥205MPa; Elongation≥40%; Hardness≤217HB

Performance Advantages: 1150°C oxidation resistance; excellent creep resistance; low carbon avoids intergranular corrosion; stable in thermal cycling.

Applications: Jet exhausts, kiln liners, high-temperature reactors, incinerator parts.

Equivalent Grades: EN1.4845, JIS SUS310S, DIN X2CrNi25-21

Comparison with 309S: 310S sags 50% less at 1000°C; 1150°C service (309S max 980°C) but costs 20–30% more.

FAQs

Why can 310S withstand 1150°C? Its 24–26% Cr forms a dense, self-healing Cr₂O₃ layer that blocks oxidation-far more stable than 304's layer (fails above 650°C). 19–22% Ni stabilizes the austenitic structure, preventing brittleness at high temps. Low carbon (≤0.08%) avoids impurity-induced oxide layer damage. The Cr/Ni synergy keeps the layer intact during prolonged extreme heat.

 

What is creep resistance, and why is 310S superior? Creep is slow deformation under high heat/stress-critical for furnace belts/jet parts. 310S's high Ni slows atomic movement; fine austenitic grains minimize grain boundary sliding (a key creep cause). At 1000°C, a 310S furnace belt sags half as much as 309S over the same period, reducing replacements and maintenance costs despite higher initial prices.

 

Is 310S corrosion-resistant in non-high-heat scenarios? It resists atmospheric rust, dilute nitric acid, and alkalis, fitting non-aggressive chemical tanks. But no molybdenum makes it poor in chlorides-avoid marine/saltwater use (prone to pitting). Sulfur gases at high temps form brittle sulfides, limiting use in sulfur-rich environments. It excels only in low-chloride, ultra-high-heat conditions.

How to weld 310S successfully? Hot cracking is a risk (narrow solidification range). Use low-sulfur 310S filler; low heat input reduces HAZ size and impurity segregation. Argon shielding prevents porosity. Thick sections need 100–150°C preheat to reduce stress. Post-weld, grind/pickle to remove oxide scale and restore corrosion resistance; avoid excessive electrode weaving.

 

Why is 310S expensive, and when is it worth it? High Cr/Ni (19–22% Ni vs. 304's 8–10.5%) drives costs. It's justified for ≥1000°C service: jet exhausts use it instead of costly superalloys; industrial kilns see 2–3x longer life than 309S. Cheaper grades (309S) fail in ultra-high heat, causing frequent downtime-310S's longevity offsets its price.