309S stainless steel ferrules and fittings are specialized components engineered for erosion shielding in superheater and reheater tube assemblies of power boilers. Manufactured from low-carbon SS309S—a variant of SS309 with enhanced weldability—they provide excellent resistance against high-temperature oxidation and carbide precipitation.

Containing approximately 23% chromium and 13% nickel, SS309S maintains structural integrity and anti-corrosion properties in temperatures up to 1000–1100°C (1832–2012°F). These ferrules are widely used to protect tube ends, elbows, and entry zones from abrasive flue gas and fly ash impact.

Key Features

High-Temperature Resistance: Designed for continuous use in zones exceeding 1000°C.
Anti-Erosion Performance: Shields critical boiler zones from flue gas turbulence and fly ash abrasion.
Low-Carbon Advantage: S-grade formulation minimizes sensitization and improves weldability.
Precision Machining: Available in both standard and custom geometries for precise installation.
Superior Durability: Outperforms SS304 and SS321 under thermally aggressive boiler conditions.

Why Choose 309S Stainless Ferrules for Erosion Shielding?

309S stainless steel is the ideal solution for superheater erosion shields operating in high-temperature steam and combustion atmospheres. Its low carbon content enhances post-weld corrosion resistance, while its high Cr-Ni matrix delivers excellent oxidation protection and mechanical strength.

Incorporating 309S ferrules in boiler assemblies significantly extends tube life, reduces erosion-induced failures, and improves system reliability. They are easy to install, replace, and maintain—making them a cost-effective and dependable solution for modern heat recovery applications.

Stainless Steel 309 / 309S / 309H

Technical specifications including chemical composition, mechanical and thermal properties.

Chemical composition of grade 309 stainless steels.
Grade	C	Mn	Si	P	S	Cr	Ni	Fe
SS 309	0.20 max	2.0 max	0.75 max	0.045 max	0.030 max	22.0 – 24.0	12.0 – 15.0	Balance
SS 309S	0.08 max	2.0 max	0.75 max	0.045 max	0.030 max	22.0 – 24.0	12.0 – 15.0	Balance

Physical properties of SS 309 stainless steels.
Property	Metric	Imperial
Density	8 g/cm³	0.289 lb/in³
Melting Point	1455°C	2650°F

Physical properties of SS 309 stainless steels, including density, thermal expansion, and specific heat.

Mechanical properties of SS 309 stainless steels.
Property	Metric	Imperial
Tensile Strength	620 MPa	89,900 psi
Yield Strength (0.2%)	310 MPa	45,000 psi
Izod Impact	120–165 J	88.5–122 ft-lb
Shear Modulus	77 GPa	11,200 ksi
Elastic Modulus	200 GPa	29,008 ksi
Poisson’s Ratio	0.27 – 0.30	0.27 – 0.30
Elongation at Break	45%	45%
Hardness, Brinell	147	147
Hardness, Rockwell B	85	85
Hardness, Vickers	169	169

Thermal properties of SS 309 stainless steels.
Property	Metric	Imperial
Thermal Expansion Coefficient (0–100°C)	14.9 μm/m·°C	8.28 μin/in·°F
Thermal Conductivity (0–100°C)	15.6 W/m·K	108 BTU in/hr·ft²·°F

Equivalent standards for SS 309 stainless steels.
Standard 1	Standard 2	Standard 3	Standard 4
ASTM A167	ASME SA249	ASTM A314	ASTM A580
ASTM A249	ASME SA312	ASTM A358	FED QQ-S-763
ASTM A276	ASME SA358	ASTM A403	FED QQ-S-766
ASTM A473	ASME SA403	ASTM A409	MIL-S-862
ASTM A479	ASME SA409	ASTM A511	SAE J405 (30309)
DIN 1.4828	ASTM A312	ASTM A554	SAE 30309