1Cr25Ni20Si2 tube shields, also known as boiler tube shields, anti-erosion shields, or anti-corrosion shields, are critical components engineered to protect boiler tubes from erosion, corrosion, and abrasion caused by high-temperature flue gases and fly ash. These shields are widely applied in power plants, waste-to-energy systems, and petrochemical boilers operating under extreme thermal and chemical conditions.

Manufactured from 1Cr25Ni20Si2 stainless steel—a heat-resistant alloy containing approximately 25% chromium, 20% nickel, and 2% silicon—the shields provide outstanding oxidation resistance and structural stability at temperatures up to 1100°C. Silicon enhances the formation of a protective oxide film, while chromium and nickel improve high-temperature corrosion resistance and mechanical strength. Note: embrittlement may occur in the 600–800°C range.

Available in various forms—straight, inner-curve, outer-curve, side-curve, and S-curve—these shields are customized to fit boiler tubes with outer diameters ranging from 32mm to 89mm. Common lengths range from 1000mm to 2000mm, with wrap angles from 90° to 240°. The shield’s internal diameter is typically 1–3mm larger than the tube it covers, ensuring a snug and reliable fit.

High-precision bending, stamping, and mold shaping processes are used to produce smooth, weldable surfaces. Snap rings made from 1Cr25Ni20Si2 or similar alloys are spot-welded every 200–500mm along the shield’s arc to ensure secure placement. Coatings such as chromium carbide may be applied to further enhance surface wear resistance for ultra-harsh conditions.

These shields play a vital role in reducing unplanned maintenance, extending tube life, and increasing thermal system reliability. Applications include superheaters, reheaters, economizers, and water-cooled walls in circulating fluidized bed (CFB) boilers, biomass plants, and fossil-fuel systems. Each shield complies with GB 4238 (heat-resisting steel sheets) and GB/T 1221 (heat-resisting steel bars), and undergoes PMI verification to ensure compliance.

Product Summary

Excellent oxidation and scaling resistance
Operates continuously at temperatures up to 1100°C
Customizable shapes and lengths (20–3000mm)
Compatible with common boiler tube sizes: 32–89mm
Enhanced wear resistance with optional carbide coating

Why Choose 1Cr25Ni20Si2?

Compared to standard stainless grades such as SS304 or SS321, 1Cr25Ni20Si2 offers superior resistance to thermal cycling, intergranular corrosion, and chemical attack in aggressive flue gas environments. It’s the optimal solution for extending service life and reducing boiler maintenance frequency in extreme industrial conditions.

Note: Avoid prolonged use in the 600–800°C range due to risk of phase embrittlement. Proper material selection and welding parameters are essential for optimal performance.

1Cr25Ni20Si2 Stainless Steel

1Cr25Ni20Si2 is an austenitic stainless steel with excellent high-temperature strength and oxidation resistance. However, it is sensitive to sulfur-containing environments and exhibits precipitation embrittlement in the range of 600–800°C, making it ideal for manufacturing furnace components under stress.

Basic Information

Grade: 1Cr25Ni20Si2
Old Standard: GB/T 1221-1992
New Standard: GB/T 1221-2007 → New designation: 16Cr25Ni20Si2
Application: Furnace parts, heat-resistant structures, anti-oxidation under stress