1Cr18Ni9Ti tube shields are manufactured from a titanium-stabilized austenitic stainless steel known for its excellent corrosion resistance, high-temperature strength, and durability in harsh industrial environments. This steel grade, equivalent to ASTM 321 (SS321), contains chromium (~18%), nickel (~9%), and titanium additives that prevent carbide precipitation during welding and prolonged heating.

These shields are engineered to protect boiler tubes, reheaters, and economizer components from erosive particle impacts and corrosive flue gases commonly encountered in power plants, chemical refineries, and waste incineration systems.

By stabilizing the alloy with titanium, 1Cr18Ni9Ti tube shields maintain their mechanical integrity and corrosion resistance even after long-term exposure to temperatures up to 900°C (1650°F), especially in oxidizing and carburizing atmospheres.

1Cr18Ni9Ti (321) Stainless Steel

1Cr18Ni9Ti (SUS321) is an austenitic stainless steel widely used in China. Its designation reflects its composition: ~0.1% C, 18% Cr, and 9% Ni, with titanium added to enhance resistance to intergranular corrosion.

321 Tube Shields for CFB Boilers (Superheater Protection)
OEM Erosion Shields made of 1Cr18Ni9Ti / Cr25Ni20

Why Was 1Cr18Ni9Ti Introduced and Why Is It Being Replaced?

Due to intergranular corrosion issues in early 304 steels, titanium was added to bind carbon and prevent Cr23C6 formation. This innovation formed 1Cr18Ni9Ti. However, advancements in smelting allowed for low-carbon stainless grades like 304 (0Cr18Ni9) to become viable alternatives. 304 now dominates many industries worldwide, although 321 is still used in certain Chinese enterprises.

GB Standard Composition of SUS321
Element	Content (%)
Carbon (C)	≤ 0.12
Silicon (Si)	≤ 1.00
Manganese (Mn)	≤ 2.00
Phosphorus (P)	≤ 0.035
Sulfur (S)	≤ 0.030
Chromium (Cr)	17.00 – 19.00
Nickel (Ni)	9.00 – 12.00
Titanium (Ti)	≥ 5 × C

Mechanical Properties of 1Cr18Ni9Ti
Property	Value	Unit
Tensile Strength	≥ 520	MPa
Yield Strength	≥ 205	MPa
Elongation	≥ 40	%
Hardness	≤ 187	HB

Comparison: 1Cr18Ni9Ti (321) vs 0Cr18Ni9 (304)

Both are austenitic grades, but 321 contains titanium for better high-temperature resistance and intergranular corrosion protection, whereas 304 is more cost-effective and common.

Property	321 (1Cr18Ni9Ti)	304 (0Cr18Ni9)
Stabilizer	Titanium (Ti)	None
Corrosion Resistance	High (Intergranular)	Excellent (General)
High-Temperature Use	Up to 900°C	Up to 800°C
Mechanical Properties	520/205 MPa	520/205 MPa
Weldability	Good (Post-weld treatment advised)	Excellent (No treatment required)
Applications	Aerospace, high-temp piping	Food, chemical, general structures
Cost	Higher	Lower