EN 10216-5 1.4841 Stainless Steel Seamless Tube for Elevated Temperature Service

What Is 1.4841

Material number 1.4841, designated X15CrNiSi25-21, is a high-chromium, high-nickel austenitic heat-resistant steel strengthened by an elevated silicon content. Supplied as seamless tube under EN 10216-5, it is intended for pressure-bearing and process equipment operating at high temperatures where oxidation resistance and structural stability are decisive. It is the European counterpart of the 25Cr-21Ni silicon-bearing family represented in the United States by UNS S31400.

Chemical Composition

The composition limits are carbon 0.20 percent maximum, silicon 1.5 to 2.5 percent, manganese 2.0 percent maximum, phosphorus 0.045 percent maximum, sulfur 0.015 percent maximum, chromium 24.0 to 26.0 percent, and nickel 19.0 to 22.0 percent. The high chromium and nickel contents form a dense, stable oxide scale, and silicon further improves scale adherence and resistance to oxidation in cyclic thermal service.

Mechanical Properties

In the solution-annealed condition the tensile strength is 500 to 700 MPa with a minimum yield strength of 230 MPa and a minimum elongation of 25 percent. The austenitic structure retains useful creep and stress-rupture strength at elevated temperatures, allowing continuous service in oxidizing atmospheres up to about 1050 degrees C depending on stress level and atmosphere.

Manufacturing and Tolerances

Tubes are produced by hot finishing or cold finishing followed by solution annealing and pickling or bright annealing. EN 10216-5 classifies outside diameter tolerances into grades D1 to D4 and wall thickness tolerances into grades T1 to T4, with the tightest classes available on request. Testing categories TC1 and TC2 define the required inspection level, including dimensional, surface, and non-destructive examination.

Applications

1.4841 seamless tube is used for furnace components, burner heads and nozzles, radiant tubes, heat exchanger tubes, flue gas ducts, and furnace internals in the heat treatment, petrochemical, and power industries, as well as for kiln and incineration equipment operating at sustained high temperature.

Procurement Guidance

Specify the outside diameter and wall thickness classes, the testing category, and the required finish. Confirm the maximum service temperature and atmosphere against the design specification, and request mill test certificates covering composition and mechanical properties.

Frequently Asked Questions

Q: What is material 1.4841?

A: X15CrNiSi25-21, a high-silicon heat-resistant austenitic steel.

Q: What standard governs 1.4841 seamless tube?

A: EN 10216-5 for pressure purposes.

Q: What is the composition of 1.4841?

A: Chromium 24 to 26 percent, nickel 19 to 22 percent, silicon 1.5 to 2.5 percent.

Q: What service temperature suits 1.4841?

A: Continuous oxidizing service up to about 1050 degrees C.

Q: What are the tolerance classes?

A: Outside diameter D1 to D4 and wall thickness T1 to T4 per EN 10216-5.

Q: What applications use 1.4841 tubes?

A: Furnace components, burner heads, radiant tubes, and heat exchanger tubes.

Contact us for 1.4841 seamless tubes in your required size, tolerance class, and testing category.