TP310HCbN (UNS S31042), also known by the trade name HR3C, is a high-grade austenitic 25Cr-20Ni-N stainless steel designed for use in severe high temperature service applications such as superheaters, reheaters and heat exchanger tubes. This alloy with the specified composition is manufactured to ASTM A213 / ASME SA213 standards, and the alloy exhibits much improved creep strength and steam oxidation resistance when compared with conventional TP310H and 18Cr-8Ni stainless steels. It has been proven to operate continuously in advanced supercritical and ultra-supercritical power plants at steam temperature around 620 °C and above. USA Piping Solution is a trusted manufacturer and supplier of seamless pipes and tubes of TP310HCbN (UNS S31042) which are precision engineered with complete and dependable material traceability, certification (EN 10204 3.1) and third party inspection for critical power generation and industrial applications.
Specifications of TP310HCbN (UNS S31042) Pipe and Tube
| Specification | Details |
|---|---|
| Product Name | TP310HCbN / UNS S31042 / HR3C Seamless Boiler Tubes |
| Material Grade | TP310HCbN, UNS S31042, W.Nr. 1.4952, HR3C (25Cr-20Ni-Nb-N) |
| Governing Standards | ASTM: A213 / A213M (Seamless Alloy Boiler & Superheater Tubes), A312 ASME: SA213, SA312 |
| Manufacturing Process | Seamless (Cold Drawn, Cold Rolled, Hot Finished) |
| Product Forms | Superheater Tube, Reheater Tube, Boiler Tube, Heat Exchanger Tube, USC Power Piping |
| Outside Diameter (OD) | 15.88 mm to 127.0 mm (5/8" OD to 5" OD) |
| Wall Thickness | 1.65 mm to 15.0 mm (0.065" to 0.590" Minimum Wall Thickness) |
| Length | Single Random, Double Random, Cut Lengths (Up to 12 Meters) |
| Heat Treatment | Solution annealed at 1180 °C (2156 °F) minimum, followed by rapid cooling |
| Service Temperature | Designed for main steam temperatures around 620 °C and above in advanced supercritical and ultra-supercritical plant. Maximum metal wall temperature is higher than the steam temperature and should be taken from the boiler design, not from a single headline figure. |
| End Finish | Plain end (PE), bevelled end (BE), threaded end |
| Surface Finish | Solution Annealed & Pickled (AP), Bright Annealed (BA), Polished |
| Testing & Inspection | PMI Testing, Hydrostatic Test, Eddy Current / Ultrasonic Testing (UT), Grain Size Measurement (ASTM E112 ≥ No. 7), Intergranular Corrosion (IGC) Test, Tensile & Hardness Testing |
| Certifications | EN 10204 3.1 Mill Test Certificate (MTC), Third-Party Inspection (TPI) |
| Packaging | Seaworthy Wooden Crates, Wrapped Bundles with Plastic End Caps |
Applications and Industrial Uses of TP310HCbN (UNS S31042) Pipe and Tube
- Superheaters and Reheaters in Power Plants
- Ultra-Supercritical (USC) Boiler Systems
- High-Temperature Steam Piping
- Heat Exchangers and Boiler Tubes
- Petrochemical Processing Plants
- Oil & Gas Refinery Heater Tubes
- Industrial Furnaces and Heat Treatment Equipment
- Thermal Power Generation Facilities
Frequently Asked Questions
1. What is TP310HCbN (UNS S31042)?
TP310HCbN (UNS S31042) is a high-temperature austenitic stainless steel used for boiler tubes, superheaters, and reheaters. It offers excellent creep strength and oxidation resistance.
2. What is the difference between TP310H and TP310HCbN?
TP310HCbN contains added niobium (Nb) and nitrogen (N), giving it better creep strength and higher oxidation resistance than standard TP310H.
3. Can TP310HCbN be used in superheater and reheater tubes?
Yes. TP310HCbN is specifically designed for superheater and reheater tubes operating under high temperatures and high steam pressure.
4. Why is TP310HCbN preferred for ultra-supercritical boilers?
TP310HCbN is preferred because it provides excellent high-temperature strength, long-term creep resistance, and superior oxidation resistance, making it ideal for ultra-supercritical boiler systems.
5. Is TP310HCbN the same as HR3C?
Yes. TP310HCbN is the ASTM/ASME designation under UNS S31042, while HR3C is the common trade name. Both refer to the same 25Cr-20Ni austenitic stainless steel with niobium and nitrogen additions, covered by ASTM A213 and ASME SA-213.
6. What is the difference between TP310HCbN and Super 304H?
Both are austenitic grades used in ultra-supercritical boilers. Super 304H contains about 18% chromium and 9% nickel with copper additions, while TP310HCbN contains about 25% chromium, providing better steam oxidation resistance for higher-temperature service.
7. Does TP310HCbN require special handling during fabrication?
Yes. It is solution annealed at 1180°C minimum, so bending, welding, and subsequent heat input should follow qualified boiler fabrication procedures. Grain size should also be verified on the mill certificate.