P91 (9Cr-1Mo-V): Creep-Strength Enhanced Ferritic Stahl für USC Boilers

ASME SA335 P91 / ASTM A335 P91 · Published: 2026-06-02 · Updated: July 2026

Quick Reference

P91 (Grade 91) enabled ultra-supercritical power plants at 620°C steam — 50-60°C higher than 2.25Cr-1Mo. MX carbonitride precipitates (V/Nb(C,N)) provide creep strength. Welding demands precise PWHT at 750°C — failure causes Type IV cracking...

P91 (Güte 91) enabled ultra-supercritical power plants bei 620°C steam — 50-60°C higher als 2.25Cr-1Mo. MX carbonitride precipitates (V/Nb(C,N)) bereitstellen creep strength. Welding demands precise PWHT bei 750°C — failure causes Typ IV cracking innerhalb 10,000 hours.

Quick Facts

KategorieLegierungsstahl
NormASME SA335 P91 / ASTM A335 P91
Density7770 kg/m³
Yield Strength415 MPa (min)
Tensile Strength585 MPa (min)

Global Equivalents & Cross-Reference

Alternative Standard / GradeAction
SA335 P91 Compare
EN X10CrMoVNb9-1 Compare

Verwandt Materials

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Frequently Asked Questions

Warum ist P91 welding so sensitive?

MX precipitates dissolve während welding. PWHT zu niedrig: incomplete re-precipitation. PWHT zu hoch: martensite→ferrite transformation, permanently reducing strength.

References & International Standards

  • ASTM International. Norm Specifications für Stahl & Metal Alloys. astm.org
  • International Organization für Standardization (ISO). Metallic Materials — Cross-Referenz Database. iso.org
  • American Iron und Stahl Institute (AISI). Stahl Güte Designations & Equivalents. steel.org
  • European Committee für Standardization (CEN). EN Stahl Standards & Numbering System. cencenelec.eu