Ferritic stainless steel and manufacturing method thereof

A controlled grain size and γ-fiber (111) phase fraction in ferritic stainless steel, combined with specific alloying and manufacturing processes, addresses the challenges of high-temperature formability and conductivity, ensuring efficient fuel cell performance.

WO2026116814A1PCT designated stage Publication Date: 2026-06-04POHANG IRON & STEEL CO LTD
View PDF 5 Cites 0 Cited by

Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
POHANG IRON & STEEL CO LTD
Filing Date
2025-11-04
Publication Date
2026-06-04

AI Technical Summary

Technical Problem

Existing ferritic stainless steels face challenges in maintaining high electrical conductivity and formability at high temperatures, leading to issues like excessive scale formation, peeling, and reduced fuel cell efficiency due to poor formability and electrical conductivity.

Method used

A ferritic stainless steel composition with controlled grain size and γ-fiber (111) phase fraction, along with specific alloying elements, is manufactured through reheating, hot rolling, and cold rolling processes to form a conductive oxide scale, ensuring excellent formability and conductivity.

Benefits of technology

The solution achieves interfacial contact resistance of 45 mΩcm² or less at 300°C to 900°C, scale layer thickness of 4µm or less, and maintains high electrical conductivity, preventing peeling and enhancing fuel cell efficiency.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure KR2025017893_04062026_PF_FP_ABST
    Figure KR2025017893_04062026_PF_FP_ABST
Patent Text Reader

Abstract

Ferritic stainless steel according to the present invention contains, in wt%, 0.0030-0.0200% of C, 0.0030-0.0200% of N, 0.05-0.40% of Si, 0.10-1.50% of Mn, 19.0-25.0% of Cr, 0.01-2.00% of Mo, 0.05-1.00% of Nb, and 0.010-0.200% of Ti, with the remainder comprising Fe and inevitable impurities, has average grain size of 40 µm or less in a cross-section perpendicular to the rolling direction, has 45% or more of a γ-fiber(111) phase by area fraction, and satisfies expressions (1) and (2). Expression (1): 35.0 ≤ [Cr] / [Mn] ≤ 60.0 Expression (2): ([Cr] / [Mn]) / (3[Si]) ≥ 40.0 (where [Cr], [Mn], and [Si] are wt% of respective elements)
Need to check novelty before this filing date? Find Prior Art