Substrate stainless steel sheet for fuel cell separators and production method therefor

Patent metadata

Field	Value
Publication number	US-11380907-B2
Application number	US-201816483147-A
Country	US
Kind code	B2
Filing date	Jan 25, 2018
Priority date	Feb 9, 2017
Publication date	Jul 5, 2022
Grant date	Jul 5, 2022

Abstract

A substrate stainless steel sheet has [chemical form other than metal (Cr+Fe)]/[metal form (Cr+Fe)] of 12.0 or more and 200 or less, [chemical form other than metal (Cr+Fe)]/[metal form (Cr+Fe)] being a ratio of a total of Cr and Fe existing in chemical form other than metal to a total of Cr and Fe existing in metal form at a substrate stainless steel sheet surface.

First claim

The invention claimed is:

1. A production method for a substrate stainless steel sheet for fuel cell separators, comprising:
preparing a stainless steel sheet as a material; and
subjecting the stainless steel sheet to heat treatment of holding in an atmosphere containing 1 vol. % or more oxygen and in a temperature range of 350° C. or more to 500° C. or less for 1 second or more and 120 seconds or less to thereby set [chemical form other than metal (Cr+Fe)]/[metal chemical form (Cr+Fe)] at 12.0 or more and 200 or less, [chemical form other than metal (Cr+Fe)]/[metal chemical form (Cr+Fe)] being a ratio of a total of Cr and Fe existing in chemical form other than metal to a total of Cr and Fe existing in metal chemical form at a stainless steel sheet surface,
wherein [metal chemical form (Cr+Fe)] is a total atomic concentration of Cr and Fe existing in metal chemical form and [chemical form other than metal (Cr+Fe)] is a total atomic concentration of Cr and Fe existing in chemical form other than metal, which are measured by analyzing the stainless steel sheet surface after heat treatment by X-ray photoelectron spectroscopy, and
wherein the substrate stainless steel sheet is in a state before a conductive coating is formed on its surface.

2. The production method according to claim 1 , wherein the temperature range of the heat treatment is 350° C. or more to 450° C. or less.

3. The production method according to claim 1 , wherein the substrate stainless steel sheet does not have the conductive coating on its surface.

4. The production method according to claim 2 , wherein the substrate stainless steel sheet does not have the conductive coating on its surface.

5. The production method according to claim 1 , wherein a heat treatment time of the heat treatment is 1 second or more and 1 minute or less.

6. The production method according to claim 2 , wherein a heat treatment time of the heat treatment is 1 second or more and 1 minute or less.

7. The production method according to claim 3 , wherein a heat treatment time of the heat treatment is 1 second or more and 1 minute or less.

8. The production method according to claim 4 , wherein a heat treatment time of the heat treatment is 1 second or more and 1 minute or less.

Assignees

• Jfe Steel Corp

Inventors

• Yano Takayoshi
• Ishikawa Shin

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• Y02E60/50

  Fuel cells · CPC title

• C22C38/42

  with copper · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• C21D1/76

  Adjusting the composition of the atmosphere · CPC title