Fuel Cell Interconnector

ZMG®232L is a Fe-22%Cr ferritic alloy with a small addition of special elements for Solid oxide fuel cell (SOFC) interconnector which is alloy-designed and developed to obtain these required properties at the same time.

SOFC is a promising fuel cell with high efficiency operated at high temperature in the range of about 600 to 1000°C(1112 to 1832°F). Good properties are required for SOFC interconnector material as follows;

  • Good electrical conductivity at operating temperature
  • Good oxidation resistance at operating temperature for a long time
  • Coefficient of thermal expansion close to electrolyte material YSZ (zirconia ceramics).

There are some problems for conventional heat-resistant alloys as follows:

  • 430 Stainless Steel does not have sufficient oxidation resistance
  • Austenitic alloys with good oxidation resistance such as In 600 have much higher thermal expansion than YSZ
  • Al-containing ferritic alloys with better oxidation resistance than austenitic alloys have low electrical conductivity of oxide layer.

Chemical Compositions of ZMG®232L (mass %)

Oxidation Resistance & Electrical Contact Resistance Data at 1000°C(1832°F)

Oxidation Resistance and Electrical Contact Resistance in air

Notes:*1 ( ); Exfoliated scale (mg/cm2)
*2 Electrical contact resistance was measured at each oxidation temperature after oxidation.

Oxidation Resistance and Electrical Contact Resistance in air

Microstructure of oxide layer of ZMG232L compared with 430SS

EPMA element map of oxide layer of ZMG232L at 750°C(1382°F) for 6000hrs in air

Physical Properties

Tensile Properties of ZMG232L at Room Temperature to 800°C(1472°F)

page top