Sandvik Sanergy HT 441

Sandvik’s advanced state-of-the-art roll to roll coating lines for mass production combined with commercially available 441-type stainless steel provides an outstanding opportunity for the cost-effective industrial mass production of interconnects for solid oxide fuel cells.

Benefits of Sandvik coated steel strip

Compared to uncoated stainless steel our cerium-cobalt coating reduces the chromium evaporation by up to one order of magnitude (see graph 1), increasing the long time efficiency of the fuel cell. Sanergy HT 441 also has excellent oxidation performance and surface conductivity compared to uncoated stainless steel. Together these factors rule out the need for expensive special steels or alloys.

Graph 1. Accumulative chromium evaporation for uncoated and cerium-cobalt coated 441 stainless steel. Chromium evaporation data from J.G. Grolig, J. Froitzheim, J.-E. Svensson, Journal of Power Sources, 248, 2014, p. 1007-1013.

Good adhesion of the coating enables the forming of the coated stainless strip steel to the desired interconnect shape. The self-healing properties of the coating ensure the same excellent performance of Sanergy HT 441 before and after forming. Any micro cracks introduced to the coating by forming will heal and completely disappear during operation of the fuel cell.

441-type (EN. 1.4509) stainless steel is used as the standard stainless steel for coating. However, other stainless steel grades may be available on request

Main characteristics of Sandvik Sanergy HT 441 coated steel strip steel for SOFC interconnects

  • Good surface conductivity
  • Excellent high-temperature corrosion resistance
  • Well-matched thermal expansion
  • Low electrical degradation
  • Good processing and forming characteristics
  • Minimises chromium evaporation

Fuel cells

Read more about fuel cells and our materials for fuel cells.