Cost Effective FeCrAl Alloys by Roll-Bonding and In- Situ Diffusion Alloying for Catalytic Converters Used for Exhaust Gas Emission Control

摘要

High Cr, high Al ferritic FeCrAl alloys have been used in catalyst converters to replace ceramic substrate. Metal substrate catalyst converter has several advantages over ceramic substrate one. However, the cost has also to be considered in a design formula between metal and ceramic substrates, whereas the final cost of a finished unit is not always favorable to one or another. This paper describes a cost effective manufacturing method of metal substrate catalytic converter. In this proprietary method, a sandwiched Al/Fe22Cr/Al composite is first made by roll-bonding and then further processed to a foil thickness. The composite foils are then fabricated to a honeycomb-like converter with air flow channels. The converter is then thermally treated at a high temperature during a necessary converter fabrication process. The monolithic Fe21Cr6Al alloy is then obtained in the converter by in-situ diffusion alloying. The materials properties of the alloy have been evaluated and showed satisfied results. Approach for applications of the method is outlined.