The Performance And Preparation Of Co Coating By Pack-cementaton For SOFC Interconnect

As a clean energy conversion device,Solid Oxide Fuel Cell(SOFC)has great application potential in power generation,transportation,civil and military fields.Connecting as plate type one of the important parts of SOFC,rise to connect the single battery,fuel gas and oxygen to the cathode and anode of the battery,the cost of SOFC pile to about 30%of the total cost,to reduce the temperature SOFC work,to develop the 600??800? in the medium temperature SOFC background,using alloy material to make connecting possible.In order to improve the long-term oxidation resistance and electrical conductivity of high Cr stainless steel connector at high temperature,the Co permeation layer was prepared on the substrate surface by solid powder embedding method.A series of Co-containing compound modified layers were prepared on AISI 430 stainless steel matrix by means of solid powder embedding method with variable technological parameters(holding time,catalyst content).Out the optimum process parameters were optimized for 150?×1 h+800?×2 h,catalyst(NH4CI)content in the impregnation agent for 2 wt.%.The thickness of the permeable layer was about 15?m,which was a mixture of Co,Co3Fe7,Co2FeO4 and Cr2O3 phases.Samples of the preparation of 650 h at 800? in air oxidation,the oxidation weight is parabolic curve.After oxidation,Co elements in the carbonitriding layer gradually transformed into CoFe2O4 of spinel structure and CoCr2O4,carbonitriding layer still contains a small amount of Cr203 at the same time,the oxidized by 800? after 450 h,than are special resistance(ASR)value of 108.32 m?·cm2.In order to reduce the influence of oxygen during the preparation of modified layer,with 150? under argon atmosphere protection 150?×1 h+800?×2 h process preparation Co carbonitriding layer of uniform density,thickness of about 10 microns,main phase permeability layer for Co and a small amount of CoFe2O4 the permeability after oxidation layer generated on the surface of dense CoFe2O4 spinel,and EDS Cr element does not spread to the surface of carbonitriding layer,mainly at the interface between permeability layer-matrix.Under the 800? for 650 h in air oxidation,its weight gain curve is parabolic,after 450 h oxidation,ASR value of 72.68 m?·cm2.Also in argon atmosphere,first through the process 150 0Cx 1 h+800?× 2 h,again through the process 150?×1 h+800 0Cx 3 h,preparation of Co-Mn double permeability layer,thickness of 13?m,its organizational structure by the outer layer of rich Mn(8 microns)and the inner layers of rich Co(5 microns),after the high temperature oxidation experiment and ASR test,found that the various performance compared with argon gas permeability Co and no improvement.