A　reliable　method　to　determine　the　elastic　and　the　plastic　material　constants　is　developed　for　the　refractory lining　material．The　method　conducts　an　experimental-analytical　hybrid　type　inverse　analysis　with　the　use　of　an elastoplastic　finite　element　procedure，on　a　three　point　bend　test　under　operating temperature　conditions．　The material　coefficients　associated　with　the　Ramberg-Osgood　relation　for　the　work　hardening　law　were　determined during　the　loading－unloading　test． 　The　obtained　material　coefficients　were　used　in　a　thermoplastic　analysis　of　the　ladle　lining　material　subjected to　a　cyclic　thermal　shock　simulating　the　operating　conditions、The　finite　element　analysis　accounts　for　the　effects of　the　spinel　reaction　occurring　in　the　material　during　the　heat　cycle　history，as　well　as　for　the　elastoplastic effects．A　significant　degree　of　high　tensile　stress　is　observed　within 50 mm　from　the　surface　in　the　period　of cooling　cycles　of　the　analysis．In　addition，the　spinel　reaction　expansion　further　enhanced　the　stress　level　in　the surface　area，where　a　very　high　temperature　is　experienced　during　the　cycle． Such　localized　high　stress　may promotes　cummulation　of　the　thermal　fatigue　damage，and　therefore　is　considered　to　be　partially　responsible　for the　cause　of　a　possible　delamination　occurring　in　the　ladle　material．

View full abstract