Through　the　chemical　analysis,　mechanical　properties　tests,　metallographic　analysis,　fracture　and　fatigue　tests　on　22Cr2Ni4MoVA　steel　cut　from　deactivated　crystal　kettle　which　had　been　used　for　9　years,　we　obtained　a　variety　of　mechanical　properties　data,　and　confirmed　that　the　yield　strength　and　ultimate　strength　of　22Cr2Ni4MoVA　steel　were　basically　unchanged　in　crystal　growing　environment,　but　the　impact　energy,　sectional　shrinkage　and　fracture　toughness　that　reflect　material　toughness　were　significantly　descend,　and　there　existed　serious　embrittlement　and　creep　deformation.　The　failure　mode　of　22Cr2Ni4MoVA　steel　was　brittle　fracture　under　the　co-activation　of　creep　fatigue　and　corrosion.　The　decline　of　creep　deformation　and　endurance　limit　at　high　temperature　played　a　guiding　role;　fatigue　and　corrosion　played　an　initiative　attacking　role;　and　temper　brittleness　acted　in　degenerating,　losing　immunity　and　increasing　crack　sensitivity;　while　the　stress　concentration　on　kettle　bottom　and　alkaline　solution　with　high　concentration　provided　a　breeding　ground　for　failure.　©　(2012)　Trans　Tech　Publications.