The　effects　of　quenching　temperature　on　microstructure　and　hardness　of　cast　Fe-8Cr-2B　alloy　containing　0.3　wt%　C,　2.0　wt%　B,　8.0　wt%　Cr,　0.6　wt%　Si,　and　0.8　wt%　Mn　were　investigated　by　optical　microscopy　(OM),　scanning　electron　microscopy　(SEM),　X-ray　diffraction　(XRD),　Rockwell　hardness　and　Vickers　microhardness　testers.　The　experimental　results　indicate　that　the　as-cast　microstructure　of　cast　Fe-8Cr-2B　alloy　consists　of　M2B　(M　=　Fe,　Cr),　M-7(C,　B)(3),　alpha-Fe,　and　gamma-Fe.　The　dendritic　matrix　composed　of　lath　martensite　mixed　with　a　small　amount　of　retained　austenite,　and　the　netlike　boride　M2B　distribute　in　the　grain　boundary.　After　quenching　between　950　degrees　C　and　1100　degrees　C,　the　netlike　eutectic　boride　are　broken　up　and　a　new　phase-M-23(C,　B)(6)　which　is　distributed　in　the　shape　of　sphere　or　short　rod-like　are　precipitated　from　the　matrix.　Both　the　macrohardness　and　microhardness　of　specimens　increase　with　the　increasing　quenching　temperature.　At　about　1050　degrees　C,　the　hardness　reaches　the　maximum　value.　However,　when　the　temperature　exceeds　1050　degrees　C,　the　hardness　will　decrease　slightly.　With　the　increase　of　tempering　temperature,　the　hardness　of　cast　Fe-8Cr-2B　alloy　quenching　from　1050　degrees　C　decreases　gradually　and　its　impact　toughness　increases　slightly.　Crusher　hammer　made　of　cast　Fe-8Cr-2B　alloy　quenching　from　1050　degrees　C　and　tempering　from　300　degrees　C　has　good　application　effect,　and　its　service　life　improves　by　150-180%　than　that　of　high　manganese　steel　hammer.