In　this　article,　the　effect　of　heat　treatment　in　different　quenching　temperature　on　microstructure　and　hardness　of　Fe-Cr-B　alloy　was　studied,　by　contrast　with　boron-free　Fe-Cr　alloy.　The　results　indicated　that　microstructure　of　boron-free　Fe-Cr　alloy　consisted　of　the　martensite　and　a　few　(Cr,　Fe)7C3　type　carbide.　The　microstructures　had　no　obvious　change　with　the　increase　of　quenching　temperature,　but　its　hardness　increased　from　51.5　HRC　to　60.8　HRC.　When　boron　element　was　added　into　the　Fe-Cr　alloy,　the　netlike　eutectic　structure　began　to　break　and　spheroidizing　after　quenching,　in　which　the　borocarbide　turned　into　spherical　groups　and　network　Fe2B　phase　was　broken.　Moreover,　the　portion　of　martensite　increased,　and　the　amount　of　secondary　carbide　decreased,　and　the　size　of　secondary　carbide　began　to　largen　after　quenching.　When　the　quenching　temperature　reached　1100　degrees　C,　secondary　carbide　particles　dissolved　in　the　matrix　wholly.　The　hardness　of　Fe-Cr-B　alloy　increased　with　the　increase　of　quenching　temperature　below　1050　degrees　C.　The　hardness　of　sample　containing　2.0%　B　and　quenching　at　1050　degrees　C　reached　66.7　HRC.　The　hardness　of　Fe-Cr-B　alloy　had　no　obvious　change　when　quenching　temperature　continued　to　increase.　After　tempered　at　200　degrees　C,　the　microstructure　of　Fe-Cr-B　alloy　had　no　significant　change　and　its　hardness　had　slight　decrease.　The　hardness　of　sample　containing　2.0%　B　tempered　at　200　degrees　C　reached　63.9　HRC.