The　solidification　microstructure　of　Fe-Cr-B　alloy　containing　1.5%　B,　3%　Cr　and　0.3%　C　was　analyzed,　and　the　effects　of　quenching　temperature　and　cooling　rate　on　microstruture　and　hardness　of　the　alloy　were　investigated.　The　results　show　that　the　microstructure　of　as-cast　Fe-Cr-B　alloy　is　composed　of　pearlite,　ferrite,　eutectic　boride　and　secondary　borocarbide.　After　quenching,　the　matrix　of　alloy　transforms　to　lath　martensite,　and　the　type　of　boride　has　no　any　change.　Quenched　at　900-1100,　the　hardness　firstly　increases　and　then　decreases,　while　the　phenomenon　of　network　breaking　become　more　and　more　bovious.　Compared　with　the　water-cooling,　the　boride　is　smaller　after　oil-cooling.　It　reduces　the　ability　of　crack　propagation.　©,　2014,　Editorial　Office　of　Transactions　of　Materials　and　Heat　Treatment.　All　right　reserved.