英文摘要: GCr15 steel was investigated for replacing high-speed steel (HSS) and 18Cr2Ni4W steel used in oil nozzle assembly.A new method of heat treatment,bright hardening,was employed to improve the properties of GCr15 steel.The results show that the hardness and bending strength is slightly lower and the values of aK and KIC are higher by 60% and 65% respectively than that of HSS.The service life of GCr15 steel oil nozzle assembly is more than 2000 hours.The GCr15 steel is fully satisfied the using requirement,and its cost is reduced greatly comparing with HSS.