For the shortages of explosives used on explosive hardening at present,a new polymer bonded plastic explosive is developed.The explosive hardening experiments on Hadfield steel of rail frogs show that the hardness on the surface of rail frogs can reach from HB170~190 to HB260~280 by hardened one time and to HB310~330 by hardened two times.Hardness measurements of explosive hardening on Hadfiled steel are discussed based on metallography analysis.At last,the explosive hardening is simulated by Ls-dyna,and th...