A Study On The Strengthen Reason Of Certain Big Gun Tube Material

Aimed at import certain big gun tube material which request it'sshoot life is 6000,At present in our country big gun tube material isPCrNi3- MoVA, 32Cr2MolVA ect, shoot life can't reach request.Doresearch on 25Cr3Mo3NiNbZr in all aspect.We hope to develop a big guntube mate- rial which can request the big gun's shoot life, and do athorough research on it's strengthen reseon,material parameter, technicscapability ect. It is found that that the addition of Nb has hindering effectson the growth of prior austenite grains at high temperature, The austenitegrains pronou- ncedly grow only at austenitizing temperature of over1100℃, With the increase of austenitizing temperature, resulting from thecontradictow effects of the gradual dissolution of carbides and theaustenite grain growth, the strength and hardness of the steel increse, atthe same time we found that 25Cr3Mo3NiNbZr is a secondary hardeningsteel,With the increase of tempering temperature, four kinds ofcarbides,i.e.ε,M₃C,M₂C and M7C3,thus improve the elevated—temperature strength of the stee1.Which cause the long life of the big guntube.