Study On Explosion Hardening Technology Of Hadifield Steel

Rail-switches are key parts of rail structure and necessary line facility by which trains can change routes. Master parts of rail-switches wear severely with the pick up speed of trains. We try to seek a new production method and processing technique to raise wear-resistant property of switches. For many years the people have conceived, if can before the high-manganese steel casting use forms one in the steel surface to have certain degree of hardness and the depth hardened level, then the high-manganese steel casting's resistance to wear may enhance inevitably. After the high-manganese steel distorts, degree of hardness is very high moreover the request hardening level to be quite thick, is unable with the general production work hardening's method to form. But the explosion hardening can actually affects within the extremely short time by the huge energy and the pressure to the steel surface, causes its hardening, achieves the operation requirements.Hadifield steel was treated with explosion hardening, then we analyzed its structure, property and put forward the microcosmic mechanism of explosion hardening for hadifield steel. Divides the effects which to the homogeneous blasting explosive same dose two detonations and one time explode to carry on the comparison, discovered that uses two detonations compared to an detonation, regardless of the surface strength hardens the depth to have the obvious improvement. The impact abrasive wear properties of exploded hadifield steel and unexploded hadifield steel were studied. The results show that with soft abrasive materials of glass sand, the impact wear-resistant of high manganese steel with explosion hardening increases 20%～38%. With high hardness abrasive materials of cobble, the impact wear-resistant of high manganese steel with explosion hardening increases 43%～56% when impact energy was less than 1.7 J. When impact energy was beyond 1.7 J, the explosion hardening decreases the impact wear-resistant of high manganese steel. The main reason for the change of impact wear-resistant of high manganese steel is that its superficial coat hardness and dynamic ductility are sharply changed by explosion hardening. The appropriate work condition of explosion hardening high manganese steel is soft abrasive materials with high impact energy and high hardness abrasive materials with low impact energy.