초록 ▼

A method for nitriding and nitrocarburizing the bores of rifle barrels or similar elongated hollow objects in which a funnel is attached to the inlet end of each of rifle barrel prior to treatment. The rifle barrels are then loaded into a fluidized bed furnace in a substantially vertical position wi

A method for nitriding and nitrocarburizing the bores of rifle barrels or similar elongated hollow objects in which a funnel is attached to the inlet end of each of rifle barrel prior to treatment. The rifle barrels are then loaded into a fluidized bed furnace in a substantially vertical position with the open end of the funnel facing the direction of flow of the reactant gases and fluidized particulate medium through the fluidized bed furnace. When the rifle barrels are submerged in the fluidized particulate medium, the rifle barrels are heated to a reaction temperature for a predetermined period of time. The funnels increase the quantity of reactant gases and fluidized particulate medium flowing through the bore of each rifle barrel. As a result, excellent nitrided and nitrocarburized surfaces have been obtained in the bores of rifle barrels made from ferrous and titanium alloys at reduced processing temperatures and times.

대표청구항 ▼

A process for hardening the surface of a bore of a rifle barrel comprising the steps of: attaching a funnel to an end of said rifle barrel; disposing said rifle barrel with said attached funnel into a fluidized bed furnace having a particulate medium fluidized by a vertical flow of reactant gases th

A process for hardening the surface of a bore of a rifle barrel comprising the steps of: attaching a funnel to an end of said rifle barrel; disposing said rifle barrel with said attached funnel into a fluidized bed furnace having a particulate medium fluidized by a vertical flow of reactant gases therethrough, said rifle barrel being disposed in a vertical position with said funnel facing in the direction of flow of said reactant gases; and treating said rifle barrel in said fluidized bed with said reactant gases at a predetermined temperature for a predetermined period of time to harden said surface of said bore, said funnel directing an increased amount of said reactant gases and said fluidized particulate medium through said bore of said rifle barrel.