Drill resistant hard plate and method for manufacture thereof
OwnerJ. Clayton Miller, Kevin Rafferty +1inventors
InventorsJ. Clayton Miller, Kevin Rafferty, Leonard Wetz
Life of this patent
Estimating the term…
Abstract
A highly drill-resistant element, suitable for inclusion into the walls and/or doors of a security container to resist drilling to access the contents of the container is formed by welding onto a steel plate formed of REPUBLIC 100-AR (TM) steel a layer of Tube BORIUM.RTM. material by a known tungsten-inert-gas (TIG welding process). The REPUBLIC 100-AR (TM) steel has a chemical composition and is manufactured to inherently possess a very high yield strength and abrasion resistance. The Tube BORIUM.RTM. material, welded by the thick process, provides a very hard and drill-resistant layer comprising a heterogenous suspension of tungsten carbide particles of selected size in a steel matrix.
Claims9
A process for manufacturing a hard drill-resistant element, comprising the step of:
- (a) providing a filler material comprising a steel tube having 5-40 mesh tungsten carbide particles therein;
- (b) providing a steel plate;
- and
- (c) forming a layer of said tungsten carbide particles suspended in a steel matrix on said steel plate by welding said filler material using tungsten inert gas welding conditions, said layer having a compositional gradient of tungsten carbide particles from an outer surface of said layer to said steel plate, such that said tungsten carbide particles are concentrated in said layer at a location removed from said outer surface to provide said drill resistance.
A drill-resistant hard plate for a security container, comprising:
- a steel plate having a weld-receiving surface;
- and a drill-resistant layer comprising tungsten carbide particles ranging from 5 to 40 mesh suspended in a steel matrix, welded to said weld-receiving surface by tungsten-inert-gas welding, said layer having a compositional gradient of tungsten carbide particles from an outer surface of said layer to said steel plate, such that said tungsten carbide particles are concentrated in said layer at a location removed from said outer surface to provide said drill resistance, said welding forming said drill resistant plate with a generally flat upper surface, wherein said tungsten-inert-gas welding further comprises the steps of providing a filler material comprising a steel tube having 5-40 mesh tungsten carbide particles therein and forming said drill resistant layer on said steel plate by welding said filler material using tungsten-inert-gas welding conditions.
A drill-resistant hard plate element for a security container, comprising:
- a steel plate having a weld-receiving surface;
- and a drill-resistant layer comprising tungsten carbide particles ranging from 5 to 40 mesh suspended in a steel matrix, welded to said weld-receiving surface by tungsten-inert-gas welding, said layer having a compositional gradient of tungsten carbide particles from an outer surface of said layer to said steel plate, such that said tungsten carbide particles are concentrated in said layer at a location removed from said outer surface to provide said drill resistance said welding forming said drill resisted plate with a generally flat upper surface,
- wherein, upon completion of said tungsten-inert-gas welding, the plate is further processed by placing the plate in sand for a minimum of one hour of slow cooling to prevent formation of cracks more than about 0.01 in. wide or warpage of more than about 0.06 in. per side, as measured with the plate in a unloaded state with said welded-on layer uppermost.
Dependencies are inferred from the claim text.