MILLING CUTTER TOOL FOR ASPHALT STRIPPING, WITH WEAR-PROOF PROTECTION AND SELF-BLOCKING PROTECTION UPON ROTATION AND PROCESS FOR MANUFACTURING THE SAME

摘要

The invention relates to a milling cutter tool for asphalt stripping, of the composite cone type, equipped with two systems of self-protection, one against wear and the other against self-blocking. According to the invention, the tool consists of a tool support () which is consolidated at the conical surface level with the system () of self-blocking when rotated about its own axis, system which, in its turn, consists of a matrix of steel low-alloyed with Cr, with the dimensions of 10 x 2.5 mm, and wherein there are embedded particles of melted W carbide, with crushing texture in the granulometric class of 3 mm, and a reinforced cutting body () made of W carbides sintered and consolidated at the active surface level with the system made of grids with a depth of at least 1.5 mm. As claimed by the invention, the process has a preparing stage in which the semi-finished tool support () is made, with the shank for fixing into the mill body, by cutting and hot-forging at temperatures ranging between 850...1050°, the hardening of the tool support () by thermal hardening treatments in oil at 860...900°C and tempering at 480...420°C for two hours, finishing the tool support () at dimensions of brazing in capillary joint and sliding borehole, carrying out, by W carbides sintering, the cutting body () reinforced with tolerance of sliding borehole with clearance suitable to brazing in capillary joint, carrying out the system () of self-protection against wear by creating, with laser beam or electron beam, some grids on a depth of 1.5 mm, the brazing in the tool support () of the cutting body () reinforced, at 700°C, carrying out the system () of protection against self-blocking by flame melting the tubular rods of "relit" type at a pre-heating temperature, between rows, of 400°C, at the most, and obtaining the layer with a size of 10 x 2.5 mm, followed, in the end, by the slow cooling of the tool-mill assembly at a cooling rate of 50°C/h, at the most, in sand previously heated to 60°C.