Process for producing and processing alloyed casting material for working area of indefinite chill rolls, casting material and composite indefinite chill roll incorporating the casting material

摘要

In the present invention, there is disclosed a process for the production and processing of alloyed casting material for a working area of an indefinite chill roll incorporating the casting material containing the following elements: carbon, silicon manganese, chromium, nickel, molybdenum, vanadium and optionally other elements of the 5th group of the Periodic Table of Elements, aluminium wherein the remainder being iron, accompanying elements and impurities related to the manufacturing process. The invented production process comprises the following: (A) providing a melt of the following composition: 2.0 to 3.5 percent by weight of carbon, 1.0 to 2.0 percent by weight of silicon 0.5 to 2.0 percent by weight of manganese, 1.0 to 3.0 percent by weight of chromium 3.5 to 4.9 percent by weight of nickel, 0.20 to 2.9 percent by weight of molybdenum, with the remainder being iron and impurities and (B) more than 0.5 percent by weight and up to 5.9 percent by weight of vanadium is added and dissolved in this composition and (C) the composition of the melt is adjusted by alloy-technological means, by determining the concentrations of carbon, silicon, nickel and the effective sum of the carbide-forming elements, in such a way that when it hardens, the microstructure that forms has 1.0 to 3.0 percent by volume of graphite, on the condition that there are more than 20 graphite particles per mme2 of observation surface of a metallographic section and that the remainder consists essentially of martensite, 8 to 35 percent by volume of eutectic carbides and at least 1 percent by volume of finely divided vanadium carbides, (D) the melt then being cast into a mold, particularly into a continuous casting chill-mold, and allowed to harden into a body, particularly a roll working body and the cast body can be further formed, particularly to a composite roll, wherein the body, respectively the roll so performed (E) can be subjected to a heat treatment consisting in at least one-time heating to a processing temperature, maintaining this temperature and cooling to a room temperature. There is also disclosed a casting material produced in the above-described manner and a composite roll manufactured from the casting material of indefinite structure.