PRODUCTION OF TAPERED LONG-LENGTH METAL ARTICLES BY HOT ROLLING Russian patent published in 2015 - IPC B21B21/00 

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Forged blanks, continuously cast blanks or ESR ingots-blanks are heated to ductility temperature. First, said ingots are pierced at helical rolling stand. Sleeves are rolled at Pilger mills to thick-wall pipe billets at the mandrel with turn over through 90 degrees at rolls with variable round pass. Pipe billets are heated to ductility temperature and rolled at PRU with Pilger mills at mandrels at rolls with pass coiling to roll axis. Axes of rolls are arranged in parallel in vertical plane. Semi-pass of top roll features LH direction of helix line while that of bottom roll has RH direction, or visa versa. The number of turns is defined subject to metal article length and Pilger mill roll body diameter. Sleeves are rolled at long mandrels of periodical taper at three or 3+n Pilger mills arranged in one line. Passes and roll body diameters of every next mill are decrease while their sizes are defined with allowance for invariable path of metal article rolling-out by every Pilger mill.

EFFECT: higher quality of rolled metal articles.

2 cl, 1 dwg, 1 tbl