A method for producing a tube of a nickel-based alloy tube which comprises the steps of hot working a nicked-based alloy casting into a pretubular-shaped workpiece or into a cylindrical bar, trepanning the cylindrical bar or machining an inner diameter of the pretubular-shaped workpiece to obtain a tubular workpiece, and cold working the tubular workpiece. The hot working comprises one of: rolling, forging, and a combination thereof. The cold working comprises flow forming or pilgering. A nickel-based alloy tube produced with the method comprises an outer diameter greater than or equal to 60.3 mm, an average wall thickness greater than or equal to 2.8 mm, and less than or equal to 70 mm.
C22F 1/10 - Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of nickel or cobalt or alloys based thereon
C21D 9/14 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articlesFurnaces therefor for tubular bodies or pipes wear-resistant or pressure-resistant pipes
A method for producing a tube of a stainless steel alloy tube which comprises the steps of hot working a stainless steel casting into a pretubular shaped workpiece or into a cylindrical bar, trepanning the cylindrical bar or machining an inner diameter of the pretubular shaped workpiece to obtain a tubular workpiece, and cold working the workpiece. The hot working comprises one of: rolling, forging, and a combination thereof. The cold working comprises flow forming or pilgering. The stainless steel tube produced with the method comprises an outer diameter greater than or equal to 152 mm, an average wall thickness greater than or equal to 2.8 mm and less than or equal to 70 mm, and a length greater than 5 m.
C21D 9/08 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articlesFurnaces therefor for tubular bodies or pipes
C21D 7/12 - Modifying the physical properties of iron or steel by deformation by cold working of the whole cross-section, e.g. of concrete reinforcing bars by expanding tubular bodies
B21C 37/00 - Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided forManufacture of tubes of special shape
B21B 1/00 - Metal rolling methods or mills for making semi-finished products of solid or profiled cross-sectionSequence of operations in milling trainsLayout of rolling-mill plant, e.g. grouping of standsSuccession of passes or of sectional pass alternations
B21B 17/06 - Tube-rolling by rollers of which the axes are arranged essentially perpendicular to the axis of the work, e.g. "axial" tube-rolling with mandrel in a discontinuous process
B21B 19/00 - Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work
3.
NICKEL-BASED ALLOY TUBES AND METHOD FOR PRODUCTION THEREOF
A method for producing a tube of a nickel-based alloy tube which comprises the steps of hot working a nicked-based alloy casting into a pretubular-shaped workpiece or into a cylindrical bar, trepanning the cylindrical bar or machining an inner diameter of the pretubular-shaped workpiece to obtain a tubular workpiece, and cold working the tubular workpiece. The hot working comprises one of: rolling, forging, and a combination thereof. The cold working comprises flow forming or pilgering. A nickel-based alloy tube produced with the method comprises an outer diameter greater than or equal to 60.3 mm, an average wall thickness greater than or equal to 2.8 mm, and less than or equal to 70 mm.
C21D 8/10 - Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
C21D 9/14 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articlesFurnaces therefor for tubular bodies or pipes wear-resistant or pressure-resistant pipes
4.
Method for bending tubular articles with a relative ratio of the bending radius and the outer diameter of the finished pipe which is less than 3
Method for bending tubular articles with a relative ratio of the bending radius (R) and the outer diameter (D) of the finished pipe which is less than 3, comprising the following steps: forging an article made of material with a predefined composition depending on the final use and with a predefined length (L) in the longitudinal direction and an outer diameter (D); providing a die having an asymmetrical bottom die half with seat for the pipe; and a top die half with punch asymmetrically arranged in the longitudinal direction (X-X) with respect to the vertical center axis of the die; heating the article in an oven to the required temperature for forging depending on the specific composition of the material; positioning the article inside the bottom die half in the longitudinal direction; closing of the two die halves so as to start bending of the article; opening the die; and extracting the bent article.
