Method of manufacturing wire
(57) Abstract:The invention relates to metallurgy, in particular to the technology of wire from nodular cast iron, which combines high strength and plastic properties with resistance against corrosion. The method includes heating rods made of nodular cast iron, multi-pass rotary forging, followed by multi-pass wire drawing and annealing. The rods are heated to a temperature of 800-900oC. Carry out their multi-pass rotary forging with hood for the passage of 1,10-1,52, multipass drawing with hood for the passage 1,08-1,45 at a temperature of 500-700oC and annealing. The wire annealing is carried out at a temperature of 800-1000oC and holding time of 0.5-36 hours the Invention improves the strength, ductility and corrosion resistance of the wire. 1 C.p. f-crystals, 2 tab. The invention relates to metallurgy, in particular to the technology of wire from nodular cast iron (chshg), which combines high mechanical properties with good resistance against corrosion.A known method for the production of wire drawing rods .The disadvantage of this method is low strength, ductility and corrosion actinote and corrosion resistance of the wire.The specified technical task is solved in that the wire is made from nodular cast iron, while the rods are heated to a temperature of 800-900oC, carry out multi-pass rotary forging with hood for the passage of 1,10-1,52, multipass drawing with hood for the passage 1,08-1,45 at a temperature of 500-700oC and annealing.A possible embodiment of the method, according to which the annealing is carried out by heating the wire from chshg to a temperature of 800-1000oC, which was incubated for 0.5 to 36 hoursThe essence of the invention consists in the following. In the process of rotary forging rods chshg at a temperature of 800-900oC in each of the passages is high-cycle deformation of the metal matrix in the austenitic state and graphite nodules with simultaneous recrystallization crushed grains of austenite. When the hood for the passageto= 1,10-1,52 occur in chshg embryonic cracks do not reach the irreversible development and within mergeformatinet pause completely disappear. Because grinding grain microstructure and recrystallization of cold-worked austenite rod from chshg gets higher mechanical properties and technological plastic is the temperature of 500-700oC and the hood for the passage 1,08-1,45 globular particles of graphite inclusions in the beginning acquire an elongated shape, being extended in the direction of drawing, and then break into separate parts that are also close to globular, but with a smaller diameter. That is, after each passage of warm drawing with hoodin= 1,08-1,45 at a temperature of 500-700oC cast iron retains a spherical shape graphite inclusions and high technological plasticity. Metal matrix at these temperatures is softened only partially, so gradually the microstructure of the wire becomes fibrous nature and anisotropy of mechanical properties.Annealing wire obtained from chshg at 800-1000oC for 0.5 - 36 h leads to recrystallization and stabilization of the microstructure, globalizatsii graphite inclusions, increase strength, ductility, corrosion resistance and uniformity of properties.It is found experimentally that if the temperature of the heating rotary forging below 800oC or hood for the passagetoexceeds 1,52, forged rod will be retained and accumulate microcracks, which drastically reduces its mechanical and corrosion properties, do not C leads to grain growth microstructure, deterioration of mechanical properties and reduction hood for the passage of less than 1,10 affects the study of the microstructure chshg and requires an increase in the required number of passes, which is impractical.When the drawing temperature below 500oC or hood for the passageinmore 1,45 strain wire structure of chshg uneven affected by defects, and after annealing has a low mechanical properties and resistance against corrosion. The temperature increase drawing more than 700oC leads to a weakening of the grain boundaries and breakage of the wire during drawing, as well as to the formation of an inhomogeneous microstructure, which reduces mechanical and corrosion properties of the wire. Reduction hood for the passageinless 1,08 does not improve the properties of the finished wire from chshg, and only increases the required number of passes and extend the production cycle.When the annealing temperature is less than 800oC or the time of annealing is less than 0.5 h recrystallization and graphitization chshg proceeds incompletely. The result is not achieved the best complex of mechanical properties and maximum corrosion resistance wire from it. Increasing the annealing temperature of more than 1000oC or the exposure time of more than 36 what s the implementation of the method.Rod of circular cross section with a diameter 10,69 mm from chshg, containing by weight to 3.0% carbon, 1.6% silicon, 0.5% Nickel, modified by cerium and calcium, heated to forging temperature Tto=850oC and set on forging in a rotary forging machine-202, where are forging for 5 passes with hood to= 1,31 in each pass through the following route: Wrought iron rod with a diameter of 5,44 mm crack jokes and ask the pointed end in the chain drawing camp, where before Molokai installed a communicating tube furnace. In the furnace of the rod is heated to a temperature warm lug Tin=600oC and subjected to drawing with technological grease for 5 passes with the hood in each passin= 1,27 route:
After drawing the wire from chshg diameter of 3.00 mm is subjected to high temperature annealing regime: heating to the annealing temperature Tabout=900oC, holding at temperature annealing = 18 h, cooled to room temperature.Finished wire chshg has high strength, ductility and corrosion resistance.In table. 1 shows the options for implementation of the proposed method, and table. 2 - indicators of their effectiveness.As follows from the table. 1 and 2, the ionic resistance of the wire from chshg. In cases of transcendent values of the declared options (options 1 and 5) complex of mechanical properties and corrosion resistance of iron wire deteriorate. 1. Method of manufacturing wire, wherein the wire is made from nodular cast iron, while the rods are heated to a temperature of 800-900oC, carry out multi-pass rotary forging with hood for the passage of 1,10-1,52, multipass drawing with hood for the passage 1,08-1,45 at a temperature of 500-700oC and annealing.2. The method according to p. 1, characterized in that the annealing is carried out by heating to a temperature of 800-1000°C and holding at this temperature for 0.5-36 hours
FIELD: manufacture of drawn products.
SUBSTANCE: drawing machine includes frame and pulling unit for drawing elongated material through drawing tool. Pulling unit includes at least one pulling carriage with drive device. The last includes at least two drives in the form of linear motors having power supplied primary and secondary parts. Frame of machine includes guide passing in drawing direction for respective pulling carriage being part of drives in the form of linear motors. Said guide includes first upper part and second lower part; both parts of guide are arranged obliquely in machine frame and they are turned one to other. Respective carriages move in interval between parts of guide turned one to other. Parts of guide may be arranged in frame along diagonal, X-like or star-like. In variant of invention drawing machine includes movable parts of guide joined by means of carriage with connection members mutually shifted on adjacent carriages.
EFFECT: improved design due to enhanced compactness and flexible motion of carriages.
18 cl, 4 dwg