The present invention relates to a wire rod of which softening heat treatment can be omitted, and a manufacturing method therefor. One embodiment of the present invention provides a wire rod of which softening heat treatment can be omitted, and a manufacturing method therefor, the wire rod comprising, by wt %, 0.2-0.45% of C, 0.02-0.4% of Si, 0.3-1.5% of Mn, 0.3-1.5% of Cr, 0.02-0.05% of Al, 0.01-0.5% of Mo, 0.01% or less of N, and the balance of Fe and other inevitable impurities, and having a microstructure consisting of, by area %, 40% or more of proeutectoid ferrite based on an equilibrium phase, 40% or more of regenerated pearlite and bainite, and 20% or less of martensite, and wherein the colony average size of the pearlite in the region amounting to ⅖ to ⅗ of the diameter is 5 μm or less.

The present invention relates to a wire rod of which softening heat treatment can be omitted, and a manufacturing method therefor. One embodiment of the present invention provides a wire rod of which softening heat treatment can be omitted, and a manufacturing method therefor, the wire rod comprising, by wt %, 0.2-0.45% of C, 0.02-0.4% of Si, 0.3-1.5% of Mn, 0.3-1.5% of Cr, 0.02-0.05% of Al, 0.01-0.5% of Mo, 0.01% or less of N, and the balance of Fe and other inevitable impurities, and having a microstructure consisting of, by area %, 40% or more of proeutectoid ferrite based on an equilibrium phase, 40% or more of regenerated pearlite and bainite, and 20% or less of martensite, and wherein the colony average size of the pearlite in the region amounting to ⅖ to ⅗ of the diameter is 5 μm or less.

The production method according to the invention for creating a thread in an elongated semi-finished product comprises the following steps: shaping, especially lengthwise rolling, of at least two lengthwise grooves into a blank and lengthwise rolling of a thread into the areas circumferentially delimited by the grooves. The distance from the beds of the grooves to the axis of the blank is smaller than the distance from the root of the thread to the axis.

A conveyor belt configured for a direction of travel, the conveyor belt including a plurality of connecting rods; and a spiral overlay; wherein each of the connecting rods has a flattened oblong cross section. In addition, a method a manufacturing a connector rod for a conveyor, belt includes providing a connector rod having a circular cross section; rolling the connector rod along a longitudinal axis thereof, and thereby producing a flattened oblong cross section.

A provisional elongation strain difference distribution Δε(x) of a metal strip during rolling is found under conditions in which out-of-plane deformation of the metal strip is restrained. A critical buckling strain difference distribution Δε.sub.cr(x) is found based on the provisional elongation strain difference distribution Δε(x), a strip thickness and strip width of the metal strip, and tension acting on the metal strip at exit from a rolling mill. In cases in which the provisional elongation strain difference distribution Δε(x) exceeds the critical buckling strain difference distribution Δε.sub.cr(x), the difference between the provisional elongation strain difference distribution Δε(x) and the critical buckling strain difference distribution Δε.sub.cr(x) is found, and this difference is added to the provisional elongation strain difference distribution Δε(x) to find a true elongation strain difference distribution Δε′(x). Rolling conditions are set based on the true elongation strain difference distribution Δε′(x), and the metal strip is rolled, thereby controlling the profile of the metal strip.

A provisional elongation strain difference distribution Δε(x) of a metal strip during rolling is found under conditions in which out-of-plane deformation of the metal strip is restrained. A critical buckling strain difference distribution Δε.sub.cr(x) is found based on the provisional elongation strain difference distribution Δε(x), a strip thickness and strip width of the metal strip, and tension acting on the metal strip at exit from a rolling mill. In cases in which the provisional elongation strain difference distribution Δε(x) exceeds the critical buckling strain difference distribution Δε.sub.cr(x), the difference between the provisional elongation strain difference distribution Δε(x) and the critical buckling strain difference distribution Δε.sub.cr(x) is found, and this difference is added to the provisional elongation strain difference distribution Δε(x) to find a true elongation strain difference distribution Δε′(x). Rolling conditions are set based on the true elongation strain difference distribution Δε′(x), and the metal strip is rolled, thereby controlling the profile of the metal strip.

Provided is a rolling straightening machine which enables outer-diameter-reducing rolling and straightening rolling of a pipe or tube material or a bar material at high speed with high accuracy. The rolling straightening machine includes at least two rollers arranged across a pass line of a pipe or tube material or a bar material, the at least two rollers having a gap therebetween, the gap being defined by an outer-diameter-reducing rolling portion having a diameter reduced from an upstream side toward a downstream side in the rolling straightening machine and a straightening rolling portion continuous from an exit side of the outer-diameter-reducing rolling portion toward a downstream side of the rolling straightening machine, the rollers having shapes which are symmetrical about the pass line in the outer-diameter-reducing rolling portion, and in the straightening rolling portion, asymmetrical to the pass line in the outer-diameter-reducing rolling portion.

Provided is a rolling straightening machine which enables outer-diameter-reducing rolling and straightening rolling of a pipe or tube material or a bar material at high speed with high accuracy. The rolling straightening machine includes at least two rollers arranged across a pass line of a pipe or tube material or a bar material, the at least two rollers having a gap therebetween, the gap being defined by an outer-diameter-reducing rolling portion having a diameter reduced from an upstream side toward a downstream side in the rolling straightening machine and a straightening rolling portion continuous from an exit side of the outer-diameter-reducing rolling portion toward a downstream side of the rolling straightening machine, the rollers having shapes which are symmetrical about the pass line in the outer-diameter-reducing rolling portion, and in the straightening rolling portion, asymmetrical to the pass line in the outer-diameter-reducing rolling portion.

Hot rolling stock (1) made of metal which is rolled in at least one roll stand (2) and then cooled in a cooling section (5) arranged downstream of the at least one roll stand (2). Sound generated by means of a sound generator arrangement (8) is coupled into the rolling stock (1) by a coupling device (1) so that a standing sound wave is formed at least in the region of the rolling stock (1) which is located in the vicinity of the coupling device (10).

Hot rolling stock (1) made of metal which is rolled in at least one roll stand (2) and then cooled in a cooling section (5) arranged downstream of the at least one roll stand (2). Sound generated by means of a sound generator arrangement (8) is coupled into the rolling stock (1) by a coupling device (1) so that a standing sound wave is formed at least in the region of the rolling stock (1) which is located in the vicinity of the coupling device (10).