Sumitomo Metal Industries, Inc.

Nippon Steel Sumitomo Metal Corporation

Sanyo Electric Co., Ltd.

Nippon Steel Corporation

Sumitomo Heavy Industries, Ltd.

Ishikawajima-Harima Heavy Industries Co., Ltd.

Kouichi Kuroda

Kazuyuki Nakasuji

Tatsuya Okui

Chihiro Hayashi

Tomio Yamakawa

Takashi Nakashima

Masayoshi Akiyama

Kunio Kondo

Satoshi Matsumoto

Tetsuo Yokoyama

Hajime Suzuki

Tatsuya Hirota

Shigeru Takabe

Masaki Ueyama

Takashi Fukuda

Shigeharu Ochi

Kiyokazu Fujikawa

Kenichi Beppu

Hitoshi Suwabe

Masatoshi Toyoda

Takuya Hanada

Itsushi Iio

Masakatsu Morishige

Naoki Sawawatari

Tsutomu Arita

Satoshi Tsuyuguchi

Yoshiyuki Kuroiwa

Keisuke Nagashima

Nozomu Ariyasu

Katsuji Oonishi

Hisanori Hirose

Tadashi Kawakami

Youichi Imamura

Tamotu Kawamura

Youzou Kawamura

A method for producing a heat transfer tube for a steam generator comprises a step of providing a tube and then applying cold drawing to the tube by using a high-pressure lubricating oil of 40 MPa or more in pressure. After the step of applying cold drawing to the tube, a step of applying a solid solution heat treatment to the tube is conducted. After the step of applying a solid solution heat treatment to the tube, a step of straightening the tube by using a roll straightening machine is conducted. An offset amount of 5 mm or less is formed for at least successive three pairs of upper and lower straightening rolls of the roll straightening machine.

Method for producing a heat transfer tube for steam generator using drawing, solution heat treatment, and straightening

There is provided an austenitic alloy pipe that is durable even if a stress distribution different according to usage environment is applied. The austenitic alloy pipe in accordance with the present invention has a tensile yield strength YSof at least 689.1 MPa. The tensile yield strength YS, a compressive yield strength YSin a pipe axial direction, a tensile yield strength YSin a pipe circumferential direction of the alloy pipe, and a compressive yield strength YSin the pipe circumferential direction satisfy Formulas (1) to (4).0.90&#x2266;&#x2266;1.11&#x2003;&#x2003;(1)0.90&#x2266;&#x2266;1.11&#x2003;&#x2003;(2)0.90&#x2266;&#x2266;1.11&#x2003;&#x2003;(3)0.90&#x2266;&#x2266;1.11&#x2003;&#x2003;(4)

Austenitic alloy pipe and method for producing the same

Provided is a method for producing a double-wall tube with braided wires at its interface in which the braided wires are interposed between an outer-wall and inner-wall blank tubes and then a drawing process is applied so as for the braided wires to be brought into close contact with the inner surface of the outer-wall tube and the outer surface of the inner-wall tube, the method comprising: polishing the inner surface of the outer-wall blank tube and the outer surface of the inner-wall blank tube so that a surface roughness thereof satisfies Ra&#x3c;1.0 &#x3bc;m, followed by interposing the braided wires between the outer-wall and inner-wall blank tubes; performing a sinking drawing process so that the difference of the outer diameter of the resulting double-wall tube relative to a die bore diameter is 0.1 mm to 0.3 mm; and subsequently performing heat treatment. The double-wall tube produced is suitable as a heat-transfer tube.

Method for producing double-wall tube with braided wires at its interface

A method for straightening a tube by using an asymmetric roll, which has different diameters D(exit side), D(entry side) at relative maximum diameter portions, left and right roll shoulder portions, as a straightening roll of a straightener, wherein the roll shoulder having a smaller diameter is disposed to be located on the tube entry side. The straightening roll used therefor comprises roll shouldersandand a roll barrel portion, in which D&#x3e;Dand 0.004&#x2266;(D&#x2212;D)/d&#x2266;0.2 (d: outer diameter of tube to be straightened) are satisfied. Further, an aspect of the invention may define radii of curvatures of entry-side and exit-side shoulder potions in a section of the roll cut along a plane including the roll central axis, or a curve representing an outer surface of the roll barrel portion.

Method for straightening tube and straightening roll

A plugincludes a first columnar portion, a tapered portion, and a second columnar portion. The first columnar portionhas an outside diameter D. The second columnar portionhas an outside diameter Dwhich is larger than the outside diameter D. The tapered portionis formed between the first columnar portionand the second columnar portion. The tapered portionhas a tapered surfaceprovided with an outside diameter which is gradually increased from the first columnar portionto the second columnar portion, and an axial direction length L. The outside diameters Dand D, and the axial direction length L meet the following expressions (1) to (4):0.25&#x2266;&#x3c1;&#x2266;2.00&#x2003;&#x2003;(1),0.06&#x2266;2&#x2266;0.8&#x2003;&#x2003;(2),2&#x2266;0.3&#xd7;&#x3c1;+0.575&#x2003;&#x2003;(3), and2&#x2267;0.1&#xd7;&#x3c1;&#x2003;&#x2003;(4)where &#x3c1;=(2&#x2212;1)/1&#xd7;100.Therefore, the cold drawing plug according to the present invention can reduce the tensile residual stress on the outer surface of a metal pipe after the cold drawing.

Plug for cold drawing and method for manufacturing of metal pipe

The present invention provides an induction-hardened hollow driving shaft that comprises, as a raw material, a steel pipe that contains, by mass %, 0.30 to 0.47% C, 0.5% or less Si, 0.3 to 2.0% Mn, 0.018% or less P, 0.015% or less S, 0.15 to 1.0% Cr, 0.001 to 0.05% Al, 0.005 to 0.05% Ti, 0.004% or less Ca, 0.01% or less N, 0.0005 to 0.005% B and 0.0050% or less O (oxygen) and the balance Fe and impurities and of which Beff defined by an equation (a) or (b) below is 0.0001 or more, wherein a prior austenite grain size number (JIS G0551) after the hardening is 9 or more. Here, in the case of Neff=N&#x2212;14&#xd7;Ti/47.9&#x2267;0, Beff=B&#x2212;10.8&#xd7;(N&#x2212;14&#xd7;Ti/47.9)/14 . . . (a), and, in other cases, Beff=B . . . (b). According to the present invention, a hollow driving shaft that is simultaneously provided with excellent cold workability, hardenability, toughness and torsional fatigue strength and can exert stable fatigue lifetime can be obtained and can be widely utilized.

Induction hardened hollow driving shaft

An apparatus for sizing a pipe end comprising: a plugfor sizing the pipe end; a chuckfor clamping the pipe; and shifting means for shifting the position of the plugand/the chuck, which are placed successively from the end of the pipe, and the plughas a circular cross section, and is constituted by a taper portionand a diameter equivalent portioncontinuously formed from the tip of the plug in succession. The outer diameter of the taper portionis gradually expanding from the tip toward the rear end while satisfying the following formulas (1) and (2). The chuckis capable of changing clamping position of the pipe. This apparatus makes it possible to size the inner diameter of a pipe end with superior dimensional precision/()&#x2266;&#x2003;&#x2003;(1)RR&#x2003;&#x2003;(2).

Apparatus for pipe end sizing and method for pipe end sizing

The present invention provides a mechanical pipe-end expander comprising a cone and a die having tapered wedge bodies whose outer radius is larger towards a flangeless end direction from a flange end, wherein a pipe-end zone is expanded by a wedge effect of the die, which results from a procedure that the cone and the die are inserted together into the pipe-end zone to be expanded, and that then only the cone is axially drawn outwards leaving the die within the pipe-end zone. A seamless steel pipe with an expanded pipe-end zone is manufactured by applying a mechanical pipe-end expander comprising a die having tapered wedge bodies whose outer radius is larger towards a flangeless end direction from a flange end. The resulting seamless steel pipe has satisfactory pipe-end dimensional accuracy, and exhibits characteristics with excellent field welding workability.

Mechanical pipe-end expander and a method of manufacturing seamless steel pipe

In straightening a tube using a roll straightening machine provided with drum type straightening roll pairs vertically opposingly disposed, at least an outer layer portion of a roll main body is made of elastic material having spring type hardness Hs (JIS K 6301 A type) of 50 to 100 in at least three pairs of straightening rolls on an outlet side of the roll straightening machine, and an offset amount is imparted to a tube engaged in the three pairs, at least, of straightening opposing rolls such that &#x3b7; defined by an equation (1) ranges from 1.0&#xd7;10to 1.5&#xd7;10. The offset amount is set at three positions along a tube axis where the upper and lower rolls of each pair horizontally cross. Therefore, an S/N ratio can be enhanced in an eddy current test from inside of the tube to improve inspection efficiency, and excellent quality accuracy can be ensured in a heat transfer tube used in a steam generator and the like. 

Process for straightening a tube

Cold finished seamless steel tubes are made such that the residual stress F to be generated at the stage of the correction process after cold working is controlled to be 30 MPa or more and the scattering thereof is 30 MPa or less, when measured by Crampton method. Further, by adjusting the average grain size of spheroidized carbides, the dimensional change which emerges in lathe turning of the outside and inside diameter of relevant steel tubes due to the residual strain can be suppressed, and the strict roundness as well as the excellent machinability can be secured at the final processing stage of the work pieces for bearing parts. Consequently, steel tubes with high dimensional accuracy and less dimensional change at the final steps such as lathe turning, heat treatment and the like, can be made for use as bearing parts.

Cold finished seamless steel tubes

A process for making a work piece from a &#x3b2;-type titanium alloy material includes subjecting the &#x3b2;-type titanium alloy material to cold working with controlling the reduction rate thereof to vary the reduction rate depending on a position across a plain direction of the &#x3b2;-type titanium alloy material, and then subjecting the &#x3b2;-type titanium alloy material to an aging treatment.

Process for making a work piece from a &#x3b2;-type titanium alloy material

In a method for processing a rotor used for a supercharger and the like, a slanted rolling machine is used having rolls designed such that the rolls are arranged about a pass line along which a material to be molded advances. Each roll is of corn shape and has a plurality of spiral-shaped grooves formed on its side surface. A shaft member made from iron or a similar material is inserted into an aluminum alloy tube. The aluminum alloy tube with the shaft member inside it is continuously fed to the slanted rolling machine along the pass line. Then, the periphery of the aluminum alloy tube is rolled/spread by the rolls for forming spiral shaped teeth from the tube material and for metallurgically attaching the tube to the shaft member.

Method for processing a rotor used for a super charger

The inventive clothes dryer is provided with a system for preventing the overheating of the clothes in the drum caused by the abnormality in the V-belt, such as the break or derailment thereof. By the system, the power supply to the motor is halted temporarily while the motor is rotated at a predetermined speed, whereafter the motor keeps rotating due to its inertia. During the inertial rotation of a predetermined period of time, the number of rotations of the motor is counted. When the V-belt is in the normal state, the motor is loaded appropriately, so that the speed of the motor falls rapidly during the inertial rotation, and the number of rotations is accordingly small. When, on the other hand, the V-belt is in an abnormal state, the number of rotations is large. Therefore, the state of the V-belt is checked by comparing the number of rotations to a predetermined value, and when the number is smaller than the predetermined value, the drying operation is stopped.

Clothes dryer

A method of and an apparatus for rolling a rod as a starting material and producing a wire of 5 mm or smaller diameter, the method and apparatus using a continuous rolling mill comprising a plurality of round-grooved four-roll stands arranged in tandem, wherein the grooved four-roll is displaced between adjacent rolling stands by 45 degrees relative to each other around the pass line and the center-to-center distance between adjacent rolling stands measured in the pass line direction is not greater than 50 times the diameter of the rod. The front end portion of the rod is fed at slow speed into the continuous rolling mill, the front end portion being guided by a front pipe to the center of the round groove, and the front end portion is wound on a coiler. After that, the rotation speed of the grooved rolls in each rolling stand is so set as to prevent slack in the rod passing through the continuous rolling mill, and the rod is rolled at high speed, without causing the rod to touch the leading pipe, to produce a wire. Each of the rolling stands that constitute the continuous rolling mill is movable in a direction perpendicular to the pass line, each rolling stand being moved for connection to or disconnection from the driving source.

Method of and an apparatus for producing wire

According to the rolling method and the apparatus to be used for its execution of the invention, by rolling a tube to be rolled by using four rolls possessing roll grooves for forming a caliber in a shape of having a relief portion, cold reducing or cold stretch reducing is done continuously without causing wall thickness deviation, and by sizing the rolled tube material by a die disposed at the exit side, the dimensional precision and yield of rolled tubes may be enhanced by a small number of stands.

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Takatsuki, Japan

Kouichi Kuroda