Sumitomo Metal Industries, Inc.

Nippon Steel & Sumitomo Metal Corporation

Nippon Steel Corporation

Nippon Chemiphar Co., Ltd.

Tomio Yamakawa

Kazuhiro Shimoda

Yuji Inoue

Yasuyoshi Hidaka

Kouji Yamane

Naoya Hirase

Shogo Sakuma

Keishi Matsumoto

Seiichiro Masui

Masaaki Igarashi

Hirokazu Okada

Kouichi Kuroda

Tetsuya Nakanishi

Kenji Takeuchi

Toshihiro Takahashi

Tadashi Kobayashi

Hisashi Amaya

Takashi Kanda

Chihiro Hayashi

Shinichi Yoshida

Hiroyuki Semba

Sumio Iida

Akihiro Yamanaka

Kunio Kobayashi

Masatoshi Ushioda

Kazutaka Asabe

Yasuto Higashida

Atsushi Tendo

Masayuki Sagara

Toshiro Anraku

Kenichi Saitou

Kouji Nakaike

Takahisa Kato

Tsuyoshi Endo

Shuichi Akiyama

Hiroaki Murakami

Koji Muramatsu

Junichi Nishimori

Masayoshi Akiyama

Hirofumi Hori

Katsuya Kondo

Kouji Muramatsu

Kazuki Okai

Rie Takahashi

Nobutaka Mochiduki

Susumu Nihashi

Satoshi Tsuyuguchi

Yoshiyuki Kuroiwa

Yoriko Shinohara

Kouichi Harada

Syusuke Shimooka

Tadashi Douhara

Tsuneo Kondo

Hirotsugu Nakaike

Nobutaka Mochizuki

Yasufumi Kitamura

Manabu Adachi

K Shimoda

There is provided a piercing apparatus in which the occurrence of an inner surface flaw in a hollow shell is suppressed. A piercing apparatus () according to an embodiment of the present invention is the piercing apparatus () which pierces a billet (). The piercing apparatus () has a plug (). The plug () has a through hole (). The through hole () extends along the central axis, and allows the central portion of the billet () being pierced to pass therethrough.

Piercing apparatus, plug used for piercing apparatus, and method for producing seamless steel pipe

An inner surface regulation tool includes a mandrel, a plug which is detachably connected to the mandrel, and a connection member which connects the plug and the mandrel by a magnetic force. One of the plug and the mandrel includes a column-shaped portion which extends in an axial direction of the one, and the other of the plug and the mandrel includes a joining hole which extends in an axial direction of the other and into which the column-shaped portion is inserted. In addition, the connection member is a permanent magnet which is attached to at least one of the column-shaped portion and the joining hole.

Inner surface regulation tool, plug, mandrel, hot rolling mill, press piercing machine, and drawing machine

A method of producing a seamless metal pipe, which can suppress the occurrence of lamination defects, is provided. A method of producing a seamless metal pipe according to an embodiment of the present invention includes the steps of: heating a high alloy containing, by mass %, Cr: 20 to 30% and Ni: more than 22% and not more than 60% in a first heating furnace (S2); piercing-rolling the high alloy heated in the first heating furnace with a first piercing machine to produce a hollow shell (S3); heating the hollow shell in a second heating furnace (S4); and elongation-rolling the hollow shell heated in the second heating furnace with the first piercing machine or a second piercing machine which is different from the first piercing machine (S5).

Method of producing seamless metal pipe

A plug for hot pipe making includes a plurality of plug pieces which is attachable to and detachable from one another, and a connection member which connects the plug pieces by a magnetic force. One of the plug pieces connected to each other includes a column-shaped portion which extends in an axis direction of the plug for hot pipe making, and the other includes a joining hole which extends in the axis direction of the plug for hot pipe making and into which the column-shaped portion is inserted. The connection member is a permanent magnet which is attached to at least one of the column-shaped portion and the joining hole.

Plug for hot pipe making

By using a piercing mill that includes a pusher on the entrance side, a plug on the exit side along a pass line, and a plurality of angled rolls as being provided around the plug so as face to each other, in the case where the maximum diameter of an unsound region consisting of center segregation and porosity in a cross section of a billet is d [mm], piercing-rolling is performed under the condition that the plug nose rolling reduction ratio (TDF) expressed by Formula (1) satisfies Formula (2).=(Bd&#x2212;1)/Bd&#x2003;&#x2003;(1)&#x2266;&#x2212;0.50&#xd7;(/Bd)+0.06&#x2003;&#x2003;(2)In Formulae (1) and (2), Bd is the billet diameter [mm], and Dis the opening [mm] between the angled rolls at the plug nose position. Thereby, when piercing-rolling is performed, the occurrence of an inner surface flaw attributable to the center segregation and porosity in the billet can be prevented reliably.

Method for producing seamless tube/pipe

A method of producing a seamless metal pipe, which can suppress the occurrence of inner surface flaws, is provided. A method of producing a seamless metal pipe according to an embodiment of the present invention includes the steps of: heating a high alloy billet BL containing, by mass %, Cr: 20 to 30% and Ni: more than 22% and not more than 60% in a heating furnace F(S); piercing-rolling the high alloy billet BL heated in the heating furnace Fwith a piercing machine Pto produce a hollow shell (S); cooling the hollow shell and then reheating the hollow shell in the heating furnace F(S); and elongation-rolling the heated hollow shell with the piercing machine P(S).

A method for manufacturing an Ni base alloy pipe stock comprises piercing and rolling a billet by use of Mannesmann piercing and rolling mill. The pipe stock has controlled amounts of C, Si, Mn, P, S, Cr, Ni, Mo, W, Cu, Al, N, with the balance being Fe. With the method, the following equations are satisfied, wherein values of T, Pand Prepresented by the following equations (1) to (3) being not more than 1300, not more than 200 and not less than 0, respectively=1380&#x2212;5000P&#x2212;100S&#x2212;4400C&#x2003;&#x2003;(1),Ni+10(Mo+0.5W)+100N&#x2003;&#x2003;(2),=(Ni&#x2212;50)+10(N&#x2212;0.1)&#x2212;2(Cr&#x2212;25)&#x2212;5(Mo+0.5W&#x2212;6)+12&#x2003;&#x2003;(3),wherein each element symbol in the equations represents mass % of the element concerned.

Method for manufacturing Ni base alloy pipe stock

The present invention provides a lubricant composition for hot metal working which is capable of inhibiting generation of flaws on the surface of materials to be provided for hot metal working, and provides a method of hot metal working. The invention provides a lubricant composition for hot metal working comprising a plurality of glass frits respectively having different softening point from each other.

Lubricant composition for hot metal working and method of hot metal working using the same

There is provided an antioxidant agent capable of preventing scale from being produced on the surface of a heated metallic starting material more effectively than the conventional antioxidant agent. The antioxidant agent according to the present invention contains a plurality of glass frits having different softening points and an inorganic compound having a melting point not higher than 600&#xb0; C. The inorganic compound mainly softens in the low-temperature range of about 600&#xb0; C. The plurality of glass frits mainly soften in the low-temperature range of about 600 to 1300&#xb0; C. Therefore, the antioxidant agent covers the surface of metallic starting material in a broad temperature range, oxidizes the surface of metallic starting material, and prevents the production of scale.

Antioxidant agent and process for producing metallic material

There is provided an antioxidant agent excellent in anti-dripping property and anti-peeling property. The antioxidant agent in accordance with the present invention contains a plurality of glass frits having different softening points, potter's clay, and bentonite and/or sepiolite. On account of the potter's clay, the antioxidant agent applied to the surface of a metallic starting material is less liable to drip down. Further, on account of the bentonite and/or sepiolite, the antioxidant agent is less liable to peel off the surface of the metallic starting material.

An Fe&#x2014;Ni alloy pipe stock containing, by mass %, C&#x2266;0.04%, Si&#x2266;0.50%, Mn: 0.01 to 6.0%, P&#x2266;0.03%, S&#x2266;0.01%, Cr: 20 to 30%, Ni: 30 to 45%, Mo: 0 to 10%, W: 0 to 20%, with Mo(%)+0.5W(%): more than 1.5% to not more than 10%, Cu: 0.01 to 1.5%, Al&#x2266;0.01% and N: 0.0005 to 0.20%, and the balance being Fe, with 1440&#x2212;6000P&#x2212;100S&#x2212;2000C&#x2267;1300, Ni+10(Mo+0.5W)+100N&#x2266;120, (Ni&#x2212;35)+10(N&#x2212;0.1)&#x2212;2(Cr&#x2212;25)&#x2212;5(Mo+0.5W&#x2212;3)+8&#x2267;0, can be manufactured into a seamless pipe by use of a Mannesmann piercing and rolling mill because of its excellent inner surface properties. The resulting seamless pipe has excellent mechanical properties and moreover has excellent corrosion resistance in a sour gas environment.

Fe-Ni alloy pipe stock and method for manufacturing the same

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

The present invention is to provide a method for producing duplex stainless steel seamless pipe in which a duplex stainless steel billet can be inhibited from generating an oxide scale on the surface thereof during heating and the generation of outer surface flaw can also be prevented. The billet is heated in the a heating furnace for 1.5 hours or more and 4.0 hours or less at a heating temperature of 1250&#xb0; C. or more and 1320&#xb0; C. or less while regulating the average concentration of sulfur dioxide (SO) gas in the atmosphere within the furnace to 0.01 volume % or less.

Method for producing duplex stainless steel seamless pipe

A plug includes a front edge portion having a convex curvature; a cylindrical portion having a truly or nearly cylindrical shape; a trunk portion having an outer diameter gradually increasing toward a rear edge thereof; a mandrel joint provided in a rear edge portion of the plug; a lubricant ejection hole running through the trunk portion from the mandrel joint that opens on the surface of the cylindrical portion; and a coating comprising oxides and Fe that is formed on the base metal surface of each of the front edge portion as well as the trunk portion by arc spraying using an iron wire. In this way, the plug can prevent inner surface flaws from occurring in a hollow blank that is deformed by piercing-rolling, and can extend its life without requiring a long time for making it.

Plug, piercing-rolling mill, and method of producing seamless tube by using the same

Provided is a method for producing a seamless tube, in which after a starting material to be extruded has been heated to a heating temperature T [&#xb0; C.] satisfying the relationship of Formula (1) or Formula (2) depending on the outside diameter d[mm] thereof, the starting material is hot extruded by providing a solid lubricating glass between the starting material to be extruded and a die, whereby a transverse flaw on the outer surface in the top portion of tube can be prevented when hot extrusion is performed by using a starting material for extrusion having low deformability at high temperatures. When d&#x3c;200, T&#x2266;1250+1.1487&#xd7;A&#x2212;7.838&#xd7;ln(t/t)&#x2212;10.135&#xd7;ln(d/d) . . . (1); when d&#x2267;200, T&#x2266;1219+1.1487&#xd7;A&#x2212;7.838&#xd7;ln(t/t)&#x2212;10.135&#xd7;ln(d/d) . . . (2), where A=L/V&#xd7;1000 [msec.]. V=(V+V&#xd7;&#x3c1;)/2 [mm/sec], &#x3c1;=(t&#xd7;(d&#x2212;t))/(t&#xd7;(d&#x2212;t)), t: wall thickness of starting material to be extruded [mm], d: outside diameter of extruded tube [mm], t: wall thickness thereof [mm], L: length of approach portion of die along extrusion direction [mm], and V: ram speed [mm/sec].

Method for producing seamless tubes

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Osaka, Japan

Tomio Yamakawa