Nippon Steel & Sumitomo Metal Corporation

Nippon Steel Corporation

Sumitomo Metal Industries, Inc.

Yasuto Higashida

Yasuyoshi Hidaka

Kazuhiro Shimoda

Tomohiro Yamamoto

Yosuke Tatebayashi

Yuichi Yamanari

Takateru Inage

Yuji Yamamoto

Yoshihiko Hayashi

Tomio Yamakawa

Yuji Inoue

Hideya Kaminaka

Sumio Iida

Kouji Yamane

Kouji Nakaike

Kenichi Saitou

Junko Imamura

Naoya Hirase

Tatsuya Miyai

Naoya Shirasawa

Shusuke Shimooka

Masaharu Nakamori

Ryuutarou Ogata

Jyun Nagakita

Atsushi Nosaka

Fumihito Yoshikawa

Takayuki Aisaka

A piercer plug with increased life and a method of manufacturing it are provided. The piercer plugincludes a tip portionand a trunk portionmade of the same material as the tip portionand continuous to the tip portion. The trunk portionincludes a cylindrical portionhaving a hole used for attaching a bar. The tip portionis harder than the cylindrical portion

Piercer plug and method of manufacturing the same

A piercer plug having good base-material deformation resistance is provided. A method of manufacturing a piercer plug () includes the steps of; preparing a plug body () including a tip portion () and a cylindrical portion () having a hole () usable to attach a bar and located rearward of the tip portion (); forming a build-up layer () on the surface of the tip portion (); and heating the plug body () such that the temperature of the tip portion () with the build-up layer () formed thereon is not lower than the austenite transformation temperature and the temperature of the cylindrical portion () is lower than the austenite transformation temperature.

Method of manufacturing piercer plug

A piercing plug includes a plug main body, and a sprayed coating which is formed on a surface of the plug main body and includes iron and iron oxide. A chemical composition of the sprayed coating includes, in addition to the iron and the iron oxide, by mass %, C: 0.015% to 0.6%, Si: 0.05% to 0.5%, Mn: 0.1% to 1.0%, and Cu: 0 to 0.3%.

Piercing plug and manufacturing method of piercing plug

A piercing plug of the present invention includes: a plug body; a Ni&#x2014;Cr layer formed on a surface of the plug body; and a sprayed coating formed on a surface of the Ni&#x2014;Cr layer. The plug body contains, by mass %, 20 to 30% of Cr, 30 to 55% of Ni, 0.005 to 0.5% of C, 0.1 to 1.0% of Si, 0.2 to 1.5% of Mn, and at least one of Mo and W which satisfy a following conditional expression (A), and remainder including Fe and impurities.1.5%&#x2264;Mo+0.5W&#x2264;8.5%&#x2003;&#x2003;(A)

Piercing plug

Provided is a method for producing a plug for use in a piercing-rolling mill for producing a seamless steel tube/pipe, and the method for producing the plug for piercing-rolling comprises shotblasting a surface of the plug, and arc-spraying a spray wire so as to form a film on a surface of a base metal of the plug that is shotblasted. In the arc-spraying step, the arc spraying is carried out by using, as the spray wire, a cored wire whose iron sheath tube is charged with at least iron oxide particles among iron particles and the iron oxide particles (one or more of FeO particles, FeOparticles, and FeOparticles), so as to form the film containing iron oxide and Fe. Accordingly, it is possible to enhance the production efficiency of the plug, and to produce the plug for piercing-rolling capable of securing the steady enhancement of the durability life of the plug during the piercing-rolling.

Method for producing plug for piercing-rolling

Provided is an equipment system for producing a piercing-rolling plug to be used for producing a seamless steel tube/pipe, which includes a shotblasting device for applying shotblasting on a surface of the plug, and an arc-spraying device for performing arc-spraying of iron wires on a surface of a base metal of the plug to which the shotblasting is applied, so as to form a film containing oxide and Fe thereon. The arc-spraying device includes plural spraying booths each of which separately forms part of the film in turn in each of sections into which the surface of the base metal of the plug is divided along an axial direction of the plug. The production efficiency of the plug can therefore be maintained at a high level, and steady enhancement of the durability life of the plug can be realized during the piercing-rolling.

Equipment system for producing piercing-rolling plug

It is an objective to provide a plug capable of enhancing a usage count of the plug, which is for use in a piercing machine for piercing-rolling a billet, and a regenerating method of the plug. The plug () is for use in a piercing machine () for piercing-rolling a billet (). The plug () includes a body (), a columnar portion (), and a sprayed film (). The body () has a maximum diameter at its rear end. The columnar portion () has the same diameter as the diameter of the rear end of the body (), and extends from the rear end of the body (). The sprayed film () is formed on a surface of the body () and on a surface of the columnar portion ().

Method for regenerating a plug for use in a piercing machine

A plug for hot tube-making includes: a plug main body; a build-up layer formed around an axis of the plug main body on a surface of the plug main body; and a sprayed coating formed on a surface of the build-up layer.

Plug for hot tube-making

To increase the life of a plug used in a piercing machine for piercing-rolling a billet. The plug () is used in a piercing machine () that piercing-rolls a billet (). The plug () includes a plug body (), a build-up layer (), and a sprayed film (). The build-up layer () is formed on a surface of the plug body (). The sprayed film () covers at least an area ranging from the rear end of the build-up layer () to a position of the maximum outer diameter of the plug body ().

Plug used in piercing machine

A stainless steel member comprising a stainless steel base metal; an oxide film located on the surface of the stainless steel base metal; an electroconductive layer located on the surface of the oxide film and comprising a nonmetallic electroconductive material; and an electroconductive material which is located so as to penetrate the oxide film and which electrically contacts the stainless steel base metal and the electroconductive layer is provided as a stainless steel member for a separator of a solid polymer fuel cell having excellent properties such that a degradation in performance is low even after prolonged operation. A solid polymer fuel cell using the stainless steel member is also provided.

Stainless steel material for a separator of a solid polymer fuel cell and a solid polymer fuel cell using the separator

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

A piercing and rolling plug has a film composed of oxides such as FeOand FeO and Fe (metal) as being formed on the surface of the base metal by electric arc spraying using an iron wire whose main component is Fe and, owing to this film, a plug excellent in heat-shielding and seizure-preventing effects can be realized and the lifetime of the plug can be prolonged. Further, in regenerating this plug, a film can be re-formed via the steps of shot blasting of the as-used plug in piercing and rolling and electric arc spraying in that order; thus, it is possible to regenerate the plug at low cost and in a short period of time.

Growing community of inventors

Tokyo, Japan

Yasuto Higashida