Kobe Steel, Ltd.

Nippon Kokan Kabushiki Kaisha

Tomokazu Godai

Shoji Minato

Isao Aida

Tsuneshi Ogawa

Tohru Sugiyama

Masatoshi Nakagaki

Katushi Nishimura

Makoto Yamada

Itaru Watanabe

Yutaka Nishikawa

Kazuo Takeuchi

Tetsuo Suga

Hiroshi Saita

Minoru Kobayashi

Koshiro Tsukada

Makoto Yamaga

Mutsuro Araki

Shingo Maki

Bunshiro Sakai

Yoshizo Hashimoto

Morihiko Sugino

Masaru Kondo

Yoshihisa Morioka

Kozo Nakai

Shinji Kimura

Yasuhito Takeuchi

Toboru Sugiyama

A composite wire containing a flux for use in gas-shielded arc welding of stainless steels which contains, in the flux, the following inorganic components with respect to the total weight of the wire: 0.1 to 10% by weight of an anhydrous silicate, and 0.01 to 0.75% of a metallic oxide having a melting point of no more than 888.degree. C.

Composite wire for stainless steel welding

A welding method for welding a base metal with a welding wire of specified alloy composition using a TIG welding process, automatically controlling an arc length between a nonconsumable electrode and the base metal, deflecting the arc forward in the welding advance direction by the influence of magnetic fields resulting from DC current flow through the welding wire to prevent arc blow, weaving the arc forward in the welding advance direction by pulsating the current flowing through the weld wire, and heat treating a final weld layer with the nonconsumable electrode.

Welding process

The invention is a process and apparatus for measurement of diffusible hydrogen within a metal, in which a metal sample is placed within an enclosed collector vessel for a predetermined time and at a predetermined temperature, and the total resultant effused gases within the collector vessel are fed to a gas chromatograph.

Process and apparatus for measurement of diffusible hydrogen

A surface flaw detector includes a light source capable of generating a laser beam, a material conveyance means provided for conveying a material to be examined in the direction transverse to the axis of the material and designed to let the material rotate on its axis at a fixed position or along the direction of conveyance, means for scanning the laser beam on the surface and in the axial direction of the material which is rotating on its own axis, optical means adapted to transmit the light reflected from the surface of the material to form a stationary optic image of the scanning means, light receiving means provided at the image forming position, and processing means adapted to discriminate the flaw signal upon receiving the output from the light receiving means.

Surface flaw detector

The present invention relates to a coated welding electrode containing at least 0.5% of Cr based on the total weight of the welding electrode and comprising a metal core and a coating flux composition. In this welding electrode, the content of Na and K components in the coating flux calculated as (Na.sub.2 O + K.sub.2 O) is reduced below 1% based on the total weight of the coating flux composition, whereby amounts of fumes generated at the welding step, especially the amount of toxic soluble Cr, are suppressed and minimized.

Coated welding electrode containing chromium

A bare welding electrode of a diameter of at least 3.0 mm for use in a large current gas shielded arc welding process in which steel for low temperature use is welded by a welding current of at least 500 A in a shielding gas composed mainly of an inert gas such as Ar, He or the like. In one aspect the electrode comprises up to 0.12% C, up to 0.8% Si, up to 3.0% Mn up to 0.25% Ti, at least one member selected from the group consisting of up to 4.0% Ni, up to 0.8% Cr and up to 1.0% Mo and the carbon equivalent (Ceq), of said electrode being up to 0.60% which is represented by the formula

Bare electrode for welding of low temperature steel

A method of manufacturing a thick, high-strength steel pipe for low temperature service comprising the steps of forming into tubular shape a steel plate having a thickness of over 12 mm and a specific composition, of which the C.sub.eq value is adjusted to less than 0.50, when the Mn content is less than 1.0 % whereas the C.sub.eq value is adjusted to less than 0.45 when the Mn content is over 1.0 % and less than 2.0 %, and nextly of welding said tube form at high speeds and high efficiency by the process of single electrode or multiple electrode large-current gas-shielded arc welding with one pass per electrode on each side of the seam at a specific condition, each electrode preferably consisting of a solid wire essentially containing less than 0.3 % Ti with or without the addition of less than 0.01 % B, and said steel pipe having, in its as-welded condition, mechanical properties such that the yield point of the base metal portion is over 60,000 psi and the weld zone has a maximum hardness of less than Hv10-280 and a Charpy test absorbed energy of over 7 Kg.m at -10.degree. F. Even when the C.sub.eq value of said steel plate is less than 0.65, a thick, high-strength steel pipe for low temperature service having equal mechanical properties to the above mentioned pipe may be manufactured, after welding, by subjecting the welded pipe to a post heat treatment in which the welded pipe is held at a temperature between 500.degree. and 700.degree. C for less than 1 hour.

Method of manufacturing thick, high-strength steel pipe for low

This invention provides a welding material for super low temperature steels which comprises not more than 0.2% carbon, 5 - 12% manganese, not more than 30% chromium, 4 - 8% niobium, 22% iron and not more than 1.5% silicon, the balance being substantially nickel, and which can give excellent strength and impact value to the weld zone. In one embodiment, the welding material is an integral body composed of a metal-forming material and a flux of lime or lime-titania in which the metal forming components are within the above range.

Welding material for super low temperature steels

Growing community of inventors

Kamakura, Japan

Tomokazu Godai