Nisshin Steel Co., Ltd.

Nippon Tungsten Co., Ltd.

Shigeo Matsubara

Takefumi Nakako

Toshiharu Kittaka

Jun Kurobe

Hiroshi Asada

Yusuke Hirose

Toshiro Yamada

Ryuji Tanoue

Kenji Okamura

Shuichi Teramoto

Takeyuki Yoshida

Shingo Mukae

Shouji Inoue

Hiroki Kanazawa

Yukimi Miwa

Iwao Katayama

Provided is an electrode () which has a double structure including Cu or a Cu alloy as an electrode body () and a core material () made of W, Mo, a W-based alloy, or a Mo-based alloy embedded in a surface of the electrode body () which is abutted against a material to be welded, the core material () being formed by using W, Mo, the W-based alloy, or the Mo-based alloy which is in the form of a fibrous structure extended by sintering, swaging, and annealing in an electrode axis direction, the fibrous structure having a horizontal cross-sectional average particle diameter of 50 &#x3bc;m or more and an aspect ratio of 1.5 or more. The electrode () can be used as an inexpensive electrode obtained by suppressing particle dropping/attrition and defects in electrodes for spot welding, in which heat and pressure are applied repeatedly, stably enhancing durability.

Electrode for spot welding

A high-strength steel pipe rockbolt has an expansive rockbolt main body prepared by processing a high-strength steel sheet of 1.8-2.3 mm in thickness with a tensile strength of 490-640 N/mmand an elongation of 20% or more into a welded pipe and roll-forming the welded pipe into a shaped pipe having one or more concavities extending along an axial direction. Use of the high-strength steel sheet ensures sufficient strength of the shaped pipe regardless of a decrease in thickness. The thin welded pipe is also advantageous in resistance to cracking caused by accumulation of strains introduced during roll-forming, swaging both ends of the welded pipe and hydraulic expansion. Moreover, expansive deformation of the shaped pipe is initiated by injection of a pressurized fluid at a low pressure, so that the expansive deformation is completed in a short time period with an improved working efficiency.

Rockbolt of high strength steel pipe and method of manufacturing the same

A zirconia oxygen sensor for measuring oxygen potential in the molten bath of a metal or alloy having a melting point of 350-550.degree. C., which comprises a reference electrode which is of a substance having a melting point of the same level as or lower than the metal or alloy of which the oxygen potential is to be measured and being liquid at the measurement temperature and is open to the atmosphere, a vessel of a zirconia solid electrolyte containing 5-10% yttria or 10-20% of calcium oxide (CaO) and a lead wire which connects the reference electrode and said molten metal or alloy and its use are disclosed.

Zirconia oxygen sensor

Growing community of inventors

Tokyo, Japan

Shigeo Matsubara