Showa Denko Kabushiki Kaisha

Ryoichi Yoshimura

Norio Hirokawa

Takashi Shoji

Toshio Morimura

Tadao Hirano

Munetaka Honda

Tsuneo Kawachi

Hiroshi Saito

The present invention relates to a refining agent used for deoxidation, desulfurization, and dephosphorization of molten steel by a ladle refining, as well as methods for producing such a refining agent. The general practice in ladle refining is to use for the refining agent both so-called flux, which is mainly composed of CaO, and a Ca-based metallic additive. In conventional practice, the flux and the Ca-based metallic additive are added to the molten steel separately. It is an object of the present invention to provide a refining agent, wherein the flux and metallic CaO component act highly effectively on the molten metal. A refining agent for metal according to the present invention essentially consists of: a Ca alloy, which essentially consists of Ca and at least one element selected from the group consisting of Al and Si, and a flux mainly composed of CaO and Al.sub.2 O.sub.3, the Ca-alloy phases and the flux phases being integrally bonded to one another. According to the method of present invention, the reduction of CaO by the metallic reducing agent allows the Ca alloy phase and flux phase to be very uniformly mixed with one another, with the result that the vaporization loss of metallic Ca can be suppressed to a high extent.

Refining agent of molten metal and methods for producing the same

One of the difficulties in developing a metallic material which is corrosion resistant to caustic alkaline solutions is that the corrosiveness of these solutions is different depending upon the process for producing the same. The chromium alloyed steel developed according to the present invention, contains, from 29 to 31%, of Cr; not more than 3% of Mo; not more than 0.005% of C; at least one element selected from the group of Nb and Ta in an amount, which follows the equation

Chromium-alloyed steel which is corrosion resistant to caustic alkaline

A slaking property of a lime bearing agent for use in the refining, particularly in the injection refining, of a ferrous melt is essentially eliminated by providing the agent with a special form, i.e. an uncrushed, granular form solidified from molten drops. Hydrogen pick up of the ferrous melt from the refining agent is avoided and an excellent refining effect of the ferrous melt is achieved by the refining agent of the present invention.

Lime bearing agent for use in refining of ferrous melt

Reduced pellets are manufactured by mixing a powdered raw metallurgical ore such as of iron, chromium or manganese with a carbonaceous reducing material obtained by heat-treating anthracite, at temperatures between 600.degree. C and 1000.degree. C and subsequently pulverizing the heat-treated anthracite, pelletizing the resultant mixture and thereafter roasting the pellets.

Growing community of inventors

Yokohama, Japan

Ryoichi Yoshimura