Nippon Steel Sumitomo Metal Corporation

Sumitomo Metal Industries, Inc.

Junichi Nishimori

Tomio Yamakawa

Keishi Matsumoto

Kazuhiro Shimoda

Yuji Inoue

Yasuyoshi Hidaka

Takahisa Kato

Shuichi Akiyama

Koji Muramatsu

Hiroaki Murakami

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

When a hollow billet is inserted into a container, and hot expanding piercing is downwardly performed by using a plug, hot piercing is performed by using a formed glass complex comprising a ring-shaped formed glass part and a ring-shaped projecting part. The ring-shaped formed glass part assumes a disc shape having a circular opening for allowing a plug to be inserted at the center thereof. The ring-shaped projecting part is attached to the opening of the ring-shaped formed glass part, and assumes a ring shape projecting perpendicularly to the ring-shaped formed glass part. Thereby, the piercing work can be done safely, and defects can be prevented from occurring on the inner surface of the billet.

Upper-end formed glass complex for hot expanding piercing and method of manufacturing billet for hot extrusion pipe making

Growing community of inventors

Kobe, Japan

Junichi Nishimori