20240026999. ELECTRIC RESISTANCE WELDED STEEL PIPE AND METHOD FOR MANUFACTURING THE SAME simplified abstract (JFE Steel Corporation)

ELECTRIC RESISTANCE WELDED STEEL PIPE AND METHOD FOR MANUFACTURING THE SAME

Organization Name

JFE Steel Corporation

Inventor(s)

Akihide Matsumoto of Chiyoda-ku, Tokyo (JP)

Ryo Nakazawa of Chiyoda-ku, Tokyo (JP)

Atsushi Matsumoto of Chiyoda-ku, Tokyo (JP)

Shinsuke Ide of Chiyoda-ku, Tokyo (JP)

ELECTRIC RESISTANCE WELDED STEEL PIPE AND METHOD FOR MANUFACTURING THE SAME - A simplified explanation of the abstract

This abstract first appeared for US patent application 20240026999 titled 'ELECTRIC RESISTANCE WELDED STEEL PIPE AND METHOD FOR MANUFACTURING THE SAME

Simplified Explanation

The present invention is about an electric resistance welded steel pipe and a method for manufacturing the same. The steel pipe consists of a base metal zone and a weld. The invention focuses on the steel microstructures in the middle of the base metal zone, where the volume fraction of a bcc phase is at least 80%, the average grain size is less than or equal to 15.0 μm, and the a value (defined by a predetermined equation) is between 0.55 and 0.85. The yield ratio in the pipe axis direction is less than or equal to 90%, and the Charpy absorbed energy at -40°C of the base metal zone is greater than or equal to 100 J.

• The invention is an electric resistance welded steel pipe with specific steel microstructures and mechanical properties.
• The steel microstructures in the middle of the base metal zone have a high volume fraction of a bcc phase.
• The average grain size of the steel microstructures is small.
• The a value, determined by a specific equation, falls within a specific range.
• The yield ratio in the pipe axis direction is limited.
• The Charpy absorbed energy at -40°C of the base metal zone is high.

Potential applications of this technology:

• Construction industry: The electric resistance welded steel pipe can be used in various construction projects, such as building structures, bridges, and pipelines.
• Oil and gas industry: The steel pipe can be utilized for transporting oil, gas, and other fluids in pipelines.
• Automotive industry: The pipe can be used in the manufacturing of automotive components, such as exhaust systems.

Problems solved by this technology:

• Improved strength and toughness: The specific steel microstructures and mechanical properties of the pipe provide enhanced strength and toughness, making it suitable for demanding applications.
• Enhanced weld quality: The electric resistance welding process used in manufacturing the pipe ensures a high-quality weld, reducing the risk of weld defects and failures.
• Cost-effective production: The method for manufacturing the pipe is efficient and cost-effective, allowing for mass production of high-quality steel pipes.

Benefits of this technology:

• High strength and toughness: The steel pipe exhibits high strength and toughness, making it suitable for withstanding heavy loads and harsh environments.
• Reliable weld integrity: The electric resistance welding process ensures a reliable and durable weld, minimizing the risk of leaks or structural failures.
• Cost savings: The efficient manufacturing method and high-quality properties of the pipe contribute to cost savings in various industries that rely on steel pipes.

Original Abstract Submitted

an electric resistance welded steel pipe and a method for manufacturing the same are provided. the present invention relates to an electric resistance welded steel pipe including a base metal zone and a weld. in the electric resistance welded steel pipe, steel microstructures at a wall-thickness-wise middle of the base metal zone are steel microstructures in which a bcc phase is present in a volume fraction greater than or equal to 80%, an average grain size is less than or equal to 15.0 �m, and an a value, defined by a predetermined equation, is 0.55 or greater and 0.85 or less; a yield ratio in a pipe axis direction is less than or equal to 90%; and a charpy absorbed energy at −40� c. of the base metal zone is greater than or equal to 100 j.