GB/T 9808-2023 in English

Background of Standard Update and Technological Evolution

GB/T 9808-2023 is the latest national standard in the field of seamless steel pipe for drilling, replacing the original GB/T 9808-2008 version. This revision mainly optimizes and improves the technical requirements, chemical composition, mechanical properties and manufacturing methods of steel pipes to meet the development needs of modern drilling technology.

Compared with the old version, the new standard adds term definitions, and adjusts key indicators such as wall thickness allowable deviation, length deviation, and curvature of steel pipes. At the same time, new grades (such as ZT750, ZT850, and ZT950) are introduced and some outdated grades (such as ZT540 and ZT740) are eliminated. These changes fully reflect the evolution of seamless steel pipe technology for drilling and changes in industry needs.

Comparative analysis of standard framework

Grades and application scenarios

The new standard introduces several new grades, which are suitable for different drilling scenarios:

• ZT750: Suitable for drill pipe materials with medium strength requirements.
• ZT850: Used for high-strength and impact-resistant geological core drilling pipe materials.
• ZT950: Suitable for engineering drilling casing materials under extreme working conditions.

Implementation suggestions and precautions

To ensure the effective implementation of the standard, it is recommended that manufacturers:

1. Strictly control the smelting process of chemical composition to avoid excessive impurity elements.
2. Strengthen non-destructive testing capabilities, especially the investment in eddy current testing and ultrasonic testing equipment.
3. Develop special production processes and quality control plans for new grades (such as ZT750, ZT850, and ZT950).