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What are the differences between Chinese and international standards for the implementation of standards in the titanium industry?

There are differences between Chinese standards and international standards for the titanium industry in terms of chemical composition, mechanical properties, naming conventions, process requirements, and application areas. The following is a specific comparative analysis:
1、 Chemical composition differences
Industrial pure titanium (such as TA1/TA2 vs ASTM Grade 1/Grade 2)
Chinese standard (GB/T 3621-2022)
TA1 (purity ≥ 99.8%), TA2 (purity ≥ 99.6%), with slightly wider impurity requirements (such as O ≤ 0.20%, Fe ≤ 0.30%).
International standard (ASTM B265)
Grade 1 (purity ≥ 99.9%), Grade 2 (purity ≥ 99.5%), with stricter impurity control (such as O ≤ 0.18%, Fe ≤ 0.20%).
Ultra low gap element (ELI) alloy
Chinese standards (such as TA1ELI and TC4ELI) clearly stipulate that O ≤ 0.13% and Fe ≤ 0.20%, which is consistent with international standards (such as ASTM F67), but the naming rules for grades are different.
High purity titanium (4N grade and above)
Chinese standards (such as YS/T 1299-2019) have clear requirements for Fe ≤ 10ppm and O ≤ 50ppm for 4N grade titanium, but national standards (GB/T) do not cover this field and rely on enterprise standards (such as Baotai Q/BT 472).
International standards such as SEMI F67 have formed mature specifications and are used in high-end fields such as semiconductor target materials.
2、 Differences in mechanical properties
Intensity index
The tensile strength requirements for titanium alloy bars in Chinese standards (such as GB/T 2965-2023) are basically consistent with international standards (such as ASTM B381), but there are differences in the details of heat treatment processes for some alloys (such as TC4).
The mechanical properties of medical titanium alloys (such as TC4 ELI) are highly compatible with ISO 5832-3, but require additional biocompatibility testing (such as ISO 10993).
Plasticity index
The requirement for elongation rate in Chinese standards is slightly lower than that in international standards (such as ASTM B265 requiring ≥ 20%, while GB/T 3621-2022 requires ≥ 18%), which may affect the application of complex forming processes.
3、 Naming rules and brand system
Chinese standards
Using the "TA/TB/TC" series naming (such as TA1 for industrial pure titanium and TC4 for Ti-6Al-4V), some grades (such as TA8-1, TA25) are unique to China.
The updated GB/T 3620.1-2023 includes various alloys (such as low palladium alloy TA9-1), but the naming rules for grades have not yet fully aligned with international standards.
International Standard (ISO/ASTM)
ISO 23515-2022 was developed under the leadership of China, which for the first time unified the international naming convention for titanium grades. However, ASTM grades (such as Gr.5 corresponding to Ti-6Al-4V) are still the mainstream in the industry.
International standards cover a wider range of alloy types (such as Ti-3Al-2.5V pipes), while Chinese standards provide more detailed specifications in the field of special alloys (such as titanium ruthenium alloy TA26).
4、 Process performance and testing methods
Dimensional tolerance
The dimensional tolerance requirements for bar and wire materials in Chinese standards (such as GB/T 39799-2021) are basically consistent with ASTM B381, but the standards for some special-shaped materials (such as square tubes) (such as GB/T 41750-2022) are unique to China.
Surface quality and cleanliness
The control requirements for surface defects (such as scratches and oxidation) in Chinese standards are similar to those in international standards (such as ISO 13680), but the surface particle size of high-purity titanium used in semiconductors (such as SEMI M52 requirement ≤ 10 particles/cm ²) needs to be supplemented by enterprise standards.
Testing method
The chemical composition analysis adopts GB/T 4698 (equivalent to ISO 6967), but the detection accuracy of gas elements (O/N/H) (such as GB/T 4698.7-2019) differs from international standards (such as ASTM E1409).
5、 Environmental Protection and Special Field Requirements
Environmental standards
China's GB 25468-2010 has stricter emission limits for titanium industry wastewater and exhaust gas than some international standards (such as the US EPA standard), but it has not yet fully aligned with the EU REACH regulation.
Nuclear Industry and Medical
Chinese medical titanium materials (such as GB/T 13810-2007) need to meet biocompatibility testing (equivalent to ISO 10993), but the control of activated elements (such as Co ≤ 1ppm) for titanium used in the nuclear industry still relies on ASTM B338 supplementary requirements.
6、 Summary and Suggestions
Procurement and Production
For high-end applications such as semiconductors and healthcare, it is recommended to prioritize the use of international standards (ASTM/ISO), while general industries can choose Chinese standards (GB/YS).
International cooperation
Pay attention to the progress of international standards such as ISO 23515 led by China and promote the internationalization of Chinese brands.
Technological upgrade
Strengthen the standardization of 4N grade high-purity titanium and special alloys (such as Ti-2Al-2.5Zr) to narrow the gap with international standards.

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