There are differences between the Chinese and international standards for the titanium industry in terms of chemical composition, mechanical properties, naming rules, process requirements and application areas. The following is a specific comparative analysis:
1. Differences in chemical composition
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%), 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%), stricter impurity control (such as O≤0.18%, Fe≤0.20%).
Ultra-low interstitial element (ELI) alloys
Chinese standards (such as TA1ELI, TC4ELI) clearly stipulate that O≤0.13% and Fe≤0.20%, which is consistent with international standards (such as ASTM F67), but the brand naming rules 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 the national standard (GB/T) does not cover this field and needs to rely on corporate standards (such as Baoti Q/BT 472).
International standards (such as SEMI F67) have formed mature specifications and are used in high-end fields such as semiconductor targets.
2. Differences in mechanical properties
Strength index
The tensile strength requirements of titanium alloy bars in Chinese standards (such as GB/T 2965-2023) are basically consistent with those in international standards (such as ASTM B381), but there are differences in the details of the heat treatment process of some alloys (such as TC4).
The mechanical property requirements of medical titanium alloys (such as TC4 ELI) are highly compatible with ISO 5832-3, but they need to pass additional biocompatibility tests (such as ISO 10993).
Plasticity index
The elongation requirements of Chinese standards are slightly lower than those of international standards (such as ASTM B265 requires ≥20%, while GB/T 3621-2022 is ≥18%), which may affect the application of complex forming processes.
3. Naming rules and brand system
Chinese standards
Use the "TA/TB/TC" series naming (such as TA1 for industrial pure titanium, TC4 for Ti-6Al-4V), and some brands (such as TA8-1, TA25) are unique to China.
GB/T 3620.1-2023 updated in 2023 adds a variety of alloys (such as low palladium alloy TA9-1), but the brand naming rules have not yet been fully aligned with international standards.
International standards (ISO/ASTM)
ISO 23515-2022 was formulated by China and unified the international titanium brand naming rules for the first time, but ASTM brands (such as Gr.5 for 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), and Chinese standards are more detailed in the field of special alloys (such as titanium ruthenium alloy TA26).
4. Process performance and testing methods
Dimension tolerance
The dimensional tolerance requirements of Chinese standards (such as GB/T 39799-2021) for rods and wires 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 of Chinese standards for surface defects (such as scratches and oxidation) are similar to those of international standards (such as ISO 13680), but the surface particle size of high-purity titanium for semiconductors (such as SEMI M52 requires ≤10 particles/cm²) needs to be supplemented by enterprise standards.
Testing methods
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) is different from that of international standards (such as ASTM E1409).
5. Environmental protection and special field requirements
Environmental protection standards
China's GB 25468-2010 has stricter emission limits for titanium industrial wastewater and waste gas than some international standards (such as the US EPA standard), but has not yet fully aligned with the EU REACH regulations.
Nuclear industry and medical
Chinese medical titanium materials (such as GB/T 13810-2007) must meet biocompatibility tests (equivalent to ISO 10993), but the control of activated elements for nuclear industry titanium (such as Co≤1ppm) still relies on the supplementary requirements of ASTM B338.
6.summary suggestions
Purchasing and production
: It is recommended to give priority to international standards (ASTM/ISO) for high-end applications (such as semiconductors and medical), and Chinese standards (GB/YS) can be selected for general industries.
International cooperation
: Pay attention to the progress of international standards such as ISO 23515 led by China, and promote the internationalization of Chinese brands.
Technology upgrade: Strengthen the formulation of standards for 4N grade high purity titanium and special alloys (such as Ti-2Al-2.5Zr) to narrow the gap with the international level.
Welcome to consult us to learn more about titanium materials.
Nicole
Company: Baoji Jimiyun Dynamic Co., Ltd
Country:China
Add:Baoti road,Jintai,Baoji city,Shaanxi,China
Cel:+86 13369210920
Gmail:nicole@jmyunti.com
Website:www.jm-titanium.com
