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This standard was developed in accordance with the rules of GB/T 1.1-2009.
This standard replaces "Designation and Composition of Titanium and Titanium Alloys" (GB/T 3620.1-2007).
The following main technical changes have been made with respect to GB/T 3620.1 - 2007:
——the designation and composition of industrial unalloyed titanium in GB/T 3620.1 - 1994 are recovered;
——the designations of industrial unalloyed titanium are changed uniformly, and added with letter "G";
——the designations are listed according to the classification of titanium;
——the editorial errors of designations TA22-1, A24, TC15 and TC17 are revised;
——the content of Si in TA19 is revised;
——eight newly registered α and near α alloy designations are added, including TA29, TA30, TA31, TA32, TA33, TA34, TA35 and TA36;
——six newly registered β and near β alloy designations are added, including TB12, TB13, TB14, TB15, TB16 and TB17;
——six newly registered α-β alloy designations are added, including TC27, TC28, TC29, TC30, TC31 and TC32;
——the naming rules for titanium alloy designations are added;
——the Implementation requirements on the designation and composition of industrial unalloyed titanium are specified.
This standard is under the jurisdiction of National Technical Committee on Nonferrous Metals of Standardization Administration of China (SAC/TC 243).
The previous editions of the standard replaced by this standard are as follows:
- GB/T 3620-1983, GB/T 3620.1-1994 and GB/T 3620.1-2007.
Designation and Composition of Titanium and Titanium Alloys
1 Scope
This standard specifies the designation and composition, etc. of titanium and titanium alloy products.
This standard is applicable to various finished products and semifinished products (including ingot) made of titanium and titanium alloy through press working.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 3620.2 Titanium and Titanium Alloys - Permissible Variations of Chemical Composition for Wrought Product Analysis
GB/T 4698
(All Parts) Sponge Titanium, Titanium and Titanium Alloys
GB/T 8170 Rules of Rounding Off for Numerical Values & Expression and Judgment of Limiting Values
3 Compositions
3.1 Designations and compositions
3.1.1 The designations and compositions of titanium and titanium alloy products shall meet the requirements specified in Tables 1, 2 and 3, among which Table 1 is for the those of industrial unalloyed titanium, α and near α titanium and titanium alloys; Table 2 is for those of β and near β; Table 3 is for those of α-β titanium alloy.
3.1.2 Boron shall be added according to its nominal amount, and the measured data shall be reported for reference.
3.1.3 When only upper limit is specified for Si in Tables 1, 2 and 3, Si shall be controlled as an impurity element.
3.2 Other elements
3.2.1 Other elements refer to the inherent microelements during production process of titanium and titanium alloys, rather than elements added artificially.
3.2.2 Generally, other elements include Al, V, Sn, Mo, Cr, Mn, Zr, Ni, Cu, Si and Y (alloy elements in the designation shall be removed). The content of Y shall not be larger than 0.005%. Other special requirements requested by users, if any, shall be determined through negotiation between both parties and then noted in the contract.
3.2.3 The supplier may not inspect other elements when the products leave factory, and may conduct sampling inspection if required and noted by the user in the contract.
3.3 Composition tolerance
When the demander takes samples from the products for check analysis on the composition, the composition tolerance shall meet the requirements of GB/T 3620.2.
4 Composition Analysis and Analysis Report
4.1 The arbitrary analysis on composition of titanium and titanium alloy products shall be conducted according to GB/T 4698, while routine inspection may be conducted according to ICP or other approved methods.
4.2 Unless otherwise stated in the product standard, the supplier may take samples from titanium and titanium alloy ingot (from finished product in case of hydrogen element) for composition analysis of the product.
4.3 The composition of titanium and titanium alloy products is allowed to be subjected to second analysis, the result of which will be regarded as the final judgment basis.
4.4 The significant digits of the analysis values in the composition analysis report shall be consistent with those of corresponding limit values of corresponding designations in this standard. The numbers after significant digits shall be rounded off according to the rules of GB/T 8170.
5 Others
5.1 See Annex A for the designation and composition of titanium and titanium alloys deleted in the revision of GB/T 3620.1.
5.2 See Annex B for the corresponding relationship between industrial unalloyed titanium and unalloyed titanium designations in ASTM standard system in Table 2 .
5.3 See Annex C for the naming rules for designations of titanium and titanium alloy.
5.4 See Annex D for all designation and composition of industrial unalloyed titanium in this standard as well as the implementation description of relevant product standards.
Foreword i
1 Scope
2 Normative References
3 Compositions
4 Composition Analysis and Analysis Report
5 Others
Annex A (Informative) Designations and Compositions of Titanium Alloys Deleted
Annex B (Informative) Corresponding Relationship between Industrially Unalloyed Titanium in Table 2 of this Standard and the Designations of Unalloyed Titanium in ASTM Standard System
Annex C (Normative) Naming Rules for Titanium and Titanium Alloy Designations
Annex D (Informative) Statement on Implementation of this Standard and Relevant Standards