GB/T 16476-2018Scandium metal (English PDF)

Foreword

This Standard is drafted in accordance with stipulations in GB/T 1.1-2009. This Standard serves as a replacement of GB/T 16476-2010 Scandium Metal. In comparison with GB/T 16476-2010, there are the following main technical changes.

---Normative reference GB/T 17803 is added (please refer to Chapter 2);

3.1 Product Nameplate" is added (please refer to 3.1);

---Character nameplates Sc-5N5, Sc-5N, Sc-4N5 and Sc-4N are added (please refer to

---The method of expressing rare earth impurity content is modified; "(La + Ce + Pr + Nd + Sm + Eu + Gd + Tb + Dy + Ho + Er + Tm + Yb + Lu +Y)" is replaced by "rare earth impurity" (please refer to 3.2;

3.1 in Version 2010);

---The assessment index of aluminum (Al) in nameplate Sc-4N is adjusted from 0.0050% to 0.0070% (please refer to 3.2;

3.1 in Version 2010);

---The assessment index of copper (Cu) in nameplate Sc-4N is adjusted from 0.0025% to 0.0050% (please refer to 3.2;

3.1 in Version 2010);

---The assessment index of tantalum (Ta) in nameplate Sc-5N5, Sc-5N, Sc-4N5 and Sc-4N is adjusted respectively from 0.0020%, 0.0050% and 0.0080% to 0.0050% (please refer to 3.2;

3.1 in Version 2010);

---The assessment index of zirconium (Zr) in nameplate Sc-5N5, Sc-5N, Sc-4N5 and Sc-4N is adjusted respectively from 0.0010%, 0.0025% and 0.0040% to 0.0010% (please refer to 3.2;

3.1 in Version 2010);

1 Scope

China's national product standard for scandium metal. It specifies the requirements, the test methods, the inspection rules, and the packaging, marking, transport, storage and quality certificate for scandium metal, and it applies to scandium metal produced by metallothermic reduction or by the intermediate alloy route followed by vacuum distillation, for use in aviation, aerospace, electronic technology - electronics, nuclear, laser and electric light sources - and metallurgy. Scandium is the rare earth that behaves least like the others and costs the most. It is not concentrated in the usual rare earth ores; it is recovered in small quantities as a by-product of titanium, uranium, tungsten and aluminium processing, and world production is measured in tonnes. What it buys is remarkable: a fraction of a per cent of scandium in an aluminium alloy suppresses recrystallisation and refines the grain to give a weldable high-strength alloy that no other addition produces, and scandium in a sodium vapour lamp gives it the colour rendering that plain sodium lacks. Both applications are ruined by impurities, which is what the standard is about. The grades run from Sc-4N5 upward to Sc-5N5, and the requirement tables set the maximum content of each rare earth and non-rare-earth impurity for each grade. The 2018 edition tightened several of these against the 2010 edition it replaces, among them the limits on tantalum and zirconium in the higher grades - both of which come from the crucibles and the equipment used in distillation, not from the feed. The test methods, the sampling and acceptance rules, and the certificate that must accompany a lot complete the document. Issued on 13 July 2018 and in force since 1 April 2019.

This Standard specifies the requirements, test methods, inspection rules, packaging, marking, transportation, storage and quality certificate of scandium metal. This Standard is applicable to scandium metal that is manufactured with the method of metallothermic reduction or the method of intermediate alloy, and then, the method of vacuum distillation. The scandium metal shall be applied to aviation, aerospace (space navigation, rocket and missile), electronic technology (electronics, nuclear, laser, electric light source) and metallurgy, etc.

2 Normative References

The following documents are indispensable to the application of this Standard. In terms of references with a specified date, only versions with a specified date are applicable to this Standard. The latest version (including all the modifications) of references without a specified date is also applicable to this Standard.

GB/T 8170 Rules of Rounding off for Numerical Values & Expression and Judgement of Limiting Values

GB/T 13219-2018 Scandium Oxide

GB/T 17803 Designation System for Rare Earth Products

3 Requirements

3.1 Product Nameplate In terms of chemical composition, products shall be divided into 4 nameplates, namely, Sc-5N5, Sc-5N, Sc-4N5 and Sc-4N. The designation method for product nameplates shall comply with the stipulation in GB/T 17803.

3.2 Chemical Composition Product nameplate and chemical composition shall comply with the stipulation in Table 1. If the demand side has special requirements, the demand side and the supply side can have further negotiation.

6 Marking, Packaging, Transportation, Storage and

Quality Certificate