GB/T 27677-2017Aluminium hardeners (English PDF)

3.1 Aluminium hardeners

An alloy made of aluminium as a matrix and melted with other metals or non-metals at elevated temperatures. It is used to adjust and control the chemical composition and structure of cast aluminium alloys or wrought aluminium alloys.

4.1 Product classification

4.1.1 Representation method of aluminium hardener designation

The designation of aluminium hardeners is composed of "Al" + the symbol of the main alloying element + the nominal mass fraction of the main alloying element. The main alloying elements are arranged in descending order by their element mass fractions.

4.1.2 Groups and designations of aluminium hardeners

Aluminium hardeners are divided into 39 groups according to the first main alloying element, as shown in Table 1.

4.1.3 Product category, dimensions and piece weight

The category, dimensions and piece weight of aluminium hardeners shall comply with the requirements in Table 2. If the buyer requires other dimensions or weights, it shall be determined through negotiation between the supplier and the buyer, and noted in the order form (or contract).

4.1.4 Marking and examples

The marking of aluminium hardeners is expressed in the order of product category, number of this Standard, designation of the aluminium hardener, designation of the raw aluminium ingot (which can be omitted when designation Al99.70 is selected), dimensions and piece weight. Examples of marking are as follows. […]

4.2 Chemical composition

The chemical composition of the designation of aluminium hardeners shall comply with the requirements in Table 3.

4.5 Appearance

The appearance of aluminium hardeners is not allowed to contain slag inclusions, corrosion, inclusions, oil stains or any foreign matter. It is allowed to have oxide films, wrinkles or shrinkage cracks that do not affect its use.

5.1 Chemical composition

5.1.1 The chemical composition analysis method shall comply with the provisions of GB/T 20975 (all parts) or GB/T 7999. The arbitration analysis shall adopt the method specified in GB/T 20975 (all parts).

5.1.2 The determination of analysis value is based on the rounding comparison method; the value rounding rules shall be carried out in accordance with the relevant provisions of GB/T 8170; the rounding digit shall be consistent with the limit digits specified in Table 3.

5.2 Fracture structure

Fracture structure shall be inspected in accordance with the provisions of GB/T 3246.2.

5.3 Microstructure

Microstructure shall be inspected in accordance with the provisions of GB/T 3246.1.

5.4 Appearance

Visually inspect the appearance under natural scattered light.

6.1 Inspection and acceptance

6.1.1 The aluminium hardeners shall be inspected by the supplier to ensure that the quality of the aluminium hardeners complies with the provisions of this Standard and the order form (or contract), and a quality certificate shall be filled in.

6.2 Batch

Aluminium hardeners shall be submitted for inspection in batches, and each batch shall be composed of aluminium hardeners of the same melting order.

6.3 Inspection items

Each batch shall be inspected for chemical composition, fracture structure and appearance. Aluminium hardeners of designations AlTi6A, AlTi6, AlTi10A, AlTi10, AlTi5B1A, AlTi5B1, AlZr5A, AlZr5, AlZr10A, AlZr10, AlZr15A, and AlZr15 shall also be inspected for microstructure. When users have requirements for the microstructure of aluminium hardeners of other designations, the required aluminium hardeners shall be inspected for microstructure on a batch basis.

6.4 Sampling

The sampling of aluminium hardeners shall comply with the requirements in Table 7.

6.5 Determination of the test result

6.5.1 When the chemical composition of any sample is unqualified, if the melting order of the product can be distinguished, judge the melting order that is represented by the sample as unqualified; inspect other melting orders in turn, and deliver the qualified ones. If the melting order cannot be distinguished, judge the batch as unqualified.

7.1 Marking

7.1.1 Product marking

The aluminium hardener that has passed the inspection shall be accompanied by the following imprint (or label).

7.1.2 Packaging markings

The packaging box markings of aluminium hardeners shall comply with the regulations of GB/T 3199.

7.2 Packaging, transportation, storage

7.3 Quality certificate

Each batch shall be accompanied by a quality certificate that meets the requirements of this Standard, stating.