More on alloys AD31, 6060 and 6063

The vast majority of aluminum profiles in the world made from alloys 6060 and 6063. Both are represented in the European Standard EN 573-3. Their domestic analogue - alloy AD31 GOST 4784-97 (table). Note, that amendments to the 2000 year to GOST 4784-97 alloy AD31 completely coincided with the alloy 6063.

Abortion AD31 before and after 2000 of the year

As a result of amendments 2000 AD31, the chemical composition of the alloy is very much changed in the direction of increasing the content of impurities, that is, he became a "dirty". That was done, must be understood, to expand the use of aluminum scrap, which always has a high content of impurities. These corrections were as follows: the maximum iron content was changed from 0,35 on 0,5 %, copper - with 0,10 on 0,1 %, zinc - with 0,10 on 0,2 %, Manganese - a 0,10 on 0,1 % and titanium - 0,10 on 0,15 %.

Terms of the chemical composition of rounding

«Bezobidnoe», at first sight, change the maximum content of copper and manganese 0,10 to 0,1 % also aims to increase the permissible impurity content. This is due to the rounding rules, which are used when processing data of chemical analysis of the alloy. for instance, supposing, spectrometer shows that copper content of the aluminum alloy sample in the form of 0,1499 – with four significant digits. If the maximum copper content is standard 0,1 %, the, rounding to one decimal place, get 0,1499 ≈ 0,1 %, and, thus, test alloy "fit" in the requirements of the standard. If the requirement of the standard is 0,10 %, it is necessary to have rounded to two significant figures, and we get 0,1499 ≈ 0,15 % – alloy has obviously does not fit the requirements of the standard.

The figure below via “transparent” rectangles shown as the number of significant digits in the chemical composition of the alloy AD31 affects margins impurities.


Figure – Impurity tolerances in aluminum alloys:
AD31 GOST 4784-97 (2000);
6060 and 6063 by EN 573-3;
606035 – the company's internal alloy Hydro

Alloy AD31 GOST 4784-97

This aluminum alloy AD31 GOST 4784-97 amended 2000 It has been applied in the manufacture of extruded sections according to GOST 8617-81 and the Ukrainian standard DSTU B V.2.6-30: 2006 (GOST 22233-93), because they both continue to refer to GOST 4784. GOST 8617 produce general-purpose profiles, a according to DSTU B V.2.6-30: 2006 (GOST 22233-93) - profiles for building envelopes.