To the welder about aluminum alloys: alloy designations

 

First step in learning aluminum welding должно быть знакомство с самими алюминиевыми сплавами (литейными и деформируемыми): их обозначениями, properties and considerations regarding the combination of a welding aluminum alloy with a welded aluminum alloy.

Steel welding and aluminum welding

Choosing a suitable welding alloy for aluminum welding is different from choosing a welding alloy for welding steel. In the case of steels, the choice is mainly, to coordinate the strength properties of the welding and base metal. In the case of aluminum, many factors need to be considered., such as ease of welding, crack resistance, plastic, seam strength, corrosion resistance, operating temperature and the effect of heat treatment after welding. Some of these factors may be just as important., like tensile strength.

Therefore, for a good welding of aluminum, at least a brief acquaintance with many aluminum alloys is necessary, their characteristics and notation aluminum alloys. Understanding this system will help to use the right alloy in various conditions of use of the finished product..

Designations aluminum alloys

Sometimes the designations of aluminum alloys are incorrectly called "marking". Labeling is a different thing.. This is the physical application of an identifying inscription to a product or a semi-finished product – paint, prints the print, label sticker or tag attachment. Confusion comes from being, that in our standards, every alloy is not just an “alloy", but for some reason “alloy grade”.

In the global aluminum industry more than 600 aluminum alloys - more 400 deformable and more 200 foundry. All aluminum alloys are grouped by features of their properties., such as the ability to heat and strain harden and the main alloying elements.

Foreign designations of deformable alloys

Deformable alloys include those alloys., which are intended for cold or hot pressure treatment - rolling, pressing, shoeing, punching, drawing. In international practice, a designation system for deformable aluminum alloys has been adopted, four-digit. The first digit indicates the major alloying element, sometimes two elements. The second digit, if it is not zero, indicates base alloy modification, and the third and fourth are arbitrary numbers, by which alloys are distinguished. for instance, in the alloy 5183 numeral 5 points, that the main alloying elements in it is magnesium,, numeral 1 indicates the first modification of the base alloy 5083, figures 83 indicate a specific alloy in a series of alloys 5xxx.

An exception to the digital notation system is the 1xxx series, to which aluminum of various purity belongs, but not less than aluminum 99 %. In our standards, these various “aluminum” are called aluminum grades.. In this series, the last two digits indicate the minimum amount of aluminum allowed in the alloy above 99 %. for instance, alloy 1350 contains at least 99,50 % aluminum.

It should be noted, that in American standards, the letters AA are added to the four digits in front, for example, AA5053. The letters AA stand for the American Aluminum Association, an industry-specific aluminum organization., which, properly, developed and implemented this four-digit naming system. In ISO standard 209-1 add nothing to these numbers. In the European standard EN 573 add letters EN in front AW c hyphen, and full alloy designation 5183 выглядит так: EN AW-5183. The letters EN are, understandably, "European norm", A – aluminium и W – wrought (деформируемый). However, usually, в технической литературе обычно применяют «голые» цифры (плюс иногда буквы сзади) без всяких букв спереди.

Designations of aluminum alloys in accordance with GOST 4784-97

В отечественных стандартах (ГОСТ) – своя, still “Soviet”, alphanumeric system for deformable alloys, although the main groups-series of alloys coincide with international. In GOST 4784 alloy designations additionally indicate, there, where possible, and four-digit international designations. More information on the designations according to GOST 4784 look. here.

Foreign designations of cast alloys

Foundry alloys are designed for castings from them of finished parts and products. The international casting designation system is based on three digits to the left of the decimal point and one digit to the right of it. The first number indicates the main alloying elements of the alloy. The second and third digits give when registering the alloy for its unambiguous identification of the alloy within this series.

Numeral, which follows the decimal point, points, что сплав определен для отливок (.0) или для слитков (.1 или .2). A capital letter before the first digit indicates a modification of the base alloy. for instance, in the popular casting alloy A356.0, the letter A indicates a modification of the base alloy 356.0. Numeral 3 indicates the main alloying elements of this alloy are silicon + copper and / or magnesium. The numbers "56" identify a particular alloy within the 3xxx.x series, and "0" indicates, what is an alloy for casting, not for ingot.

Designation of cast alloys in accordance with GOST 1583-93

The domestic classification of cast aluminum alloys and their alphanumeric designation system is determined by GOST 1583-93. For details, see. here.