Welded components for machines. Characteristics of the grades

This text and the following tables should be read in conjunction with the article [BM 5 187] .

The aim of this article is to provide the designer with a range of grades that can be used in a structure with a mechanical function made up of elements assembled by welding.

This article presents two tables summarizing the various standardized grades for the two main categories of materials: steels and aluminum alloys. These tables provide the reader with a range of technical comparisons concerning the production method, mechanical properties and weldability of these different grades for a given application.

The presentation of steel and aluminum alloy grades, together with the normative reference, indicates :

• the type of product involved (flat products, sections, bars, welded or non-welded tubes, forged, cast);

• the reference metallurgical state (heat or mechanical treatment);

• the product's usual destination ;

• guaranteed minimum yield strength at room temperature ;

• the suitability of the grade for welding, taking into account, among other things, the maximum thickness specified in the application field concerned by the normative document.

It goes without saying that such a classification, based on normative documents which, by definition, are constantly evolving over time, needs to be updated periodically. However, the author has deliberately retained certain grades of steel and aluminum alloys defined by national standards that have been superseded by the new European EN standards, which have not retained these grades even though producers still supply them.