Structural steel grades
The available structural steel grades according to European, American, Russian and Japanese standards are shown in tables 2, 3 (EN), 10 (ASTM), 11 (GOST) and 12 (JIS). These summary tables show the main requirements of the standards regarding the mechanical characteristics and the chemical composition of the steel grades.
Other grades (Canadian CSA standards for instance) are available upon request.
Table 13 shows a list of corresponding designations between the European standards as well as the HISTAR® grades with those from the American, Canadian, Japanese and the former national European standards.
The steels are typically delivered with a Si content ranging between 0.14% and 0.25%, and are as such capable of forming a zinc layer during hot-dip galvanisation (diagram 1).
As the phosphorus content of these steels is usually lower than 0.035%, it does not have any influence on the final thickness of the coating in the considered Si range.
Thickness of the zinc coating depending on different parameters
The mechanical characteristics of ArcelorMittal’s sections are improved by precise control of the temperature during the rolling process. These steels, produced using thermomechanical rolling (delivery condition M), feature improved toughness values thanks to a lower carbon equivalent and a fine microstructure when compared with normalised steels.
With regard to their technological properties,the thermomecanically rolled steels have good cold forming properties. Similar to conventional structural steels, they can be flame straightened, provided specific maximum temperatures are not exceeded.
In case stress relieving is considered for reducing residual stresses, the usual parameters concerning temperature range and heating time according to the rules of practice must be applied. Hot forming, which is anyway uncommon for the fabrication of sections, must not be performed in accordance with EN 10025:2004.