Designation system for steels
The European standard EN 10027: 1992 defines, in combination with the CEN report CR10260, the designation system for steel. The usual symbols for structural steels are shown in Table 1.
Structural Steels
The available structural steel grades according to European, American, Russian and Japanese standards are shown in Table 2, Table 3 (EN), Table 10 (ASTM), Table 11 (JIS) and Table 12. 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 0,15% 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 0,040%, it does not have any influence on the final thickness of the coating in the considered Si range.
The mechanical characteristics of ArcelorMittal's sections can be improved by precise control of the temperature during the rolling process. 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 however uncommon for the fabrication of sections, must not be performed.
HISTAR® AND FRITENAR®
The high yield strength, good toughness at low temperatures and excellent weldability of HISTAR® and FRITENAR® steels make them a cost-effective choice in the design of multi-storey buildings and large span trusses.
HISTAR® steels are available in yield strengths of 355 MPa and 460 MPa, FRITENAR® steels are available in 355 MPa.
The yield strengths of HISTAR® steels used in the construction industry have improved characteristics over the whole product thickness range. Compared with basic steels, these exceptional mechanical properties can reduce construction weight by 25-50 % depending on structural lay-out and naturally provide high strength and exceptional durability.
The HISTAR® and FRITENAR® Offshore grades in Table 8 are in compliance with EN 10225: 2001.
Detailed data on the HISTAR® Offshore and FRITENAR® Offshore steels are available upon request.