High-strength structural steel
In this category, are summarized the steel materials, which are predestined for general use, with a slightly higher yield point compared to general structural steels and good weldability. The good machining properties and their high suitability, keep the level of their use still very high despite the large number of steel grades.
In addition to the properties, such as the strength parameters, machinability and behaviour in the event of temperature fluctuations and after the installation process (welding), the designer must also consider the economic view of costs. The St52-3 (1.0570-S355J2G3) with its “newly” assigned bulky name is used again and again. Through improved properties with cleaner steel production processes and the volume check (UT test) of the material, it is possible to safely design in a mass-saving manner in order to reduce the construction costs of the designed projects. The permissible stresses for the endurance and fatigue strength verification can easily be taken from the standards in a statistically secure manner. Values with calculation temperatures up to 300° C are also given.
A further increase in usability is achieved with the so-called fine-grain structural steels (1.8928-S690QL), which can then also meet the increased safety requirements for hoists and crane systems. In order to achieve the fine grain and aging resistance, this material contains a slightly higher Al content (> 0.015%).