Review of microalloyed structural plate metallurgy: alloying, rolling, heat treatment

The historical development of structural steels and their main requirements are presented. The reduction of the carbon content and the use of microalloying and alloying elements for grain refinement as well as for precipitation and solid solution hardening led to HSLA steel grades with good toughness and weldability. Modern technologies in steelmaking, hot rolling and heat treatment in combination with the chemical composition are used for an economical production of plates with special requirements. The rules and recommendations for fabrication are mentioned. Cumulative frequencies of mechanical properties and some examples of completed structures show the successful application of microalloyed steels. (AU)