Many wire products (e.g. nets) are made from galvanized material. The hot dip galvanizing process gives the possibility of applying in a respectively thick coat of zinc (also depending on the time of staying wires in the bath) which provides the protection of the product against corrosion. In the available literature there were no research concerned with the influence of hot dip galvanizing process on the mechanical properties TRIP structure steel wires. Therefore, an experiment was carried out in laboratory conditions allowing the determination of the influence of hot dip galvanizing process parameters on the mechanical properties (tensile strength UST and yield strength YS) of TRIP steel wires as well as on the amount of retained austenite in their structure. It has been stated that the hot galvanizing process of TRIP steel wires influences, proportionally to the time of staying wires in zinc bath, on their plastic properties (the increase in yield strength YS) as well as the decrease in the amount of retained austenite in their structure. Such a phenomenon can be caused by stresses responsible for rapid heating of the wire put in the zinc bath in temperature of 450°C and by the strengthening of the materials resulting from the transformation of retained austenite.

The paper addresses the macro- and microsegregation of alloying elements in the new-developed Mn-Al TRIP steels, which belong to the third generation of advanced high-strength steels (AHSS) used in the automotive industry. The segregation behaviour both in the as-cast state and after hot forging was assessed in the macro scale by OES and by EDS measurements in different structural constituents. The structural investigations were carried out using light and scanning electron microscopy. A special attention was paid to the effect of Nb microaddition on the structure and the segregation of alloying elements. The tendency of Mn and Al to macrosegregation was found. It is difficult to remove in Nb-free steels. Microsegregation of Mn and Al between austenite and ferritic structural constituents can be removed.

Automotive industry is constantly interested in building cars made of light and high strength parts in order to reduce the emission levels, the fuel consumption and minimize the effects of a car crash. Some parts may be made of lighter materials, but the steel ones must compensate the strength needed for the car body. Research is made for finding new materials showing high strength combined with high ductility. Among them, transformation – induced – plasticity steels are of great interest, efforts being made to improve their characteristics. A new composition of such a steel is presented, its features being compared with those of three other steels of the same class and category. Optical microscopy at different magnifications is performed, together with Vickers hardness test. Structural particularities are found for each tested steel, justified by their own chemical compositions. The new steel reveals important characteristics: besides the mainly bainitic structure, it has both larger ferritic areas and amounts of retained austenite, making him proper for further study.