Microalloying elements such as Ti, Nb, V, entered into steel they influence their microstructure and mechanical properties, because formation of carbonitrides, M(C,N). Influence of carbonitrides to the microstructure and mechanical properties depends on their basic stereological parameters: volume fraction, Vv, and their size, r. In this work the Cellular Automata model of the kinetics of the carbonitrides precipitation which enable to predict the image of the microstructure and calculate the size of carbonitrides formed during isothermal annealing of supersaturated steel is presented. In the high temperature the microalloying elements inhibit the austenite grains growth. Chemical composition of steel has influence to volume fraction and size of precipitations. The work is supplemented with examples of experimental comparison.

The main goal of the article is to identify artificially created defects like lack of fusion and incomplete penetration in butt weld joint using non-destructive volumetric methods. These defects are the most serious defects in welds of steel constructions from the safety point of view. For identification, an ultrasonic phased array technique and a conventional X-ray using digital imaging were used. The theoretical part of the article describes the current state of the given issue and provides basic theoretical knowledge about ultrasonic and X-ray welding tests. In the experimental part, the procedure and results of testing butt weld joint are described by both non-destructive methods. The butt weld joint was made from steel S420MC. Each indication obtained by the ultrasonic and x-ray technique is supplemented by the macrostructure of the weld taken from the indication position. The results of the experimental work mentioned in the article point to the possibility and reliability of the identification of melting defects by selected nondestructive methods in terms of their character and orientation.

The paper presents the authors’ concept of an adaptive road lighting that is concurrent with vehicles moving on roads. The lighting system is based on luminaires with light emitting diodes. The authors describe the operation of the adaptive road lighting system and point out benefits and limitations of the solution. The theoretical considerations are supported by an analysis of the installed and working system that was implemented at Bożeny street in Poznan, Poland. The system was also evaluated by the residents living near the street.