The research presented in the current paper was carried out for the experimental steel designed for plate which meets the requirements for grade X100 according to API5L. Physical modeling of the rolling process was carried out using the GLEEBLE 3800 simulator. The tested steel is fine-grained constructional steel for making tubes for gas pipelines with the working pressure higher than 15 MPa. The fine-grained structure guarantees excellent plastic properties as well as high impact toughness. After rolling the steel should obtain the minimal yield point of 690 MPa and tensile strength over 760 MPa.

The paper presents the relationships between the topography parameters of the usable and mineral surfaces abrasive surface, obtained in various technological processes. Surface properties determine the safety of their use and the main parameters of surface topography are roughness and waviness. The basic use properties include, surface roughness and the associated coefficient of friction, expressed by the coefficient of adhesion of the vehicle wheels to the surface. Practical examples of shaping of stereometric features of surfaces with specific use properties as well as friction coefficient and wheel adhesion values as well as the generated noise intensity depending on roughness, for different types of road surfaces under different operating conditions.

The article discusses the impact of hot forging elongation operations on the closure of metallurgical discontinuities such as middle porosity in selected magnesium alloys (AZ91) depending on the shape of the input used. Numerical modeling was carried out using the Forge^®NxT 2.1 program based on the finite element method and laboratory modeling in order to bring about the closure of defects of metallurgical origin in deformed forging ingots. On the basis of the conducted research, optimal values of the main technological parameters of forging and appropriate groups of anvils to be used in individual stages of forging were proposed in order to eliminate metallurgical defects.