## 1 Introduction
[PERSON] and [PERSON] [14] experimentally proved that the reduction in the height roughness parameters of duplex stainless-steel specimens increases the crack corrosion resistance due to reducing the number of crack initiation places. [PERSON] et al. [15] reported that the decrease in the 3D roughness parameter via slide burnishing (SB) leads to the improvement of anticorrosive characteristics of X6 CrNiMoTi17-12-2 stainless steel. The increase in micro-hardness via surface plastic deformation [16], chemical heat treatment, or a combination of both [17], increases the sliding wear resistance of the treated surface. In most cases, the fatigue strength of metals and alloys increases as their hardness increases. The type of the introduced residual stresses in the SL and in the nearby subsurface layers strongly influence the fatigue behaviour of the corresponding metal component [18; 19; 20; 21; 22; 23; 24]. The formation of a compressive zone at a significant depth from the surface (for example, 0.8 mm) significantly increases the fatigue life. It should be noted that usually the introduction of useful residual compressive stresses in SL is accompanied by an increase in the surface micro-hardness, whereupon a synergistic effect is obtained in terms of fatigue strength. Modifying SL in correlation with the dependence 'finishing-SI-operational behaviour (OB)' is the purpose of the Surface Engineering (SE). SE was first introduced in England in the early 1970s [25]. SE is a modern direction in the applied engineering sciences, which refers to a wide range of techniques and technologies for investigation and modification of SL in order to improve the SI and thus the OB, aesthetics, and economics of components of various materials. In order to attain improvement in the OB, SE applies an integrated approach to studying the following three aspects, which are in mutual correlation: processes for finishing the components, SI, and OB (Figure 1). The intermediate (connecting) unit in this approach is the database obtained for the dependence of the SI characteristics on the manufacturing parameters of the respective finishing process. The final objective is to identify the appropriate finishing process for a given material (through a specific combination of manufacturing parameters) that provides the desired OB. Therefore, the appropriate finishing process is both at the commencement and at the conclusion of this integrated research approach when the final objective is achieved. There are known classifications of SE processes according to various characteristics [1]. Figure 2 shows a classification of SE processes, from which one can see that SB, and particularly diamond burnishing (DB), belongs to mechanical surface treatment (MST) as part of the SE processes. The MSTs are characterised by both the preservation of the chemical composition and the mass of the processed workpiece as well as being dominated by mechanical impact on the surface. Some researchers [10; 25; 26] include such processes as grinding and honing, in which cutting is performed, to MST. The probable reason for this inclusion is that the removed material is negligible in quantity. In order to remove such conventions, it is expedient to distinguish a subgroup from the group of MST processes: specifically, those processes in which the mass is completely conserved. These are the processes in which plastic deformation of the surface being treated takes place at a temperature lower than the recrystallization temperature for the respective material, i.e., surface cold working (SCW) processes. SCW processes are divided into two main groups: dynamic and static. The dynamic methods precede the static methods. In 1871, [PERSON] invented the sand blasting process [27], which is the predecessor of today's dynamic shot peening process in all its variants. The first patent for a static process was published in 1916 [28]. Static SCW processes (burnishing processes) are particularly suitable for rotary surfaces.