It is important to shape the required properties of the surface layer in the technological process. This issue is an important problem due to the ability of the kinematic pair elements to the required reliable operation of machine parts. The latest generation devices work with increasing operational loads. This forces the search forever-newer construction materials or innovative manufacturing engineering technologies that would ensure high reliability and durability of machine components. For mechanical engineering, continue to be used on steel structures of machine parts. In the petrochemical and shipbuilding industry, stainless steels are very poplars. Those materials are used in the constructions of seawater and acid installations. Currently, a newer material with more favourable properties is two-phase stainless steel. This is the so-called duplex steel. It can be applied to pump shafts in acid or seawater solutions. Duplex cast steel is a difficult-to-cut material. It is important to determine the effect of cutting parameters on the surface quality of the shafts and wear of cutting edge. Traditional methods of finishing surface treatment of shafts are machining (turning, grinding, superfinishing). Considering the possibilities of equipping a marine power plant workshop, it would be best to use machining by turning.
The paper specifies the relationship between the wear of the cutting edge and the geometrical structure of the machined surface as well as the type of tool material used and the shape of the cutting inserts.