|ČERNÝ Ivo||SVUM a.s.|
|Spoluautoři SÍS Jiří|
In the past, V-ROL N steel, produced at Poldi Kladno, was used for many years for a manufacture of aircraft undercarriages, particularly for quite famous small aircraft L 410 Turbolet. As a result of privatisation process in the nineties and other circumstances, the V-ROL N steel, known by its very good or even excellent properties, has not been more available. Within the recent Czech research and development project MOSTA aimed at modernisation of the L 410 Turbolet aircraft, a substitution of materials previously used became an issue. The paper contains results of an extensive experimental programme aimed at comparison of the V-ROL N steel used in the past, still available for research purposes, with another steel of a similar type, VIP P-ROL N steel, manufactured in Czech Republic. The results show that in spite of that some differences in chemical composition and some mechanical properties exist, the substituting steel has encouraging properties. A specific attention is paid to fatigue resistance, where not only comparative fatigue S-N curves are presented, but also some aspects of fatigue damaging process and mechanisms are discussed.