Kuffova M.,Academy Of The Armed Forces Of Gen M R Stefanik |
Celko P.,Alexander Dubcek University, Trencin
Kovove Materialy | Year: 2015
The presented work is focused on the fatigue endurance improvement by using plasma nitriding. In this research the microstructure and fatigue properties of low-alloyed steel 50CrV4+QT were evaluated. The low-alloyed (manganese-chromium-vanadium) steel is commonly used after heat treatment - quenching and tempering - QT(.7). This steel is widely used for highly loaded machines and parts of road vehicles: crankshafts of diesel engines, shafts of driving gears, connecting shafts, pins, springs, axle shafts and piston rods. Steel is suitable for quenching and tempering and contains chemical elements which predetermine it to the chemical-thermal treatment: plasma nitriding. The fatigue limit was determined at the rotating beam fatigue. The fatigue limit improvement at 1 × 107 cycles was 44 %. Explanation of the improvement is based on stabilized gradient of properties in treated layer. © Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Bratislava, Slovak Republic.
Stiavnicky M.,Academy Of The Armed Forces Of Gen M R Stefanik |
Lorincikova R.,Air Force Command
Advances in Military Technology | Year: 2013
The paper deals with numerical and analytical analysis of sliding wedge breech mechanism response during one shot fired from 100mm cannon. The model of the breech together with gun tube was modelled in LS-Dyna environment using available commands for mesh generation and for handling boundary conditions including contact surfaces. Only the components that significantly affect the force redistribution are modelled for the analysis. The explicit finite element method was used to retrieve stresses and deformations of the breech. The emphasis was put on the breech block which was the critical phenomenon. The numerical results were compared to analytic solution which is commonly used in the process of designing sliding wedge breech blocks. The response of the gun as a whole was also analysed.