Influence of the Stress-strain State on the Wear Resistance of the Surface of 40Kh Steel after Discrete Electromechanica
- PDF / 2,049,073 Bytes
- 7 Pages / 594 x 792 pts Page_size
- 66 Downloads / 211 Views
INFLUENCE OF THE STRESS-STRAIN STATE ON THE WEAR RESISTANCE OF THE SURFACE OF 40KH STEEL AFTER DISCRETE ELECTROMECHANICAL TREATMENT V. A. Vynar1 and M. O. Dykha2
UDC 620.178.162.42
The stress-strain state of the surface after discrete electromechanical treatment is analyzed by the finiteelement method for various geometric schemes of locally hardened zones. It is shown that the version with cross tracks of hardening of the surface layers proves to be the optimal scheme of treatment under the condition of minimization of the stress state of the surface in the process of friction. Keywords: discrete electromechanical treatment, stress-strain state, wear resistance, structure, white layer.
The continuous protective structures on the surfaces of objects are not always capable of guaranteeing the required reliability and durability of tribojoints under the actual operating conditions. The technological procedures aimed at the creation of discrete surfaces by replacing traditional surface layers with discontinuous discrete structures enable us to get higher adhesive and cohesive properties of each section of the coating, decrease the level of residual stresses, and improve the conditions of lubrication of contact surfaces [1]. The discrete electromechanical treatment [2–3] forms a structure with given distributions of strength properties over local areas of the surface. The hardened surface is a regular discrete structure formed by elements of the white layer. The results of investigations show [1] that, by changing the structural and technological parameters of electromechanical treatment, it is possible to create discrete surface structures with the required arrangements of hardened fragments and to get the required area of the hardened surface. The main aim of the investigation of the influence of the level of residual stresses on the wear resistance is the attainment of the stress-strain state guaranteeing the optimal level of stresses under the conditions of friction [4–5]. In the present work, we analyze the influence of the mutual arrangement of elements of the white layer and the area of the surface coating on the specific features of the behavior of hardened bodies under the conditions of friction. Materials and the Method of Investigation We simulated the stress-strain state of an inhomogeneous material whose surface is reinforced with elements of the white layer with higher strength characteristics as compared with the characteristics of the matrix material under the conditions of friction. To this end, we use a finite-element model of a bar 15 × 15 × 6 mm in size. Each of its sides is represented by 30 elements. Hence, in total, the model contains 27, 000 elements. 1
Karpenko Physicomechanical Institute, Ukrainian National Academy of Sciences, Lviv, Ukraine; e-mail: [email protected] (corresponding author). 2 Khmel’nyts’k National University, Khmel’nyts’k, Ukraine. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 49, No. 3, pp. 86–91, May–June, 2013. Original article submitted February 27, 2013.
Data Loading...
