Development of design methodology of technological process of ball-rod hardening with account for formation of compressive residual stresses

Introduction. The study results on the multicontact shock-vibrating machining using a ball-rod hardener are presented. Methods of surface plastic deformation processing, their advantages are described. The tool circuit diagram is given. Features, technological advantages, and the application area of the ball-rod hardening are specified.

Materials and Methods. When conducting theoretical studies on the processing, factors, which affect the quality of the surface layer of the machined parts, were established. Dependences are given for calculating the surface roughness, the hardened layer depth, and the deformation ratio under ball-rod hardening. While studying the generation of residual stresses, the dependence for calculating the residual stresses generated in the surface layer of the machined part was specified.

Results. The experimental findings of the processing requisite for verification of the adequacy of the theoretical models, as well as the routine of the experiments, are presented. A table and graphs clearly confirming good convergence of the theoretical and experimental data are given (the difference does not exceed 20%). Residual stresses in the surface layer are compressive which enables to predict high performance properties of the machined parts. The value of residual stresses on the workpiece surface is in the range of 130÷200 MPa. The depth of compressive residual stresses is in the range of 0.9-1 mm. The fatigue characteristic variation, the ultimate stresses of the cycle in depth, which affects the endurance limit, is calculated. It has been established that the processing of workpieces by a ball-rod hardener provides increasing the ultimate cycle stress under repeated loading by 27-35%.

Discussions and Conclusions. The design methodology of technological process of ball-rod hardening can be used under the development of production at the machine-building enterprises. In accordance with the recommendations, the limits of the required quality parameters of the workpiece surface layer are set; the parameters of the ball-rod hardener, the interference fit and the radius of rod sharpening are selected. Quality parameters of the surface layer are calculated. Correction of the selected modes and re-calculation of the parameters of the machined surface are carried out until all the specified characteristics are located within the required limits.

1. Tamarkin MA, Shcherba LM, Tishchenko EE. Proektirovanie tekhnologicheskikh protsessov vibroudarnoi otdelochnoi obrabotki shariko-sterzhnevym uprochnitelem [Design of technological processes for vibro-impact finishing treatment with a ball-rod hardener]. Strengthening Technologies and Coatings. 2005;7:13–20. (In Russ.)

2. Tamarkin MA, Chukarin AN, Isaev AG. Obespechenie akusticheskoi bezopasnosti tekhnologicheskogo protsessa obrabotki shariko-sterzhnevym uprochnitelem ploskikh detalei pri dostizhenii zadannykh parametrov poverkhnostnogo sloya [Ensuring acoustic safety of technological processing with a ball-rod reinforcer of flat details at achievement of the set blanket parameters]. Naukovedenie. 2016;6:28–35. (In Russ.)

3. Kopylov YuR. Dinamika protsessov vibroudarnogo uprochneniya: monografiya [Dynamics of vibro-impact hardening processes: monograph]. Voronezh: IPTs “Nauchnaya kniga”; 2011. 568 p. (In Russ.)

4. Shvedova AS. Povyshenie ehkspluatatsionnykh svoistv detalei pri obrabotke dinamicheskimi metodami poverkhnostnogo plasticheskogo deformirovaniya: dis. …kand. tekhn. nauk [Improving the operational properties of parts during processing by dynamic methods of surface plastic deformation: Cand.Sci. (Eng.) diss.]. Rostov-on-Don; 2016. 144 p. (In Russ.)

5. Tamarkin MA, et al. Povyshenie kachestva poverkhnostnogo sloya i bezopasnosti protsessa pri obrabotke detalei shariko-sterzhnevym uprochneniem [Improving the surface layer quality and process safety during the treatment of parts by ball-hardening]. Vestnik of P.A. Solovyov Rybinsk State Aviation Technical University. 2017;2(41):82–88. (In Russ.)

6. Tamarkin MA, Tishchenko EE, Shvedova AS. Optimization of Dynamic Surface Plastic Deformation in Machining. Russian Engineering Research. 2018;38(9):726—727.

7. Tamarkin MA, Shvedova AS, Tishchenko EE. Optimizatsiya protsessov obrabotki detalei dinamicheskimi metodami poverkhnostnogo plasticheskogo deformirovaniya [Optimization of parts processing by dynamic methods of surface plastic deformation]. STIN. 2018;3:26–28. (In Russ.)

8. Tamarkin MA, Shvedova AS, Tishchenko EE. Uvelichenie zhiznennogo tsikla detalei pri obrabotke dinamicheskimi metodami poverkhnostnogo plasticheskogo deformirovaniya [Increase in the life cycle of products when processing parts by dynamic methods of surface plastic deformation]. Contemporary Technologies in Automation. 2018;72(9):403–408. (In Russ.)

9. Tamarkin MA, Shvedova AS, Tishchenko EE. Metodika proektirovaniya tekhnologicheskikh protsessov obrabotki detalei dinamicheskimi metodami poverkhnostnogo plasticheskogo deformirovaniya [Methodic of technological processes designing of parts processing by dynamic methods of surface plastic deformation]. Vestnik Mashinostroeniya. 2018;4:78–83. (In Russ.)

10. Tamarkin MA, et al. Background technology of finish-strengthening part processing in granulated actuation media. Advances in Intelligent Systems and Computing. 2019;118-123.