Vibrational-centrifugal surface strengthening of drill and casing pipes

Abstract

Purpose. Development of new constructions of devices for strengthening drill and casing pipes by surface plastic deformation, determination of constructive and technological parameters of vibrational-centrifugal strengthening of long-length parts. Methodology. Based on the theory of static similarities of fatigue failure, methods for defining decreased mass and consumption of materials for cylindric parts as a result of effective strengthening of their outer and inner cylindricshaped surfaces by vibrational-centrifugal treatment are suggested. findings. Based on the experience of industrial use of vibrational-centrifugal treatment for strengthening plane wheel hubs and flanges, new constructive schemes of genuine devices for strengthening drill and casing pipes of exploration wells have been developed. To and durability of drill and casing pipes of exploration wells and to, The vibrational-centrifugal strengthening treatment is expedient to use during the final stage of pipes production with the purpose of increasing their reliability as well as decreasing their mass. This strengthening technology belongs to the group of dynamic methods of surface plastic deformation, features ability to dissipate considerable energy of deformation of strengthened part material in its surface layers which is equal to that of stamping. For parts made of construction steel, the vibrational-centrifugal strengthening treatment provides for the thickness of the strengthened layer within 0.15-0.20 mm, formation of residual compressive stresses of high gradient, enhanced micro-hardness. Due to technological use of considerable inertial forces of massive strengtheners, which are rolled over the surface during the strengthening process, effective reinforcement of metal of the surface processed and formation of residual stress in their metal thickness are provided. This effective strengthening of both inner and outer long surfaces allows decreasing the mass of long-length steel parts by 15-20 %. This provides for certain economic effect related to cost of part material. For the first time, structural schemes of equipment for strengthening outer and inner cylindric-shaped surfaces of long-length parts through vibrational-centrifugal treatment have been described, including those for drill and casing pipes. The suggested constructions of strengthening equipment have a simple constructive design, do not require first line maintenance workers, and are effective and energy-efficient. Originality. The developed designs of devices for strengthening long outer and, particularly, inner surfaces of cylindric long-length parts have no comparable counterparts internationally. Due to these designs, the spheres of effective use of surface strengthening increase considerably. Practical value. Material capacity of long-length parts strengthened by the suggested design of strengthening equipment decreases. On a 2-3-kilometer exploration well, the decrease in the drill string mass by 15-20 % as a result of strengthening treatment will allow saving about 30-...

Increasing the durability of cylindrical parts of wheelcarms of railway

“…У створених на використанні явища вібраційного підтримування обкочувального руху вібромашинах для зміцнення поверхні циліндричних деталей у якості масивних тіл, що співвдаряються між собою в процесі зміцнювальної обробки, слугували оброблювана деталь та вібруючий контейнер. Їх ударний контакт при цьому здійснювався через обмежену кількість сталевих кульок, які у процесі вібрацій самовилаштовувалисть вздовж твірної зміцнюваної поверхні [9,10,11]. Ефективність такої зміцнювальної обробки була доволі високою.…”

Equations of motion of masses of the Chelomey pendulum model

“…Певним варіантом подолання цих труднощів могло б бути використання для зміцнювальної обробки стволів гармат зміцнювальних пристрої для обробки внутрішніх поверхонь обсадних труб бурильних колон. Опис конструкцій цих зміцнювачів приведено у роботах [10,11]. Однак ці зміцнювачі не придатні для зміцнювальної обробки протяжних внутрішніх поверхонь, які обмежені незначними діаметрами, що властиво стволам артилерійських гармат.…”

“…А оскільки ударний контакт відбувається через обме-жену кількість деформівних тіл, у матеріалі зміцнюваної деталі формуються значні контактні напруження. Завдяки цьому забезпечуються значний ступінь зміцнення та формування у товщі матеріалу оброблюваної поверхні залишкових напружень стиску високого градієнту [11].…”

Development of a technology for the surface strengthening of barrel channels in the large-caliber artillery guns

“…An option for overcoming these difficulties could be those strengthening devices that are used for treating the internal surfaces of casing pipes for drill strings. That was the very approach suggested in papers [10,11]. However, the designs of these reinforcers are not suitable for the treatment of long inner surfaces, which are confined to small diameters that are inherent to the barrels of artillery guns.…”

“…Owing to this, significant contact stresses form in a material of the strengthened part. In this case, a high degree of hardening and the formation of residual compression stresses of high gradient are ensured [11].…”