Development of a tool for conical thread frictional hardening and tests of its operation

Autor: I. P. Taras, L. Ya. Ropyak, T. O. Pryhorovska, M. Y. Burda, O. V. Pryhorovskyi
Rok vydání: 2020
Předmět:
Zdroj: Scientific Bulletin of Ivano-Frankivsk National Technical University of Oil and Gas.
ISSN: 2415-3524
1993-9965
DOI: 10.31471/1993-9965-2020-2(49)-25-38
Popis: The article considers the problem of designing a tool for friction hardening to increase the fatigue strength for conical threaded joints of elements of oilfield and drilling equipment. To increase the fatigue strength, a tool was developed for frictional strengthening of the working surface of the thread. The proposed design of the tool solves the current problem of simultaneous strengthening of depressions and side surfaces of the conical notch, which provides an increase in both fatigue strength and wear resistance. The design dimensions of the developed tool are determined using geometric modeling. The scientific novelty of the developed tool design is to solve the problem of simultaneous strengthening of depressions and surfaces of the conical groove profile, namely different lengths of the side surfaces of the conical groove, by modifying its lateral deforming elements. This simplifies the manufacture of the tool, increases the stability of the tool, the stability of the parameters of the reinforced layer of the working surface of the profile of the conical keyway on the elements of drill strings, and this improves the quality, productivity and efficiency of friction reinforcement of conical keyholes. Hardening was carried out on a lathe 16K20. The following hardening modes were selected: maximum rolling force - 20 kN. The maximum processing speed is 20 m / min. Experimental studies of fatigue strength on the machine IMA-50 threaded parts of oilfield equipment made of steel 40HN, reinforced with the proposed tool. During the development of the method of testing the parts for fatigue strength, a method of loading the sample according to the scheme of pure bending by rotation was adopted. It was found that the fatigue strength of reinforced parts made of 40HN steel was 1.15-1.2 times higher than the fatigue strength of non-reinforced parts made of the same material. The main factors that increase the fatigue strength of the conical threaded connection of parts have been identified.
Databáze: OpenAIRE