download PDF

DOI: 10.18503/1995-2732-2025-23-2-128-133

Abstract

Problem Statement (Relevance). Drilling pumps are widely used by enterprises of the fuel and energy complex during the development of new fields. Structurally, the drilling pump is a set of equipment. At the same time, the quality of functioning of the entire unit as a whole depends on its individual elements. One of the “weak points” in this case are cylinder units. The risk analysis carried out by the authors showed that this is the most vulnerable part of the equipment. The main reason for the failure of this unit is a violation of the performance of the cylinder liner. In this case, the liners of the cylinders of drilling pumps are most often made of two components: a liner of cast iron is pressed into a steel cage. After assembly, finishing machining is required. At the same time, the use of hardened wear-resistant cast iron reduces the efficiency of cutting. In this paper, the possibility of replacing a liner made of high-strength cast iron with a liner made of gray cast iron, which has been subjected to surface strengthening, is considered. Objectives are improving the quality of cylinder assemblies of drilling pumps based on the use of liners made of gray cast iron with a hardened layer. Methods used. The paper uses methods of experiment planning, strength calculations, qualimetric evaluation, finite element method, cutting theory. Novelty. The manufacture of wear-resistant elements is carried out using a new method of thermodiffusion hardening by heating in contact with oxides of alloying elements. This makes it possible to obtain a layer with an inverse hardness distribution on the surface of gray cast iron. A comprehensive study has been carried out, which makes it possible to replace wear-resistant cast iron with a gray reinforced layer. Result. Studies of the effect of surface strengthening of gray cast iron by heating in contact with a mixture of oxides of alloying elements on the strength and rigidity of cylinder liners of drilling pumps were carried out. As a result, it was found that these properties are comparable to high-strength cast iron. As initial data on the load, the pressure values that arise during the formation of an interference fit between the liner cage and the working part were taken. The issues of machinability by cutting are considered. The use of a liner with a grey cast iron element and a wear-resistant one is compared using the differential method. Practical Relevance. The developed finite element model makes it possible to study the interaction of elements of the cylinder liner of drilling pumps. You can change the forces and dimensions involved, as well as the geometric configuration of the parts, to expand the scope of the model. The use of the obtained results at the design stage of machine components makes it possible to improve the quality of products due to the competent selection of connection parameters. It is also possible to reduce the cost of production by using a cheaper material and reducing manufacturing costs. Preliminary recommendations for cutting modes have been received.

Keywords

quality, pump liner, cast iron, hardening, surface layer quality, technology

For citation

Nekrasov R.Yu., Ovsyannikov V.Ye., Gubenko A.S. Improving the Quality of Drilling Pump Cylinder Liners Based on the Use Of Gray Iron with a Hardened Layer. Vestnik Magnitogorskogo Gosudarstvennogo Tekhnicheskogo Universiteta im. G.I. Nosova [Vestnik of Nosov Magnitogorsk State Technical University]. 2025, vol. 23, no. 2, pp. 128-133. https://doi.org/10.18503/1995-2732-2025-23-2-128-133