Electrolyte-plasma surface hardening of hollow steel applicator needles for point injection of liquid mineral fertilizers

Abstract

<abstract> <p>This paper presents the results of research on the effect of electrolyte-plasma hardening on tribological and mechanical properties of hollow needles of 12Kh18N10Т steel applicators for liquid fertilizer application. For the application of liquid fertilizers for processing and testing, the hollow needles of the applicator are made of 12Kh18N10Т steel of cylindrical shape with a diameter of 20 mm. To ensure uniformity of the hardening process, the part was rotated clockwise during the entire procedural cycle. To reveal the influence of the sample rotation speed on the uniform surface hardening, an experiment was conducted for three applicators with rotation speeds of 4, 6, and 8 rev/min. As a result of electrolyte-plasma surface hardening (EPSH), the phase composition of the specimen's surface is characterized by the presence of austenite (γ-Fe) and ferrite (α-Fe). It is revealed that the maximum value of microhardness after EPSH is 2 times higher than the initial value. According to the results of the performed works, the contract on application of tests in field conditions and revealing of perspectivity of needle applicators for liquid fertilizers application was concluded.</p> </abstract>