A new method of low-temperature cementation of stainless steel by decomposition of C2H2 in low-energy electron beam generated plasma

Abstract

The method of low-temperature (400-500?C) cementation of AISI430 stainless steel by decomposition of acetylene in a wide (100 cm2) low-energy (200-300 eV) electron beam generated plasma in an Ar+C2H2 gas mixture was investigated. The composition of a beam Ar+C2H2-plasma is investigated and it is shown that the degree of decomposition of acetylene varies with the current and energy of the electron beam. It is shown that the magnitude of the flow of acetylene significantly affects the formation rate and hardness of the hardened layer. From the obtained results it can be seen that at fixed values of argon pressure ( ∼ 0.8 mTorr), beam current (3.5 A), bias voltage (-120 V), sample temperature (500?C) and exposure time (3 h) increase in QC2H2 from 1 to 4-5 cm3•min-1 leads to an increase in the thickness and microhardness of the hardened layer. With a further increase in QC2H2, an abrupt decrease in the rate of formation of the hard layer occurs. © 2019 IOP Publishing Ltd. All rights reserved.