Structural Steel Microhardness Improvement by Ion Nitriding

This study developed a technological process of vacuum thermocyclic plasma nitriding, which improves the diffusion saturation rate and reduces energy consumption. The nitriding was carried out in a mixture of nitrogen and argon (25% N 2 +75% Ar) for specimens from 18KhGT steel in the temperature ran...

Full description

Saved in:
Bibliographic Details
Published in:Strength of materials 2022-09, Vol.54 (5), p.819-824
Main Authors: Dolgov, N. A., Rutkovskyi, A. V.
Format: Article
Language:English
Subjects:
Argon
Characterization and Evaluation of Materials
Chemistry and Materials Science
Chromium manganese steels
Classical Mechanics
Diffusion layers
Diffusion rate
Energy conservation
Energy consumption
Hardness
Ion nitriding
Materials Science
Mathematical models
Microhardness
Plasma physics
Process parameters
Saturation
Solid Mechanics
Steel, Structural
Structural steels
Surface layers
Vacuum chambers
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This study developed a technological process of vacuum thermocyclic plasma nitriding, which improves the diffusion saturation rate and reduces energy consumption. The nitriding was carried out in a mixture of nitrogen and argon (25% N 2 +75% Ar) for specimens from 18KhGT steel in the temperature range of 450–550 °C, pressure 50–100 Pa. The process duration ranged from 3 to 9 h. After nitriding, microhardness was evaluated. The study of 18HGT steel with a hardened nitrided layer allowed us to obtain experimental results to determine the regularity of the influence of diffusion saturation parameters on microhardness. The surface layer characteristics are determined, and the possibility of controlling them due to changes in the technological process parameters is shown. Based on the obtained experimental data, a mathematical model of the technological process of vacuum thermocyclic plasma nitriding of 18HGT steel was developed. Based on the mathematical model built on the results of experimental studies, the response surfaces of microhardness, which depend on the duration of the diffusion saturation process, process temperature, and pressure in the vacuum chamber, were created. A generalization of experimental studies of the formation of nitrided layers was carried out, which allowed us to determine the influence of technological modes of vacuum thermocyclic plasma treatment on the microhardness of 18HGT steel. The choice of optimal technological modes allowed us to increase the microhardness from 670 to 1100 kg/mm 2 .
ISSN:0039-2316
1573-9325
DOI:10.1007/s11223-022-00458-4