Possibilities of Additive Technologies for the Manufacturing of Tooling from Corrosion-Resistant Steels in Order to Protect Parts Surfaces from Thermochemical Treatment

Alexander Metel,Sergei Egorov,Tatiana Tarasova,Evgenii Gutsaliuk,Sergey Grigoriev,Roman Khmyrov

doi:10.3390/met11101551

Abstract

The structure and physical–mechanical properties of products made from powders of corrosion-resistant steel 12X18H10T by the laser-beam powder bed fusion (LB-PBF) and subsequent ion-plasma nitriding in the work were investigated. Comparative studies of the physical mechanical properties of specimens made by the LB-PBF and conventional method from steel of the same grade were carried out. The density of the specimens and the coefficient of linear thermal expansion (CLTE) after the LB-PBF are almost the same as those of the conventionally manufactured specimens. Our analysis of the obtained dilatograms in the temperature range from 20 to 600 °C showed that the CLTE of steel after the LB-PBF is within acceptable limits (18.6 × 10−6 1/°C). Their hardness, tensile strength, yield strength and elongation are higher than those of a conventionally manufactured specimen. The phase composition and structure of specimens of steel 12X18H10T made by the LB-PBF after the process of ion-plasma nitriding were investigated. The obtained results show that the mode of ion-plasma nitriding used in this case (stage 1—570 °C for 36 h; stage 2—540 °C for 12 h) does not lead to deterioration of the characteristics of the selected steel. A technological process for the manufacture of modified tooling from 12X18H10T steel by the LB-PBF was developed. It protects the surfaces that are not subject to nitriding and makes it possible to obtain a uniform high-quality nitrided layer on the working surface of the part made from spheroidal graphite iron.

Highlights

Additive manufacturing is defined as the process of coupling materials to create objects from 3D model data, layer by layer
Additive manufacturing (AM) makes it possible to create products of complex shapes that cannot be manufactured by conventional methods
One of the most promising areas of AM is the manufacturing of products from metal powders by the laser beam powder bed fusion (LB-PBF) and direct metal deposition (DMD) [2,3,4,5]

Summary

Introduction

Additive manufacturing is defined as the process of coupling materials to create objects from 3D model data, layer by layer. It is opposed to “subtractive” manufacturing methods, such as traditional machining [1]. Additive manufacturing (AM) makes it possible to create products of complex shapes that cannot be manufactured by conventional methods. AM makes it possible to reduce the time between the drawing and the final product, reduce the production time of the product, reduce material consumption and shorten the technological cycle by reducing the number of operations. One of the most promising areas of AM is the manufacturing of products from metal powders by the laser beam powder bed fusion (LB-PBF) and direct metal deposition (DMD) [2,3,4,5]. The range of materials used is expanding, along with the widespread use of corrosion-resistant steels; research is underway to determine the optimal parameters for the manufacture of products such as ceramics, metal alloys and composite materials [6,7,8]

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Results