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

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1551
Author(s):  
Alexander Metel ◽  
Tatiana Tarasova ◽  
Evgenii Gutsaliuk ◽  
Roman Khmyrov ◽  
Sergei Egorov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Linear Thermal Expansion ◽  
Thermochemical Treatment ◽  
Spheroidal Graphite ◽  
Corrosion Resistant ◽  
Ion Plasma ◽  
Composition And Structure ◽  
Stage 1

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.

scholarly journals Use of plasma nitriding to improve the wear and corrosion resistance of 18Ni-300 maraging steel manufactured by selective laser melting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Godec ◽  
B. Podgornik ◽  
A. Kocijan ◽  
Č. Donik ◽  
D. A. Skobir Balantič
Keyword(s):  
Corrosion Resistance ◽  
Maraging Steel ◽  
Selective Laser Melting ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Solution Treatment ◽  
Thermochemical Treatment ◽  
Laser Melting ◽  
Wear And Corrosion ◽  
Wear And Corrosion Resistance

Abstract18Ni-300 maraging steel manufactured by selective laser melting was plasma nitrided to improve its wear and corrosion resistance. The effects of a prior solution treatment, aging and the combination of both on the microstructure and the properties after nitriding were investigated. The results were compared with conventionally produced 18Ni-300 counterparts subjected to the same heat- and thermo-chemical treatments. The plasma nitriding was performed under the same conditions (temperature of 520 °C and time of 6 h) as the aging in order to investigate whether the nitriding and the aging could be carried out simultaneously in a single step. The aim of this work was to provide a better understanding of the morphology and chemical composition of the nitrided layer in the additive-manufactured maraging steel as a function of the prior heat treatments and to compare the wear and corrosion resistance with those of conventional maraging steel. The results show that nitriding without any prior aging leads to cracks in the compound layer, while nitriding of the prior-heat-treated additive-manufactured maraging steel leads to benefits from the thermochemical treatment in terms of wear and corrosion resistance. Some explanations for the origins of the cracks and pores in the nitride layers are provided.

scholarly journals HARDNESS OF NITRIDED LAYERS TREATED BY PLASMA NITRIDING

2020 ◽  
Vol 27 ◽  
pp. 53-56
Author(s):  
Zdeněk Joska ◽  
Zdeněk Pokorný ◽  
Jaromír Kadlec ◽  
Zbyněk Studený ◽  
Emil Svoboda
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Stainless Steels ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Aisi 316L ◽  
Aisi 304 ◽  
Measurement Surface

Stainless steels, particularly the austenitic stainless grades are widely used in many industries due to good corrosion resistance, but very poor mechanical properties as surface hardness and wear resistance limit its possible use. Plasma nitriding is one of the few ways to increase the surface hardness of these steels, even though this will affect its corrosion resistance. This paper focuses on the description of the mechanical properties of nitrided layers in the two most widespread austenitic stainless steels AISI 304 and AISI 316L. The microstructure and properties of nitrided layers were evaluated by metallography and microhardness measurement. Surface properties of nitrided steels were characterized by Martens hardness. The results show that plasma nitriding created very hard nitrided layers with thickness about 40 μm and microhardness about 1300 HV0.05. Surface hardness measurements have shown that the maximum values for both steels are about 8.5 GPa, but have different behaviour under higher loads, when the AISI 316L nitrided layer began to crack on the surface and sink.

Thermal Stability of Nitrogen Expanded Austenite Formed by Plasma Nitriding on AISI304 Austenitic Stainless Steels

2008 ◽  
Vol 373-374 ◽  
pp. 308-311 ◽  
Author(s):  
Liang Wang ◽  
Yang Li ◽  
Yi Zuo Wang
Keyword(s):  
Phase Composition ◽  
Annealing Temperature ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Xrd Analysis ◽  
304 Stainless Steel ◽  
Composition And Structure ◽  
Expanded Austenite

The effect of thermal annealing temperature on the microstructure and phase composition of nitrided layer formed on AISI 304 stainless steel by plasma nitriding were investigated. The phase composition and structure of the nitrided have been analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD analysis of nitrided samples at 420oC showed the presence of γN phase in the nitrided layer. The temperature at which the nitrogen expanded austenite started to decompose was about 450oC. Above this critical temperature the γN phase transformed into a mixture of CrN and α-phase. The surface hardness of nitrided layer also slightly changed with annealing temperature.

scholarly journals Effect of Active Screen Plasma Nitriding on Mechanical Properties of Spheroidal Graphite Cast Iron

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 412
Author(s):  
Yasuhiro Hoshiyama ◽  
Keisuke Chiba ◽  
Tomoki Maruoka
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Fatigue Strength ◽  
Treatment Time ◽  
Plasma Nitriding ◽  
Nitride Layer ◽  
Spheroidal Graphite ◽  
Active Screen Plasma Nitriding ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

Spheroidal graphite cast iron is a material with a wide range of uses such as in automobile parts. By applying active screen plasma nitriding (ASPN) treatment, the use of spheroidal graphite cast iron is expanded, and it can be expected to be used under special load conditions. In this study, we evaluated the effect of ASPN treatment on the mechanical properties of spheroidal graphite cast iron. With ASPN treatment, a nitride layer was formed on the sample surface and a diffusion layer was formed further inside the nitride layer. The thickness of nitride layer increased as the treatment temperature increased. The hardness was improved by ASPN treatment. The abrasion resistance was improved by ASPN treatment, and longer treatment time resulted in higher abrasion resistance. The fatigue strength was improved by ASPN treatment, and longer treatment time resulted in higher fatigue strength. ASPN treatment also improved the corrosion resistance.

scholarly journals INFLUENCE OF SURFACE PRE-HEATING ON THE NITRIDING DEPTH OF STEEL 25CrMoVA USED COMPLEX ION-PLASMA TREATMENT

2021 ◽  
pp. 115-121
Author(s):  
V.A. Belous ◽  
Yu.A. Zadneprovskiy ◽  
I.S. Domnich
Keyword(s):  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Heated Surface ◽  
Spectral Energy ◽  
Thermal Heating ◽  
Additional Increase ◽  
Preliminary Heating ◽  
Ion Plasma ◽  
Energy Dispersive Microanalysis ◽  
Complex Ion

In the method of nitriding elements, various methods of their thermal heating are used. The simplest heating method in ion-plasma nitriding is heating by bombarding the surface first with low-energy gas ions and then with metal ions with energies up to several kiloelectronvolt. Elements exposed to ion bombardment have a welldeveloped surface that is free from contaminants and facilitates the diffusion of nitrogen into the depth of the metal during nitriding. The paper studies the effect of various preliminary heating methods on the nitriding depth in the complex ion-plasma hardening technology of 25CrMoVA steel. A JSM 7000-1F scanning electron microscope equipped with an X-ray spectral energy dispersive microanalysis attachment was used to diagnose changes occurring on the surface of the samples and at depth; the hardness was measured using a Nanoindentor G200 device. The preliminary heating of the samples was carried out both with the use of bombardment with Ti or Mo ions, and without its direct effect on the heated surface. In the experiment, differences in the depth of hardening of the nitrided layer of steel are observed when it is heated in different ways. When bombarded with Mo ions, the greatest depths of hardening were obtained in comparison with other preliminary heating conditions. It is shown that these differences are associated with the features of the morphology of the steel surface formed as a result of sputtering processes. The formation of nitride compounds in its surface layer can serve as a barrier that slows down the penetration of nitrogen into the metal. It is shown that with complex treatment in the process of deposition of a nitride coating on the surface of nitrided steel, an additional increase in the depth of hardening of the nitrided layer occurs.

scholarly journals Controlled thermogasocyclic nitriding processes

2021 ◽  
Vol 13 (S) ◽  
pp. 13-20
Author(s):  
Irina S. BELASHOVA ◽  
Peter S. BIBIKOV ◽  
Alexander A. OREKHOV ◽  
Eduard I. STAROVOITOV
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Diffusion Layer ◽  
Nitrided Layer ◽  
Physical And Mechanical Properties ◽  
New Method ◽  
Control Panel ◽  
Nitriding Time ◽  
Composition And Structure ◽  
Working Volume

The existing basic nitriding methods do not exploit many of the potential opportunities. To intensify it and increase its efficiency, this paper considers and proposes a new method of low-temperature nitriding, which makes it possible to optimise the classical process and reduce the consumption of ammonia from 2 to 10 times, reduce the nitriding time by 4-6.5 times with an increase in the thickness of the diffusion layer by 2-6 times without reducing the physical and mechanical properties. During the experiment, gas-cyclic and thermogasocyclic nitriding of armco iron was carried out on an experimental setup, which included a system for monitoring and maintaining the temperature in the working volume, a gas supply system, monitoring the flow rate and degree of ammonia dissociation, cleaning and drying gas, as well as two electromagnetic gas valves controlled from the control panel, allowing the processes to be carried out automatically. As a result, a new method of low-temperature nitriding has been developed – under the conditions of a thermo-gas cycle. This method consists in periodic alternation of saturation cycles during flow nitriding and resorption of the nitrided layer with the maximum possible decrease in the saturating capacity of the atmosphere. The proposed new method of thermogasocyclic nitriding is a new, effective hardening technology that allows to reduce the consumption of saturating gas and emissions into the atmosphere by up to 10 times, the nitriding time by 4-6.5 times, and also to increase the thickness of the diffusion layer by 2-6 times without reducing the physical and mechanical properties. A new technological parameter has been established – the duration of half-cycles, which allows simply and effectively regulating the phase composition and structure of the layer in order to obtain the required physical and mechanical properties.

Use of Plasma Nitriding to Improve the Wear and Corrosion Resistance of 18Ni-300 Maraging Steel Manufactured by Selective Laser Melting

2020 ◽  
Author(s):  
Matjaž Godec ◽  
Bojan Podgornik ◽  
Aleksandra Kocijan ◽  
Črtomir Donik ◽  
Danijela Skobir Balantič
Keyword(s):  
Corrosion Resistance ◽  
Maraging Steel ◽  
Selective Laser Melting ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Solution Treatment ◽  
Thermochemical Treatment ◽  
Laser Melting ◽  
Wear And Corrosion ◽  
Wear And Corrosion Resistance

Abstract 18Ni-300 maraging steel manufactured by selective laser melting was plasma nitrided to improve its wear and corrosion resistance. The effects of a prior solution treatment, aging and the combination of both on the microstructure and the properties after nitriding were investigated. The results were compared with conventionally produced 18Ni-300 counterparts subjected to the same heat- and thermo-chemical treatments. The plasma nitriding was performed under the same conditions (temperature of 520 °C and time of 6 hours) as the aging in order to investigate whether the nitriding and the aging could be carried out simultaneously in a single step. The aim of this work was to provide a better understanding of the morphology and chemical composition of the nitrided layer in the additive-manufactured maraging steel as a function of the prior heat treatments and to compare the wear and corrosion resistance with those of conventional maraging steel. The results show that nitriding without any prior aging leads to cracks in the compound layer, while nitriding of the prior-heat-treated additive-manufactured maraging steel leads to benefits from the thermochemical treatment in terms of wear and corrosion resistance. Some explanations for the origins of the cracks and pores in the nitride layers are provided.

scholarly journals Investigation of formation of hardened layer on titanium alloys by the method of ion-plasma nitriding

2019 ◽  
Vol 64 (1) ◽  
pp. 25-34
Author(s):  
I. L. Pobol ◽  
I. G. Oleshuk ◽  
A. N. Drobov ◽  
Sun Feng ◽  
Wang Lin
Keyword(s):  
Corrosion Resistance ◽  
Friction Coefficient ◽  
Titanium Alloys ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Saturation Pressure ◽  
Hardened Layer ◽  
Technological Parameters ◽  
Ion Plasma ◽  
Increase Wear Resistance

 Various methods are applied in the world practice to increase wear resistance, fatigue strength and corrosion resistance of aviation equipment, machinery and medicine parts made of titanium and its alloys. Ion-plasma nitriding provides the ultimate effect making it possible to obtain hardened layers with hardness of HV0.01 650–1000 with a thickness of 0.07–0.20 mm for 3–6 hours, depending on the grade of the titanium alloy.Technological factors effecting on the efficiency of ion-plasma nitriding of materials are the process temperature, duration of saturation, pressure, composition and flow rate of the working gas mixture. The effect of these technological parameters on the microstructure, microhardness and depth of hardened layers is investigated in the work. It is shown that hardness and depth of the nitrided layer can be controlled by changing the composition, volume and periodicity of the gaseous medium (nitrogen and argon) supply at the stages of heating and holding time of the samples from titanium and its alloys under ion-plasma nitriding. The tribological characteristics of titanium alloys as-received and the same ones subjected to ion-plasma nitriding under friction conditions without a lubricant were studied. For VT1-0 and VT6 alloys in the as-received state during the tests there is a monotonous decrease of the friction coefficient from 0.35–0.40 to 0.25, after nitriding the friction coefficient monotonically increases from 0.14 up to 0.30 when removing the hardened layer.Studies of corrosion resistance of titanium VT1-0, carried out in a 10 % solution of sulfuric acid, showed that after ion-plasma nitriding at a temperature of 830 °C for 6 hours, the corrosion resistance increases, as the positive polarization potential of the sample shows.

REMANIT 4439

Alloy Digest ◽  
1993 ◽  
Vol 42 (11) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Stainless Steels ◽  
Crevice Corrosion ◽  
Heat Treating ◽  
Corrosion Resistant Steel ◽  
Resistant Steel ◽  
Low Carbon ◽  
Corrosion Resistant ◽  
Mechanical Properties And Corrosion

Abstract REMANIT 4439 is a highly corrosion resistant steel with low carbon content, an addition of nitrogen to enhance both mechanical properties and corrosion resistance, and higher molybdenum than most stainless steels to resist pitting and crevice corrosion in chloride media. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-556. Producer or source: Thyssen Stahl AG.

Sign in / Sign up

Export Citation Format

Share Document