Investigation of tribological behaviour of plasma paste boronized of AISI 8620, 52100 and 440C steels (original) (raw)
Related papers
Characterization, Tribological and Mechanical Properties of Plasma Paste Borided AISI 316 Steel
Transactions of the Indian Institute of Metals, 2017
The AISI 316 steel was treated by the plasma paste boriding by using a gas mixture of 70%H 2-30%Ar with a boron source of 100% B 2 O 3 in the temperature range of 700-800°C for 3, 5 and 7 h. The boride layers formed on the samples were observed by scanning electron microscope. The iron borides were also identified by the use of an X-ray microanalyzer, equipped with energy dispersive X-ray spectroscopy. The XRD analysis was carried out to identify the iron and metallic borides present inside the boride layer. Based on the kinetic data, the value of boron activation energy for the AISI 316 steel was estimated as 118.12 kJ mol-1 and compared with the data available in the literature. A regression model based on ANOVA analysis was used to predict the boride layers' thicknesses depending on the boriding parameters: the treatment time and the boriding temperature. A good correspondence was obtained between the experimental values and those predicted by the regression model. Furthermore, the wear behavior of the sample borided at 750°C for 5 h was investigated. The significant increase in wear resistance of plasma borided layer was observed in comparison with the untreated AISI 316 steel. The nanomechanical properties of the sample, plasma paste borided at 700°C for 7 h, were examined using the nanoindenter with a Vickers diamond tip. The load-displacement curves, as well as, Young's moduli and hardness were shown for the selected measurements. The obtained results depended on the phase composition of the tested area.
Materials Today: Proceedings, 2019
The tribomechanical behavior of AISI 8620 steel treated by different plasma-aided processes was investigated. In this study, we compared conventional plasma nitriding (CPN), pulsed plasma nitriding (PPN), plasma nitrocarburized (PNC), plasma oxynitriding (PON), and low-temperature plasma blued (LTPB). The microstructure of treated samples was characterized using X-ray diffraction, and the compound layer thickness was measured by optical microscopy. Vickers microhardness profiles were correlated with a reduction of friction coefficient in the treated samples. Wear test was performed on a pin-on-disc tribometer in dry-sliding conditions using a counter-face of WC-Co ball. Wear tracks on the ball and surface of the treated sample was analyzed with optical micrographs. LTPB process shows the best reduction of the friction coefficient of the amorphous carbon layer on the top of the surface.
Moving parts that are essential to life are subject to wear and friction. Coatings, lubrication and heat treatment are some operations conducted to reduce these effects and prolong part life. Plasma Transferred Arc coating is an important coating method for hard coating. It is used in various industrial applications such as automotive valves, glass and ceramic molds and plastic extrusion dies. In PTA powder content that is used for coating is an important point of research. In this study microstructure and wear behavior of AISI 4140 steel surface coated by Boron Carbide was inspected. Ekabor II powder that contains Boron Carbide was mixed with a Nickel base to produce coating powder. Wear tests were conducted on a Ball-on- Disk device with circular geometry. Optical Microscopy was used to characterize microstructure of coating layer formed on the surface of AISI 4140. It was found that although Boron Carbide content has positive improvements these improvements lessen after 10% Ekabor by weight in coating.
Plasma paste boronizing of AISI 8620, 52100 and 440C steels
Materials & Design, 2011
In the present study, AISI 8620, 52100 and 440C steels were plasma paste boronized (PPB) by using 100% borax paste. PPB process was carried out in a dc plasma system at temperature of 700 and 800°C for 3 and 5 h in a gas mixture of 70%H 2-30%Ar under a constant pressure of 4 mbar. The properties of boride layer were evaluated by optical microscopy, X-ray diffraction and Vickers micro-hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed FeB and Fe 2 B phases for 52100 and 8620 steels and FeB, Fe 2 B, CrB and Cr 2 B borides for 440C steel. PPB process showed that since the plasma activated the chemical reaction more, a thicker boride layer was formed than conventional boronizing methods at similar temperatures. It was possible to establish boride layer with the same thickness at lower temperatures in plasma environment by using borax paste.
Plasma transferred arc boriding of a low carbon steel: microstructure and wear properties
Applied Surface Science, 2002
Borided coatings on AISI 1018 steel with different boron contents were produced using plasma transferred arc (PTA) melting. The thickness of the coatings ranged from 1 to 1.5 mm and their hardness from 400 to 1600 HV. Hypoeutectic or hypereutectic compositions consisting of primary ferrite or primary Fe 2 B borides, respectively, and a eutectic constituent of a-Fe Fe 2 B were obtained. The presence of FeB attested in coatings with the highest boron contents seems to be responsible for the intergranular cracks extending from the surface of the coatings to the substrate. Crack free coatings corresponding to the minimum quantity of eutectic and with a minor quantity of FeB were subjected to pin on disk wear testing and compared to the steel of the substrate. It was found that the wear rate of the borided coatings was about four orders of magnitude lower than the wear rate of the steel substrate. A transition from mild to severe wear was observed for the steel substrate material, but it was absent in the case of the borided coatings for the entire range of the applied loads examined. It is shown that the transition in the case of steel occurs when grooving and plastic deformation is replaced by intense cracking of the material above a critical load. In the case of the borided layer the dominant wear mechanism is delamination of the eutectic, however, the platelike borides are able to support the load and remain in the mild wear range for all the loads tested. Both borided and plain steel surfaces have the same friction coef®cient after a short transition period, because both develop an oxide layer leading roughly to the same tribosystem with the alumina counterbody.
Wear resistance increasing of boron saturated surface layer of steel 15 230 and 17 246
2010
In presented paper we described studies of resistance of selected material in abrasive wear tests. A surface of tested materials was remelted using TIG method and the layer of borax and B4C in water suspension at the surface. Based on tests results, we found out, that the B4C as a boron source is more suitable compare to borax when saturating remelting surface layer, with more significant impact on relative abrasive wear resistance of selected steel 15 230 and 17 246. Abstrakt V našom príspevku popisujeme štúdium odolnosti vybraných materiálov v skúškach abrazívneho opotrebenia. Povrchová vrstva testovaných materiálov bola pretavená metódou TIG s bóraxom a B4C vo vodnej suspenzii. Na základe výsledkov skúšok sme zistili, že B4C ako zdroj bóru je vhodnejší ako bórax pri nasycovaní pretavovanej vrstvy, s výraznejším vplyvom na pomernú oteruvzdornosť oboch vybraných ocelí 15 230 aj 17 246.
Investigation of tribological properties of boronised pure Cu journal bearings
Surface Engineering, 2010
In practice, ferrous based materials are not used because they show similar properties to shaft material and are known to cause adhesive wear in journal bearings. With boronizing process, adhesive wear can significantly be decreased. In this study, boronizing has been applied to some ferrous based (SAE 1020, TS-DDK 40) journal bearings. Wear experiments were done on SAE 1050 steel shaft as counter abrader with 100 N loads, and 1500 rpm for 5 h by using a radial journal bearing test rig. Boronizing treatment increased wear resistance of SAE 1020, TS-DDK 40 about 10-25, and 5-7 times respectively.
Kinetics of plasma paste boronized AISI 8620 steel in borax paste mixtures
Protection of Metals and Physical Chemistry of Surfaces, 2013
In the present study, AISI 8620 steel was plasma paste boronized by using various borax paste mix tures. The plasma paste boronizing process was carried out in a dc plasma system at a temperature of 973, 1023 and 1073 K for 2, 5 and 7 h respectively in a gas mixture of 70% H 2-30% Ar under a constant pressure of 10 mbar. The properties of the boride layer were evaluated by optical microscopy, X ray diffraction, the micro Vickers hardness tester and the growth kinetics of the boride layers. The thickness of the boride layers varied from 14 to 91 μm depending on the boronizing time and temperature. X ray diffraction analysis of boride layers on the surface of the steel revealed the formation of FeB and Fe 2 B phases. Depending on the temperature and layer thickness, the activation energies of boron in steel were found to be 99.773 kJ/mol for 100% borax paste.
Effect of pulse plasma nitriding on tribological properties of AISI 52100 and 440C steels
International Journal of Surface Science and Engineering, 2014
AISI 52100 and 440C bearing steels were nitrided in conventional plasma (CPN) and pulsed plasma (PPN) consisting of 0.33 and 1 N2/H2 gas ratios at temperature of 500°C for 4 h under a constant pressure of 5 mbar. The surface of nitrided steels was investigated using optical microscopy, X-ray diffraction (XRD) and microhardness. The tribological behaviour of plasma nitrided steels was studied by means of unlubricated ball-on-disc method under constant loads of 5 and 20 N, sliding speed of 0.3 m/s at room temperature. The SEM and EDS techniques were used to analyse the worn surfaces of the steels. The results showed that γ′-Fe4N and α-Fe(N) were dominant phases for pulsed plasma nitrided 52100 and 440C steels, respectively and pulsed plasma nitriding slightly improved the wear behaviour of both steels.
Wear Behavior of DIN 1.2210 Steel Modified by a Pulse Plasma Technique
Acta Physica Polonica A, 2016
The microstructure and wear properties of pulse plasma treated AISI 4140 steel was investigated. The surface properties of the materials have been improved by modifying the surfaces of the DIN 1.2210 steel with pulse plasma technique. The sample surfaces have been modified by pulse plasma with C3H8, nitrogen and O2 gases. Two different distances between the sample and nozzle and three different numbers of pulse were determined for modification process and the surface process was implemented by using tungsten electrode with 800 µF battery capacity. The optical images were taken of the materials which the surfaces were improved by using pulse plasma technique. The surface modified samples were subjected to X-ray diffraction analysis. Wear tests were performed in a linear wear test machine with 0.15 m/s constant sliding speed under 5 N loads for 200 m sliding distance. The wear rate was changed in accordance with process parameters. The wear resistance increased in the surface modified specimens was compared to that of non-modified ones. Worn surfaces of specimens were studied by scanning electron microscope and energy dispersive spectroscopy analyses techniques. It is determined that the thickness of modification layer changes regarding to the amount of new phases and sample-nozzle distance. It is approved the increase on wear resistance related to wolfram diffusion.