Tool Steel Research Articles

Characterization of wear and friction between X160CrMoV12 tool steel and carbon steel sheet during reciprocating sliding tests

Characterization of wear and friction between X160CrMoV12 tool steel and carbon steel sheet during reciprocating sliding tests

Synthesis of FeSi-FeAl Composites from Separately Prepared FeSi and FeAl Alloys and Their Structure and Properties.

Composites consisting of iron aluminide and iron silicide phases were studied in this work. Powders of iron aluminide and iron silicide were prepared by mechanical alloying separately. Subsequently, they were blended in three different proportions and sintered by the SPS method under various conditions. After sintering, the composites are composed of FeAl and amounts of other silicides (Fe5Si3 and Fe3Si). Ternary Fe-Al-Si phases were not determined, even though their presence was predicted by DFT calculations. This disagreement was explained by steric factors, i.e., by differences in the space lattice of the present phases. Hardness and tribological properties were measured on composites with various weight ratios of iron aluminide and iron silicide. The results show that sintered silicides with the matrix composed of iron aluminide reach comparable hardness to tool steels. The composites with higher mass ratios of iron aluminide than silicide have higher hardness and better tribological properties.

Study of the effect of asymmetric rolling followed by ion nitriding on the hardness and structure of HSS M2 tool steel

Study of the effect of asymmetric rolling followed by ion nitriding on the hardness and structure of HSS M2 tool steel

Prediction of Tool Wear in Fine Blanking Punch with PVD Coating with TiCN for JIS.SKH51 High Speed Tool Steel Using Archard Wear Model

The aim of this study is predict tool wear in the fine-blanking process using a tribometer tester with ASTM G99-17 standard. Then, the result of wear volume and tool life were confirmed with finite element simulation and experiment. The punch material used in fine blanking process was selected to be hight speed steel JIS.SKH51 with surface coating thickness 4 µm of TiCN, the work piece material was used as hot-rolled steel JIS.SPHD P/O, with a thickness of 8 mm. The experimented and simulated results were found that the pressure, and sliding velocity were increase in term of linear curve with slope K = 2.09x10-6 and K = 2.07x10-6 ,respectively, and the hardness of material was increase in term of power at 1.983 and slope of K = 2.14 x10-6. These three factors were effect to the wear volume and tool life, simultaneously, the summation of three factors will average as K = 2.10 x10-6. From comparison of the applied wear equation model with tribology tester the simulated and experimented results were similarly equal with 0.05 by significance at 95% reliability confident. The resulted were precisely confirmed according to the previous research.

In-situ directed energy deposition of Al based low density steel for automotive applications

This work deals with the fabrication of one low density steel by mixing AISI S2 tool steel and AlSi10Mg powders using powder-based directed energy deposition (P-DED) technique. Two approaches of mixing powders were compared-continuous mixing during the process (in-situ) and mixing the powder prior to the process (premixed). The P-DED sample was characterised by a variety of techniques such as optical microscopy, scanning electron microscopy, electron backscatter diffraction, X-ray diffraction, and hardness measurement. Our findings demonstrate the successful achievement of steel with a 8 wt. % AlSi10Mg addition when two dissimilar powders are premixed, resulting in approximately 12% reduction in the density of S2 steel. Optimizing the powder feed rate and the ratio of AlSi10Mg powder contribute to an improvement of printability, eliminating materials separation, leading to a homogenous deposited part. Compared to the in-situ mixing case, the premixed process within the current process window generates a more homogeneous microstructure consisting of three phases: Ferrite, Fe3Al and Fe3AlC carbide. Whereas, the in-situ sample exhibits only two phases Ferrite and Fe3Al. The hardness of the premixed sample is found to be slightly higher compared to the in-situ sample.

Enhancement of diffusive oxidation resistance and topographical corrosion resistance of hot work tool steels by nickel multifunctional coatings

This research focuses on the positive effects that a metallic coating made with Nickel coating can have on the oxidation and corrosion behaviour of hot work tool steels (HWT). Two different types of hot work tool steels, each with a distinct amount of chromium, were analysed by means of the gravimetric oxidative method and corrosion testing. Using PVD deposition techniques, Nickel coating is deposited onto the steel specimens in order to achieve tailor made properties. Investigations into the diffusive oxidation behaviour of HWT steels are carried out at temperatures of 600, 700, and 800 °C. Before and after going through the oxidation process, the surface morphologies of steel specimens are analysed using SEM and XRD instruments respectively. The initial stages of oxidation are characterized by rapid oxidation; however, as the time spent oxidising the specimens increases, the rate of oxidation slows down. As the temperature rises, the quantity of oxidation that may be tolerated drops. The ability of a specimen to resist oxidation is enhanced when it has a comprehensive uniform nickel coating. It is interesting to note that the oxidation resistance of both type HWT specimens coated by Nickel coating has increased by a factor of two. Intriguingly similar trend with three-fold increase in corrosion resistance of the aforementioned steels is achieved in red sea water when coated with Nickel.

ВИБІР ТЕХНОЛОГІЧНИХ ПАРАМЕТРІВ ЛАЗЕРА ДЛЯ ОТРИМАННЯ НАНОСТРУКТУР НА ІНСТРУМЕНТАЛЬНІЙ СТАЛІ У12А

According to the improved model of the thermal interaction of laser radiation and the processing material, a study of the change in the maximum temperature at different depths of the surface layer was carried out on the example of tool steel U12A. The rate of change of the maximum temperature and temperature stress as a function of the heat flux density of laser radiation (LV) was also studied. The range of LV density was taken within q=108...1011 W/m2 for different times of its action, which corresponds to the conditions for the possible occurrence of NS. The study of the dependence of the rate of change of the maximum temperature on U12A steel on the density of the heat flow at different depths showed that during all times of its action, rates of temperature change of more than 107 K/s are realized, which indicates that, according to this criterion, the formation of NS is possible over the entire range of densities heat flow and at all investigated depths. To determine the possibility of accelerating the formation of NS, the values of temperature stresses in the zone of action on U12A were calculated at a density of 108...1011 W/m2 at different depths with an action time of t=10-4 ...10-10c. Which showed that the direct formation of NS from the action of temperature stresses is practically impossible, however, at a time of 10-5...10-4 of their values, they approach those required at a heat flux density of 1011 W/m2. In order to determine the technological parameters that ensure the production of NS, spatial dependences of the volume of NS on the heat flux density and the time of its action were constructed for the radius of the spot R=10-6 m (Fig. 8) and R=5•107 m (Fig. 9) . It was determined that obtaining NS is more realistic for the size of the spot 5•107 m, although the probability of obtaining them is also low. In fig. 10 and 11 show similar dependences for the grain size on the heat flux density and the time of its action for the spot size R=10-6 m and R=5•107 m when acting on U12A tool steel. The obtained spatial pictures allow, knowing the required grain size, to choose the technological parameters that allow them to be implemented. All this will be required during the development of the technology for obtaining strengthening nanostructured coatings on the cutting tool.

The Role of Carbides in Forming the Steels Structure and Properties under Pulsed Laser Irradiation

Introduction. At present, in scientific publications, there is no unambiguous understanding and reasoned metal physical justification of the role of the carbide phase of irradiated materials in forming the required structure and achieving a given degree of hardening of surface layers of steels during pulsed laser treatment, especially in the zone of laser hardening from a solid (austenitic) state. The solution to this issue is of great importance, since it allows us to reasonably and purposefully design the required structure of surface layers of products of various functional purposes with high performance properties. The complexity and insufficiently detailed study of the process of structure formation in the surface layers of steels under extreme thermal effects of pulsed laser radiation required a series of metal physical experiments to study the fine structure of steels after high-speed high-temperature hardening. The aim of this article was to obtain, quantify and critically analyze the array of results of metal physical studies and to assess the degree of influence of the carbide phase on the formation of structure and properties of surface layers of steels in the process of pulsed laser hardening in different modes, that is, with and without melting the surface of the samples. Materials and Methods. In the work, carbon and alloyed tool steels were subjected to surface laser irradiation at a Kvant 16 installation. The radiation power density was 70–200 MW/m2. Optical, scanning probe and electron microscopy were used in conducting metal physical studies, as well as methods of diffractometric, spectral and durometric analysis of steels before and after laser treatment. Results. It was shown that laser treatment of steels with a radiation power density of 130–200 MW/m2 led to a local change in the chemical composition in the laser-fused areas of the spot, partial or complete dissolution of carbides present in the irradiated metal and an increase in the amount of residual austenite in the fused areas up to 40–60 %. It was found that on P6M5 steel, the maximum possible hardness of the irradiated zones was achieved by dissolving 30 % of carbides, on 9XC, HVG steels — 60–70 %. It was shown that under pulsed laser irradiation with q=70–125 MW/m2, that is, without melting the steel surface, "white zones" formed around carbide inclusions under the influence of thermo-deformation stresses at the boundaries of the "carbide – steel matrix" composition. They had irretrievability, dispersion of the structure and increased hardness (10–12 GPa). It was determined that the maximum hardness of laser-hardened metal in the zones of laser hardening from a solid state was achieved if the "white zones" occupied 40 % of the irradiated area of steel. It was found that the dispersion of carbides in this case was 0.5–1.5 microns. Discussion and Conclusion. The results of the conducted studies indicate that in order to obtain the best combination of hardness and viscosity of the irradiated zones during laser treatment with melting of the surface of steels of different chemical composition, it is necessary to dissolve different amounts of carbides. The dispersed structure of laser-fused steel zones, along with a sufficiently high content of residual austenite, predetermine the possibility of improving the operational characteristics of irradiated materials, especially under conditions of external shock loads. The analysis of the conducted metal physical studies irradiated without melting the surface of steels allows us to conclude that in order to obtain a high degree of hardening, it is necessary and expedient to ensure the presence of a certain volume of dispersed carbides in the structure of the irradiated steel. The structural composition of "white zones" formed during laser treatment without melting the steel surface contributes to obtaining a unique level of operational properties. The results of the performed studies contribute to the theory of steel structure formation under conditions of extreme heat exposure and allow for a rational choice of modes of surface laser processing of products and their operability.

The Influence of Industrial-Scale Pack-Boroding Process Time on Thickness and Phase Composition of Selected Cold-Work Tool Steels

The Influence of Industrial-Scale Pack-Boroding Process Time on Thickness and Phase Composition of Selected Cold-Work Tool Steels

Development of a multi-way coupled discrete-finite element method simulation procedure for modelling soil-passive vibration tool interaction

Among the energy-saving tillage solutions, a promising technology is the application of passive vibration-based soil tillage tools. If the appropriate tillage parameters are applied, a tillage tool which involves vibration-based motion can reduce the draught force and energy requirements of the tillage process while enhancing its quality. The main focus of our research was on developing a coupled discrete-finite element procedure to investigate the interaction between passively vibrating tools and the soil. To validate this method, a soil bin measuring system was constructed to investigate the operation of a highly rigid structural steel (S235) tool along with a more flexible polymethyl methacrylate (PMMA) tool, with the soil bin at working depths of 18, 30, and 42 mm, tool velocities between 28 and 37 mm s−1, in sandy soil with 1 ± 0.1 % dry based moisture content. Soil bin measurements with the highly rigid S235 tool were simulated using the discrete element method (DEM) along with a coupled discrete-finite element (DEM-FEM) procedure, while the soil bin measurements applying the more flexible PMMA tool were simulated using the coupled DEM-FEM procedure. In the case of DEM calculations the hysteretic spring and linear cohesion contact models were applied, and in the case of FEM calculations the transient, linear elastic model was utilised with Rayleigh damping. During the parameter calibration process it was observed that the soil properties depend on depth, therefore a multi-layered soil model was created. After parameter calibration the simulated mean force and deformation values matched the measured values with less than 15 % difference. Furthermore the simulation results also supported the assumption that passively vibrating tillage tools loosen and mix the soil more effectively. Based on these results, it can be concluded that the coupled DEM-FEM procedure enabled the accurate modelling of passively vibrating tillage tools.

MiniMelt: An instrument for real-time tracking of electron beam additive manufacturing using synchrotron x-ray techniques.

The development of a sample environment for in situ x-ray characterization during metal Electron Beam Powder Bed Fusion (PBF-EB), called MiniMelt, is presented. The design considerations, the features of the equipment, and its implementation at the synchrotron facility PETRA III at Deutsches Elektronen-Synchrotron, Hamburg, Germany, are described. The equipment is based on the commercially available Freemelt ONE PBF-EB system but has been customized with a unique process chamber to enable real-time synchrotron measurements during the additive manufacturing process. Furthermore, a new unconfined powder bed design to replicate the conditions of the full-scale PBF-EB process is introduced. The first radiography (15kHz) and diffraction (1kHz) measurements of PBF-EB with a hot-work tool steel and a Ni-base superalloy, as well as bulk metal melting with the CMSX-4 alloy, using the sample environment are presented. MiniMelt enables time-resolved investigations of the dynamic phenomena taking place during multi-layer PBF-EB, facilitating process understanding and development of advanced process strategies and materials for PBF-EB.

The geometric surface structure of hardened powder tool steels after finish turning using coated and uncoated PCBN cutting tools

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Enhanced Anti-Corrosion Performance of Co-Cr-Mo Alloy in Molten Al by Prior Oxidation Treatment

Co-based alloys are promising alternatives to replace the currently used tool steels in aluminum die-casting molds for producing sophisticated products. Although the reaction is significantly less severe compared to that of tool steels, bare Co-29Cr-6Mo (CCM) alloy is still gradually corroded under molten Al, leading to the local failure of the alloy due to the formation of intermetallic compounds between the matrix and molten Al. This study indicated that prior oxidation treatment at 750 °C on CCM alloy is beneficial in enhancing the corrosion resistance of the alloy to molten Al. The is more pronounced in the alloy after a longer oxidation treatment. However, after oxidation for longer than 24 h, the protectiveness of the film cannot be enhanced anymore. In addition, even after the full failure of the oxide film, the thickness loss rate of a sample with prior oxidation treatment is much lower than that of a bare sample. This can be attributed to the fact that network-aligned oxide particles of the cone structure boundary inhibit both the outwards movements of alloying elements and the dissolution of the intermetallic layer.

Study of the behavior of skewness (Rsk) and kurtosis (Rku) parameters in the dry drilling process of Al-Mg-Si alloy 6351 T6 using a Diamond‐Like Carbon coated high-speed steel tool

Drilling is one of the most used conventional processes. The option of removing cutting fluids has gained ground in scientific studies. However, there are many problems with the cutting temperature and adhesive wear mechanism. These can be mitigated by adopting coating technology. In this study, the influence of the feed (f), cutting speed (Vc), and tool condition (with and without DLC coating) on the behavior of Rq, Rsk, and Rku roughness parameters was investigated during dry drilling of an aluminum alloy. The range of Rsk and Rku values obtained was similar to those in other studies. The significant influence of the Vc was verified in Rq and Rsk. The effect of DLC on roughness was not significant. The predominant formation of the adhesive wear mechanism was verified.

EXPERIMENTAL ANALYSIS OF WIRE-EDM ON SUB-COOLED LOW-CARBON TOOL STEEL USING HYBRID MARCOS METHOD AND HONEY BADGER ALGORITHM

AISI P20 tool steel is commonly used for engineering of die holders, rails, plastic molds, wear strips, bolsters, shafts, and backers. When normally heated and sub-cooled, it experiences metallurgical modifications. Because the essential aspect of the “wire-electro discharge machine (WEDM)” is product finishing, this research examines the parametric responses when machining parent metal and sub-cooled metal (AISI P20). Thus, it is always necessary to choose a proper parametric arrangement for reaching maximum material removal rate (MRR), cutting speed with minimum surface roughness (SR), and kerf width. The effects of pulse on time, wire speed, discharge current, wire tension, and flushing pressure on individual machining reactions are also discussed in this study. An orthogonal array was created using Taguchi’s mixed experimental approach. The measurement alternatives and ranking according to compromise solution (MARCOS) method, the Honey Badger Algorithm, and the Taguchi-MARCOS method are engaged to obtain the important machining constraints and the optimal parametric settings for each response. When compared to the parent material, sub-cooled material has a greater cutting speed, SR, kerf breadth, and MRR. Here, cutting speed, MRR, and fitness were maximized along with minimization of SR and kerf width using the Honey Badger Algorithm as compared to both the MARCOS and Taguchi-MARCOS methods. According to ANOVA, for both parent and sub-cooled material, discharge current was the most significant and influential factor. The sub-cooled material’s machined surface contains smaller deposits and more spherical globules than the parent material, which has bigger melted deposits.

Modelling Microstructure in Casting of Steel via CALPHAD-Based ICME Approach

Integrated computational materials engineering (ICME) is emerging as an increasingly powerful approach to integrate computational materials science tools into a holistic system and address the multiscale modeling challenges in the processing of advanced steels. This work aims at incorporating macroscopic model (finite element-based thermal model) and microscopic model (CALPHAD-based microstructure model), building an industry-oriented computational tool (MICAST) for casting of steels. Two case studies were performed for solidification simulations of tool steel and stainless steel by using the CALPHAD approach (Thermo-Calc package and CALPHAD database). The predicted microsegregation results agree with the measured ones. In addition, two case studies were performed for continuous casting and ingot casting with selected steel grades, mold geometries and process conditions. The temperature distributions and histories in continuous casting and ingot casting process of steels were calculated using in-house finite-element code which is integrated in MICAST. The predicted temperature history from the casting process simulation was exported as input data for the DICTRA simulation of solidification. The resulting microsegregation by the DICTRA simulation can reflect the microstructure evolution in the real casting process. Current computational practice demonstrates that CALPHAD-based material models can be directly linked with casting process models to predict location-specific microstructures for smart material processing.

Experimental investigation and optimization of cutting parameters during dry turning process of copper alloy

Increasing the quality and productivity of machined components are the main issues of machining operations in metalworking industries. The copper alloys CuZr and CuCrZr generally find applications for current-carrying structural components, seam welder wheels, shafts, and bearings flash. The manufacturing of these components is still facing challenges in the form of machining process characteristics. One of the most common machining operations for removing material is turning that produces reasonably good surface finish quality, which is influenced by different factors (speed of cut, rate of feed, tool geometry, cutting fluid, cutting tool, etc.). This research has focused on experimental study and optimization of the cutting parameters viz. cutting speed, depth of cut, and feed, for best surface finish, material removal rate, tool tip temperature as well as surface morphology during dry turning of C15000 and C18150 copper alloy using High-Speed Steel (HSS) tool The plan and design of experiment has been performed through orthogonal Taguchi L9. array. The optimum cutting settings were discovered by using the Taguchi technique and using the performance index by applying a Grey Relational Grade (GRG). The best cutting parameters for both materials were a cutting speed 1200 rpm, feed rate 0.06 mm/rev, and depth of cut 1.25 mm. The optimum factors obtained from GRA for all responses (surface roughness, MRR, and tool temperature) at the best level of cutting parameters are the same for both materials. These cutting parameters values yielded the experimental result for each response like surface roughness, MRR, and tool tip temperature (2.5 µm,12,475 mm3/min, and 74 °C) for grade C15000 whereas (2.39 µm, 2590mm3/min and 68 °C) for grade C18150. The optimization of cutting parameters plays a vital role in the improvement of surface finish which minimizes mechanical failures caused by wear, corrosion, and thereby increasing the productivity of the products. This investigation is expected to help all researchers working in this area of applications.

Development of ceramic nanoparticles reinforced high Cr tool and die steels with high comprehensive performance

Simultaneously improved impact toughness and wear resistance of high Cr tool and die steels (HCS) enable them to be widely used in the lightweight field. In this study, TiC + TiB2/HCS steel was prepared by pre-dispersed ceramic nanoparticles combined with specific heat treatment. The effects of ceramic nanoparticles on the microstructures, mechanical properties and wear resistance of TiC + TiB2/HCS steel were investigated by comparing it with shield machine tool steel (H13 steel). The results demonstrated that the introduction of ceramic nanoparticles refined the microstructure of the TiC + TiB2/HCS steel and uniformed the distribution of the precipitates. For TiC + TiB2/HCS steel and H13 steel with the equivalent hardness values, the impact toughness and the wear resistance of TiC + TiB2/HCS steel were 67.3 % and 39.5 % higher than that of H13 steels, respectively. Moreover, when the wear resistance was comparable, the impact toughness of TiC + TiB2/HCS steel was 89.1 % higher than that of H13 steel. This study provides an innovative solution to prepare high-service performing service life tools and die steels to replace shield machine tool steels.

Functionally Graded Steels Obtained via Electron Beam Powder Bed Fusion

Electron-Beam Powder Bed Fusion (EB-PBF) is one of the most important metal additive manufacturing (AM) technologies. In EB-PBF, a focused electron beam is used to melt metal powders in a layer by layer approach. In this investigation two pre-alloyed steel-based powders, stainless steel 316L and V4E, a tool steel developed by Uddeholm, were used to manufacture functionally graded materials. In the proposed approach two powders are loaded into the feeding container, V4E powder on top of 316L one, preventing their mixing. Such type of feeding yields components with two distinct materials separated by a zone with gradual transition from 316L to V4E. Microstructure and local mechanical properties were evaluated in the manufactured samples. Optical Microscopy, Scanning Electron Microscopy and EDX on the polished cross-sections show a gradual microstructural and compositional transition from characteristic 316L at the bottom of the specimens to the tool steel towards the top. Nanoindentation experiments confirmed a consequent gradient in hardness and elastic modulus, which gradually increase towards the top surface of the samples. The achieved results provide great possibilities to tailor the composition, microstructure, mechanical properties, and wear resistance by combining different powders in the powder bed AM technology. Potential applications include the tooling industry, where hard and wear-resistant materials are demanded on the surface with tougher and more ductile materials in the core of the tool.

OPTIMIZATION EXPERIMENTAL STUDY OF MACHINING ENERGY CONSUMPTION OF ZIG-ZAG MILLING CUTTING PATH USING RSM.

Machining operations in CNC milling which remove the work material require power and energy to activate the machine components such as spindle motor, table and tool movement in order to withstand the high friction and load between tool and work material. Energy consumption during cutting operation is greatly influenced by the machining condition and parameters. This experimental research aims to investigate how energy responds to changes in the machining parameters such as depth of cut, spindle speed, and feed rate during face milling operation of CNC machine. The high-speed steel (HSS) tool with a 10mm diameter was used to face mill the 40mm x 40mm of Aluminum 6061. The design of experiment technique using Response Surface Methodology (RSM) is utilized to optimize the experimental work. Power usage and machining time were recorded for each machining process, which is then used to determine the machining energy consumption. The interaction between machining parameter and energy is comprehensively visualized using surface and contour plot. Additionally, the ANOVA analysis investigates the feed rate as the most influential parameter to the machining energy. Finally, the regression equation of machining energy is generated with reliability (R) value of 0.88 which can be used as an energy prediction model.