High Carbon High Chromium Research Articles

Laser Directed Energy Deposition of High-Carbon High-Chromium D2 Tool Steel Structures: Processing, Heat Treatment and Material Behavior

Laser Directed Energy Deposition of High-Carbon High-Chromium D2 Tool Steel Structures: Processing, Heat Treatment and Material Behavior

Effect of Ultrasonic Nanocrystal Surface Modification on Wear Properties of High-Carbon High-Chromium Steel

Effect of Ultrasonic Nanocrystal Surface Modification on Wear Properties of High-Carbon High-Chromium Steel

Effect of heat treatment on hardness and wear resistance of high carbon-high chromium steel (FMU-11)

In the present study, microstructure, hardness, and abrasion resistance of a heat-treated high carbon-high chromium steel (FMU-11) used in the cement mills were investigated. To investigate the best heat-treating cycle for the FMU-11 steel, three sets of samples were heat treated. The first set was tempered two times, the second set was re-hardened, and the third set was cryogenically heat treated. These samples were then compared with the conventionally heat-treated samples. The samples' microstructure was studied using an optical microscope, where traditional black and white etching, as well as color etching, were used. Scanning electron microscopy (SEM) was applied for higher magnification studies and in-depth analysis of the chemical composition. The mechanical properties were investigated by measuring the hardness and the wear resistance for the samples heat-treated in different cycles. The results showed that the cryogenic treatment and double-tempered samples had the highest hardness and wear resistance. In addition, the results showed that the re-hardening operation caused the carbides to be finely separated and evenly distributed in the steel matrix. The wear test results illustrated that the wear mechanism could be the delamination wear and the abrasive wear combined.

Evolution of the Fretting Wear Damage of a Complex Phase Compound Layer for a Nitrided High-Carbon High-Chromium Steel

In this paper, the X210CrW12 steel was subjected to gas nitriding to obtain a complex phase compound layer with limited porosity. The nitrided layer was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The fretting wear behavior and the evolution of fretting wear damage of the compound layer were studied, and the worn surfaces were characterized by SEM/EDS and 3D optical profilometry. The results indicated that the compound layer showed superior fretting wear resistance and sufficient load-carrying capacity in the low loading case of 35 N, but the fracture of coarse nitrides (transformed primary carbides) was obviously detrimental to wear resistance. For the high loading case of 70 N, the low toughness of the compound layer led to the occurrence of brittle cracks, and the decrease in the thickness of the compound layer due to wear resulted in the cracking and spalling of the compound layer.

Predictive analysis of surface roughness in argon-assisted EDM using semiempirical and ANN techniques

This experimentation explores the utilization of argon-assisted electrical discharge machining (AAEDM) of high-carbon high-chromium die steel. High-pressure argon gas in conventional EDM was utilized to assess the surface roughness (SR). Analysis of variance was connected to decide the critical parameters influencing SR. In this study, a mathematical model has been instigated to get to know SR by using Buckingham pi-theorem while applying the AAEDM process. The fit summary confirmed that the quadratic model is statistically appropriate, and the lack-of-fit is insignificant. Root-mean-square error and absolute standard deviation, obtained through response surface method, were also used for developing the model and for its predicting abilities through ANN. The experiment and anticipated estimates of SR during the process, obtained by dimensional analysis and ANN, were found to be in accord with each other. However, the ANN technique proved to be more fitting to the response as compared to the dimensional analysis.

Selection of WEDM parameters to measure the performance and productivity of die steel grade D3 using GRA and fuzzy logic system

PurposeThe purpose of this paper is to examine the performance parameters of WEDM to improve the productivity and material removal rate (MRR) with a high surface finish of high chromium-high carbon dies steel.Design/methodology/approachThe experiments were performed on AGIE CUT 220 CNC WEDM. High chromium-high carbon dies steel (D3) was used in the form of a rectangular plate. The workpiece and the brass wire having diameter ɸ 0.25 mm had linked up with +ve and –ve polarity in the DC power source, respectively. De-ionized water having a conductivity level of 0.6 µs/cm was used as the dielectric medium. The dielectric fluid was flushed from the top and bottom nozzles and material was submerged in the dielectric.FindingsThe WEDM process parameters for D3 die steel had optimized by using Grey relational analysis method couples with Taguchi method. The optimum solution has been calculated for MRR, cutting speed (Cs), machining time and surface roughness (SR) (Ra value). A fuzzy logic model using Matlab was developed for the prediction of performance parameters, namely MRR, cutting speed (Cs), machining time (M/c time) and SR with respect to changes in input parameters.Research limitations/implicationsThe fuzzy model shows the 96.19 percent accuracy between the experimental values and the predicted values.Practical implicationsThe optimized parameters by multi-parametric optimization method showed considerable improvement in the process and will facilitate the WEDM, tool and die industries, defense and aerospace industries to improve the productivity with the higher surface finish.Originality/valueThis manuscript represents valid work and the authors have no conflict of interests. The attained optimum outcomes had also been examined through a real experiment and established to be satisfactory.

Hard turning of high-carbon high chromium tool steel using CBN tools under different lubricating/cooling conditions

The application of environment-friendly cutting fluid in machining processes can strongly influence the wear on the cutting tools and the surface finish on workpiece materials. This is only possible, when the cutting fluid provides better penetration into the cutting zone, thereby providing a better cooling and lubricating effect. Therefore, this study aims to show the effect of various cutting fluid cooling conditions and machining parameters on tool flank wear (VB) and surface roughness (Ra) of the work piece while turning AISID2 steel with coated CBN tools. By adopting RSM technique with FCCD and using analysis of variance, the effect of cutting parameters on desired outputs was explored. The results showed that machining time was the most dominant parameter influencing both tool wear and surface roughness. Moreover, cutting fluid conditions also showed considerable contribution towards decreasing tool wear rate and increasing surface finish. In addition, the cutting tools were examined under scanning electron microscope (SEM) together with EDS. It was observed that abrasion along with BUE formation were the most dominant wear mechanism modes at low cutting speeds. However, at higher cutting speed and feed combinations, abrasions followed by diffusion and adhesion were the dominant form of wear mechanisms. Suppression of BUE was observed at higher cutting speeds of CBN tools. Finally, desirability function approach (DFA) was used to find out the optimal cutting parameters for minimum tool wear with the maximum surface finish .

Carbide Fragmentation and Dissolution in a High-Carbon High-Chromium Steel Using Hot Rolling Process: Microstructure Evolution, Wear, High-Temperature Oxidation, and Chloride-Induced Corrosion Properties

A series of hot rolling processes with different reduction percentages (10%, 30%, and 50%) were applied to a high-carbon high-chromium tool steel (2HCTS). Microstructural evolutions, wear behavior, high-temperature oxidation, and aqueous corrosion properties were investigated. The results revealed the breakage and dissolution of primary carbides and a uniform carbide distribution after the hot rolling process. It was proposed that the presence of higher amounts of dissolved chromium in the hot rolled samples leads to the formation of Cr-rich oxides with more protection and less porosity at high temperatures, as well as an improved corrosion behavior in 3.5 wt% NaCl solution. This improvement in the corrosion behavior is not at the expense of the degradation of wear resistance. Probable mechanisms for carbides dissolution are also discussed.

Effect Of Machining Parameters On Cutting Tool Temperature And Tool Life While Turning EN24 And Hchcr Grade Alloy Steel

Converting raw materials in to the finished product is the primary objective of machining, in order to obtain desired quality in terms of surface texture and dimension. While machining alloy steels of grade EN24 & High Carbon High Chromium (HCHCr), the cutting tools are subjected to higher wear due to the presence of alloying elements such as chromium, vanadium and Molybdenum which leads to increase of cutting tool temperature and hence reduction in tool life. The tool life and cutting tool temperature study were carried out at varied cutting speeds, feeds and constant depth of cut. The experiments carried out following ISO3685 standards. The experimental results revealed that the tool life found higher during continuous turning of EN24 and HCHCr alloy steels with M15 grade multilayer coated carbide insert when compared to that of M20 grade multilayer coated carbide insert by around 35%.

FRICTION STIR WELDING OF NYLON -6: EFFECT OF PROCESS PARAMETERS ON MECHANICAL AND MICROSTRUCTURAL PROPERTIES

Friction stir welding (FSW) is solid state joining process with more advantages than that of fusion welding. Nylon -6 is one of the engineering plastics used widely in various industrial applications. The main aim of this research work is to investigate the effect of tool rotational speed and tool traversing speed on the mechanical and microstructural properties of the nylon-6 butt welded joints made by FSW. The FSW process was performed in a computer numerically controlled (CNC) vertical milling machine using a cylindrical tool with threaded pin made of heat treated high carbon high chromium (HCHCr) steel. The tensile testing and microscopic examinations were carried out to study the mechanical and microstructural properties of the welded joints. In visual inspection, it is observed that the excessive flashes are observed on either sides of the weld line in all cases. From the results, it is observed that the maximum tensile properties are achieved in a joint made which is approximately 18% and 26% of the parent material’s ultimate tensile strength (UTS) and yield strength (YS) respectively with the tool rotational speed 1200 rpm and the tool traversing speed of 30 mm/min within the experimented process parameters. Overall, the tensile properties of the welded joints made using the experimented process parameters are very much lower than the parent material.

Investigations on the effects of Nano-fluid in ECM of die steel

Formation of spikes in the electrochemically machined workpiece prevents to achieve the better performance of ElectroChemical Machining (ECM). Hence, this research work attempts to investigate the effects of Nano-fluid i.e. Nano Copper particles suspended NaCl electrolyte on the ECM of High carbon high chromium (HCHCr) die steel with a hardness of 63HRc. The influencing parameters are voltage, tool feed rate and electrolyte discharge rate with mixing levels. Seventy-two experiments have been conducted using Nano-fluid and plain NaCl electrolyte based on design of the experiment. The Nano Copper particles in the electrolyte break the gas layer at the inter electrode gap resulting in better MRR and surface roughness due to improved current density across the gap. A maximum MRR of 458.869mm3/min and a minimum surface roughness of 1.39μm Ra are obtained using Nano-fluid. The developed ANOVA models prove the significances of influencing factors in obtaining the better performance of ECM.

Experimental Investigation on the Effects of Nano Fluid in ECM of High Carbon High Chromium Die Tool Steel

The formation of spikes in Electrochemical Machining (ECM) of High carbon high chromium die steel prevent to achieve the better Material removal rate (MRR) and surface finish using NaCl aqua electrolyte. Hence, this research work attempts to investigate the effects of Nano fluid i.e., Copper nano particles suspended Sodium Chloride (NaCl) aqua electrolyte on the Electrochemical Machining (ECM) of High carbon high chromium (HCHCr) die steel. The electrochemically machined work piece is one of the tremendously utilized materials in most of automotive industries despite of its poor machinability. The objective of this research is to minimize the formation of spikes using nano particle suspended electrolyte results higher MRR and lower surface finish. The selected influencing parameters are applied voltage, electrolyte discharge rate and tool feed rate with different levels. Seventy two experiments are conducted on HCHCr die steel using nano fluid. The results reveal that nano fluid significantly improves the MRR and surface finish than that of plain NaCl aqua electrolyte by 15.44% higher MRR and 41.49% lower surface roughness.

Boriding of high carbon high chromium cold work tool steel

High-carbon high-chromium cold work tool steels are widely used for blanking and cold forming of punches and dies. It is always advantageous to obtain an increased wear resistant surface to improve life and performance of these steels. In this connection boriding of a high-carbon high-chromium cold work die steel, D3, was conducted in a mixture of 30% B4C, 70% borax at 950 °C for two, four and six hours. Case depth of the borided layer obtained was between 40 to 80 μm. After boriding, the surface hardness achieved was between 1430 to 1544 HV depending upon the process time. X-ray diffraction studies confirmed the formation of a duplex compound layer consisting of FeB and Fe2B. It is generally considered that FeB is undesirable because of its inherent brittleness. Post boriding treatment (homogenization) transformed the compound layer into single-phase layer of Fe2B, while surface hardness decreased to 1345-1430 HV. Pin-on-disc wer test showed that wear resistance of the borided samples was superior as compared to non-borided material and increased with boriding time.

Comparing microstructure and mechanical properties of AISI D2 steel after bright hardening and oil quenching

D2 is a high carbon-high chromium cold work tool steel. The main problems of hardening treatment of this steel include risk of crack distortion and formation because of thermal shocks induced by oil quenching (conventional hardening treatment for D2 steel). For this purpose, in this study, the possibility of improving microstructure and mechanical properties of AISI D2 steel and decreasing the risk of cracking by bright hardening in comparison with oil quenching was investigated. The quenchant used in bright hardening included 60% of KOH and 40% of NaOH. The bright-hardened samples showed no cracks during their heat treatment, which was in contrast to oil-quenched ones. Moreover, microstructural examinations of the samples revealed that, compared with oil-quenched samples, quenching in hot alkaline salt bath resulted in finer and more uniform distribution of carbides and also lower amount of retained austenite in the matrix. Different microstructures caused the samples to possess different mechanical properties; e.g. bright-hardened samples possessed higher impact toughness (3.7J) and tensile strength (1764MPa) as well as higher level of hardness (792HV) than those of oil-quenched samples, which were 3.2J, 1608MPa and 710HV, respectively.

Optimizations of Edm Process Parameters for Surface Roughness Machining Die Steel Using Copper Tungsten Electrode by Adopting Taguchi Array Design

In this paper, machining of hard material High Carbon High Chromium (HCHCr) die steel using Electrical Discharge Machining (EDM) with a Copper-tungsten electrode by using Tagughi methodology has been reported. The Taguchi method is used to formulate the experiment format, to analyze the effect of each control factors on machining characteristics, and predicts the optimal EDM control factor such as Servo voltage, pulse current, pulse duration and interval time. It is found that these control factors have a significant influence on machining characteristics such as material removal rate, electrode wear and Surface roughness. In order to see the impact of control factors on quality characteristic, number of experiments were conducted and. results were analyzed by Taguchi methodology and analysis of variance (standard analysis). The effect of control factors were examined for obtaining optimum surface roughness. The analysis of Taguchi method reveals that, peak current, servo voltage and pulse duration have significantly affected the surface roughness.

OPTIMIZATION OF CNC WEDM PROCESS PARAMETERS OF HIGH CHROMIUM HIGH CARBON (HCHC) DIE STEEL USING TAGUCHI METHODOLOGY

This paper presents an investigation on the effect and optimization of machining process parameters on the Material removal rate (MRR) and surface roughness (SR) in CNC wire electrical discharge machining (WEDM) operations. The cutting of High Chromium High Carbon (HCHC) die steel work piece using CNC WEDM by using Taguchi methodology has been reported. Many experiments were conducted to consider the effect of Current, Voltage, Wire speed and Wire tension on the MRR and SR response. An L9 (3*4) Taguchi standard orthogonal array (OA) is chosen for design of experiments and the main influencing factor are determined for each given machining criteria by using Analysis of variance (ANOVA). We found out the optimal parameter setting for MRR and SR. The analysis of the Taguchi methodology reveals that. In general the Current significantly affect the MRR and SR. Experimental observed values are provided to verify this methodology.

Study of Material Transfer Mechanism in Die Steels Using Powder Mixed Electric Discharge Machining

The present article investigates the effect of process parameters and mechanism of material deposition in powder mixed electric discharge machining (PMEDM) on surface properties of EN31, H11, and High Carbon High Chromium (HCHCr) die steel materials. Current, powder, and interaction between workpiece and electrode affected the microhardness significantly. Copper electrode was found best for EN31 and H11 die steel, whereas tungsten-copper electrode was better suited for HCHCr steel to achieve higher microhardness. Graphite powder was found to be more suitable compared to aluminum in improving the microhardness of all three materials. Selected samples were analyzed for X-ray diffraction (XRD) followed by microstructure analysis using a scanning electron microscope (SEM). The results showed significant material transfer from the electrode as well as powder, either in free form and/or in compound form. For maximizing the microhardness of the machined surface, optimum parametric settings were identified for the three materials.

Optimal parameter settings for rough and finish machining of die steels in powder-mixed EDM

The present study was undertaken to identify the appropriate parameter settings for rough and finish machined surface for EN31, H11, and high carbon high chromium (HCHCr) die steel materials in a powder-mixed electric discharge machining process. The effect of seven different process variables along with some of their interactions was evaluated using a dummy-treated experimental design and analysis of variance. Material removal rate (MRR), tool wear rate, and surface finish were measured after each trial and analyzed. The parameter settings for rough and finished machining operations were obtained. EN31 exhibited maximum MRR as compared to the other two materials at similar process settings. Copper (Cu) electrode with aluminum suspended in the dielectric maximized the MRR. Suspending powder in the dielectric resulted in surface modification. Graphite powder showed a lower MRR but improved the surface finish. HCHCr require higher current and pulse on settings for initiating a machining cut and works best in combination with tungsten–Cu electrode and graphite powder for improved finish. The MRR for H11 is lower than EN31 but significantly higher than HCHCr under same process conditions.

Optimization of powder mixed electric discharge machining using dummy treated experimental design with analytic hierarchy process

The analytic hierarchy process (AHP) is widely used for the optimization of multiple responses from an experimental study. In the present study, a method to obtain more reliable global weight of different alternatives has been described for a powder-mixed electric discharge machining (EDM) process. Seven different process parameters were tested to study their effect on material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR) using a specially designed Taguchi orthogonal array that could accommodate factors with varying number of levels. A three-level array L27 was modified to include two-level factors using dummy treatment. The process conditions that affected the three responses were identified and optimized together using AHP for high carbon high chromium (HCHCr), EN31 and hot die steel (HDS) workpiece material. Addition of powder in the dielectric improved the MRR as the electrical conductivity of powder reduces the dielectric insulating strength. Current, powder, and electrode material significantly affected the TWR. Kerosene as dielectric was observed to be a superior alternative than EDM oil. Graphite electrode worked best for HCHCr and EN31 and W–Cu electrode worked best for HDS as they globally optimize the three output variables. Also, Cu powder suspended in the dielectric resulted in an optimal solution for HCHCr and HDS and tungsten powder was seen to be a better choice for EN31 to globally optimize the responses. To overcome problems of poor finish at high current setting in EDM, the dielectric should be mixed with powder.

Surface Modification of High Carbon High Chromium, EN31 and Hot Die Steel Using Powder Mixed EDM Process

This paper investigates the effect of electric discharge machining (EDM) process parameters and powder mixed in dielectric on surface properties of three die steel work materials; namely High Carbon High Chromium (HCHCr), EN 31 and Hot Die Steel (HDS). The mechanism of material deposition from the suspended powder and/or tool electrode is reported. Current emerged as the most significant factor affecting the microhardness along with powder mixed in the dielectric and electrode material. Amongst the two electrode materials, copper-tungsten along with tungsten powder had the best microhardness. Selected samples were analyzed for X-ray Diffraction (XRD) followed by microstructure analysis using a Scanning Electron Microscope (SEM). The results showed significant material transfer from the electrode as well as powder either in free form or in compound form. It was concluded that surface modification of die steels can be done by incorporating simple modifications in the EDM set-up resulting in higher microhardness and superior wear resistance of the machined surface.