Machining Of Steel Research Articles

Effects of current intensities on material removal rate, electrode wear rate, and surface roughness of machining high carbon high chromium steel

AbstractThe electrical discharge machining is very successful and generally recognized for producing complicated shapes and small openings with exceptional precision. The objective of this study is to assess the impact of different electrical discharge machining parameters on the attributes of the machining process. The evaluation of the machining process was conducted based on the workpiece‘s material removal rate, the rate at which the electrodes wear, and the level of surface roughness. Simultaneously achieving a high material removal rate, low electrode wear rate, and high surface roughness is not possible with a specific combination of approaches due to their contradicting nature. Frequently, it is necessary to independently apply many measures instantaneously in order to assess their impact on various responses. This research investigates the machining of high carbon high chromium steel making use of electrical discharge machining with aluminum, copper, and graphite electrodes. The study focuses on the impact of different current intensities on the rate of material removal, electrode wear, and surface roughness. The experimental results demonstrate that the highest material removal rate (mmcubicmin−1) is achieved at a current density of 12 A when using a copper electrode (54.67), as opposed to aluminum electrode (22.91) and graphite electrode (29.43).

Sustainable machining of AISI4140 steel: a Taguchi-ANN perspective on eco-friendly metal cutting parameters

This work explores environmentally conscious machining practices for AISI4140 steel through Taguchi analysis. The study employs a design of experiments (DOE) approach, focusing on cutting speed, depth of cut, and coolant type as parameters. Taguchi’s L9 orthogonal array facilitates systematic experimentation, and the results are analyzed using MINITAB 17 software. Signal-to-noise ratios (SNR) are utilized to establish optimum operating conditions, evaluate individual parameter influences, and create linear regression models. The experiments reveal neem oil with graphene coolant as an eco-friendly solution, addressing health and environmental concerns. Main effects plots visually represent the impact of parameters on machining quality. Additionally, regression and artificial neural network (ANN) models are compared for surface roughness prediction, with ANN showing superior performance. The findings advocate for optimized cutting conditions, emphasizing material conservation, enhanced productivity, and eco-friendly practices in AISI4140 steel machining. This research contributes valuable insights for industries seeking sustainable machining solutions.

OPTIMISATION OF A NEEM OIL BASED MINIMUM QUANTITY LUBRICATING (MQL) SYSTEM PARAMETERS FOR THE ORTHOGONAL MACHINING OF MILD STEEL

Cutting tools experience early failure and dimensional variation due to the high temperature developed during machining. Conventional cutting fluid applications do not successfully remove heat because they do not reach the chip-tool contact. Operators on the work floor may experience the adverse side effects of cutting fluids, such as skin and respiratory issues. As a result, a different lubricating method is necessary for machining without harming the tool-workpiece, which would also be advantageous for health and the economy. This research aims to develop and evaluate the efficiency and optimization of minimal use of Neem seed oils as lubrication for the Taguchi L9 array-based design for machining of mild steel. The Taguchi optimization technique was used to examine the impact of the neem oil based Minimum quantity lubrication (MQL) system (with flow rate, air pressure and nozzle diameter as factors) on the workpiece temperature and chip thickness ratio at cutting speeds of 260 rpm and 470 rpm. The outcome demonstrated that optimal settings at 260 rpm were a flow rate of 50 ml/hr, air pressure of 1.5 bars, and nozzle diameter of 0.8 mm for workpiece temperature, and a flow rate of 100 ml/hr, air pressure of 1 bar, and nozzle diameter of 0.8 mm for chip thickness ratio. At 470 rpm, optimal settings for workpiece temperature were a flow rate of 50 ml/hr, air pressure of 1.5 bars, and nozzle diameter of 0.5 mm, while chip thickness ratio optimization indicated a flow rate of 100 ml/hr, air pressure of 1 bar, and nozzle diameter of 0.5 mm.

Comparative Analysis of CROYOGENIC and MQL Machining of EN-19 Steel

Comparative Analysis of CROYOGENIC and MQL Machining of EN-19 Steel

Performance improvement in electric discharge machining of hardox steel though modified circuits

Performance improvement in electric discharge machining of hardox steel though modified circuits

An Experimental Study in Laser-Assisted Machining of AerMet100 Steel.

To solve the problems of poor surface quality and low tool life in conventional machining (CM) of AerMet100 steel, an experimental study was conducted in laser-assisted machining (LAM) of AerMet100 steel. The effects of laser power, cutting speed, feed rate, and depth of cut on the surface roughness of AerMet100 steel were studied based on a single-factor experiment. The degree of influence of each factor on the surface roughness was evaluated by analyses of variance and range in the orthogonal experiment, and the combination of process parameters for the optimal surface roughness was obtained. The order of influence was as follows: laser power > cutting speed > depth of cut > feed rate; the optimal combination of process parameters was laser power 200 W, cutting speed 56.5 m/min, feed rate 0.018 mm/rev, and depth of cut 0.3 mm. Compared to CM, the surface morphology of the workpiece under the optimization of LAM was relatively smooth and flat, the surface roughness Ra was 0.402 μm, which was reduced by 62.11%, the flank wear was reduced from 208.69 μm to 52.17 μm, there were no tipping or notches, and the tool life was significantly improved. The study shows that the LAM of AerMet100 steel has obvious advantages in improving surface quality and reducing tool wear.

Internally cooled tools: An eco-friendly approach to wear reduction in AISI 304 stainless steel machining

Austenitic stainless steel 304 is widely used in various applications due to its mechanical strength, toughness, and, most importantly, its corrosion resistance. However, machining this material presents significant challenges, primarily due to its high tendency for work hardening and generation of elevated temperatures. In the cutting process, this temperature rise can result in premature tool wear, leading to a reduction in their lifespan. To address these issues, cutting fluids are typically applied. Although this component offers advantages, it also contributes to environmental pollution, health risks, and significant costs, including disposal.Therefore, this study introduces an Internally Cooled Tool (ICT) method aimed at reducing the heat generated during machining. In this study, an analysis of tool life and wear was conducted to evaluate the effectiveness of ICTs compared to conventional machining methods during the turning of austenitic stainless steel 304 using double-coated tools (AlCrN on TiAlN, PVD (Physical Vapor Deposition)). Additionally, the use of ICTs in combination with lubrication (hybrid machining Minimum Quantity Lubrication (MQL) + ICT) was also investigated. The study covered five machining atmospheres (ICT, ICT + MQL, dry, wet, MQL). Cutting conditions were kept constant, including cutting speed (vc = 400 m/min), feed rate (f = 0.1 mm/rev), and depth of cut (ap = 0.5 mm). Scanning electron microscopy (SEM) analyses were conducted to examine the wear mechanisms and types present in each condition, along with statistical tests such as analysis of variance and Tukey tests to validate the experiments. The results indicated that ICTs (ICT and ICT + MQL) showed a longer tool life compared to dry machining and MQL techniques, while the wet machining method did not demonstrate significance compared to this technique. The observed wear mechanisms included abrasion, adhesion, and diffusion, with abrasion being the predominant mechanism. In summary, it was found that the durability of the inserts was directly related to coating adhesion, as coating detachment quickly led to the end of the insert's lifespan.

Mechanical Properties, Structure and Machinability of the H13 Tool Steel Produced By Material Extrusion

Mechanical Properties, Structure and Machinability of the H13 Tool Steel Produced By Material Extrusion

Modeling of Wire EDM Using an Integrated Approach for Machining of AISI304 Stainless Steel

A non-traditional method of thermal machining called wire electrical discharge machining (WEDM) is utilized for the production of intricate and complex components, particularly those composed of difficult-to-machine materials. Stainless steel has gained widespread usage in various applications in contemporary industry owing to its exceptional properties. In this present investigation, a numerical 3D finite element modeling simulation was conducted using the ABAQUS software to analyze the Material Removal Rates (MRR) for both single and multi-discharge scenarios of AISI 304 stainless steel. The findings indicate a close correspondence between the MRR values predicted by the numerical modeling and those obtained experimentally corresponding to the optimal process parameters: I = 6 A, Ton = 45 s, and Toff = 5 s. Hence, this numerical approach offers the potential to forecast outcomes before actual machining operations.

A STUDY OF PROPERTIES OF AUSTENITIC STEEL IN THE INITIAL STATE

High-manganese steel is used in the rocket, space, and defense industries due to its low specific gravity, stable austenitic structure over a wide temperature range, and ability to strengthen under mechanical deformation. However, the wider application of this steel is hindered by such factors as: instability of mechanical properties in the initial state, tendency to thermal embrittlement and very poor machinability. Therefore, the work is aimed at solving the problems of eliminating the above-mentioned negative factors. Conducted studies of the effect of temperature-time parameters on the structure and properties of steel made it possible to establish the mechanism of thermal embrittlement of 9Г28Ю9МВБ steel. During slow cooling from hot deformation temperatures with speeds of the order of 0.03 º/s in steel, a large number of gray-blue coarse phase particles are released, which are located on the grain boundaries, which causes a sharp decrease in impact viscosity. It was established that in the temperature range of 500-800 ºС, the solid solution disintegrates with the release of particles of the strengthening K-phase - (Fe, Mn)3 AL, Cx. It was determined that the simultaneous decrease in hardness and impact strength in the temperature range of 750-950ºС provides a significant improvement in machinability. The lowest values of mechanical properties are achieved during aging at 700 ºС, the improvement of machinability in this case is maximal compared to exposure to other temperatures. So, for example, with an increase in the temperature of isothermal holding at 650ºС for 35 hours. machinability improves by almost 1.7 times, and for the same time at 700 ºС – by 2.4 times. When the holding temperature is increased to 950ºС for 35 hours. the machinability of steel increases only 1.6 times, which is due to the less intense decomposition of the saturated solid solution. Significant anisotropy of mechanical properties is formed as a result of the development of liquid chemical heterogeneity and its imitation during further thermomechanical processing. The value of the coefficient of anisotropy in sample bars of different grades of initial steel reaches values from 1.5 for a bar with a cross section of 105x105 mm to 3.9 units for a bar with a diameter of 120 mm. The study of the influence of the annealing temperature on the homogeneity of austenitic steel made it possible to develop a mode of heat treatment of austenitic steel 9Г28Ю9МВБ, which consists of heating to 1250°С, holding for 2 hours. at this temperature and subsequent cooling in water, in order to fix a homogeneous supersaturated solid solution. After such heat treatment, the striated microchemical heterogeneity is significantly reduced, the anisotropy coefficient does not exceed 1.1 units for all types of steel assortment.

Effect of gadolinium on the machinability of an Al-killed high sulfur steel

The effect of various gadolinium contents on the number density and morphology of sulfide in Al-killed high-sulfur steel was investigated. Meanwhile, the effect of characterization of sulfide inclusions, i.e., number density and morphology on the cutting performance of steel also were studied. The evolution process of sulfide inclusions with the increasing T.Gd content from 0 ppm to 198 ppm in steel samples could be described as follows: MnS → (Gd-O-S)-MnS→(Gd-S)-MnS →Gd-S. As the gadolinium content in the steel increased, sulfide inclusions with an aspect ratio of < 3 increased from 26.1 % to 99.7 % and the number density of sulfides decreased from 438 #/mm2 to 80.4 #/mm2. Spherical sulfides could form micro-holes during cutting, facilitating the chip-breaking process, whereas long-strip MnS tended to self-break during cutting. The higher the proportion of C-type chips in the cutting process, the better the cutting performance of the material. Therefore, spherical sulfides exhibited superior modification effects on surface finishes compared to long-strip sulfides. In low-speed cutting, sulfide morphology predominantly affected surface roughness, while in high-speed cutting, the number density of sulfides became the dominant factor. The addition of gadolinium can effectively decrease the surface roughness of the material at various cutting parameters. Moreover, the Gd-O film can be formed on the tool surface was observed after the addition of gadolinium in the steel, which can increase the lubrication during the cutting process and reduce the tool surface wear.

Influence of the Machining Process on the Wear Properties of Self-Mated Structural Steel in Dry Sliding Conditions

This work investigates the tribological behavior of a machined S355JR structural steel in dry sliding conditions for the development of an innovative seismic dissipation system. Flat-ended pins and disks were made of the same structural steel to simulate the conformal contact of different device parts. Pins were machined by turning, while disks were milled and turned to obtain a nominal average surface Ra roughness ranging from 0.8 µm to 6.3 µm. The influence of the surface roughness on the coefficient of friction (COF), specific wear rate (SWR), and time to steady-state (TSS) was investigated. Tribological tests were conducted reciprocating motion in dry sliding conditions to simulate the operating conditions of the device, with 1 Hz and 2 Hz reciprocating frequencies and an applied normal load of 50 N. The Rsk and Rku roughness parameters helped to better understand the tribological response of milled and turned disks, having an influence on the TSS and SWR.

Magnetic and acoustic sensors in the age of digitalization for industrial production

The challenges of digitalization are giving rise to new generations of measurement technology. This does not necessarily involve the use of new physical principles; rather, the importance of handling and generating valuable data has increased. We present a new measuring system that samples and digitizes analogue signals at 50 MHz with 24-bit conversion. Every 43 µs, a Fourier step is generated for 1,024 data points via an FPGA-based measurement card. The resulting spectral data diagram can then be electronically filtered to improve the signal-to-noise ratio. With this procedure, further possibilities have been created to improve data analysis and data handling, one of which is a parametric pattern recognition, which transfers selectable signals to a library based on the spectral data diagram and searches for them in future data using a similarity algorithm. The use of Python is another building block. With Python, machine learning methods can be transferred from training directly to the measurement system and can run there directly using the extensive library standards. Sensor-fusion is a module that allows analog data to be analyzed via the measurement card, but at the same time also links digital data with analog data by connecting DAQ modules from a third source as virtual ports and transmitting values to shared databases. This article shows the application of the described measurement concept using magneto-inductive sensors and piezoelectric sensors. Magnetic sensors react sensitively to material changes and can reliably determine mechanical parameters such as hardness, residual stresses and grain size. The mentioned software functions enable non-contact measurement of ferromagnetic materials at high throughput speeds. So far limited to laboratory applications, magnetic sensors can also be used safely in harsh industrial conditions. Applications include rapid differentiation of heat treatment conditions, detection of grinding burn and hardness measurements. Acoustic sensors are used in areas that are difficult to access or whose environmental conditions make the use of optical systems in particular difficult. The sensors can mainly detect cracks, frictional behaviour and wear quantities. Applications are in particular straightening processes of hardened steel components, wire drawing, welding, deep drawing and machining. In general, this method can also be used to monitor other sensors and thus raise them to a new level of evaluation technology and data analysis.

Optimization of Cutting Parameters for Energy Efficiency in Wire Electrical Discharge Machining of AISI D2 Steel

Optimization of Cutting Parameters for Energy Efficiency in Wire Electrical Discharge Machining of AISI D2 Steel

Improvements in Machinability, Microhardness, and Impact Toughness of AISI O1 and AISI D2 Alloy Steels by Controlling the Grain Size During Heat Treatment

Improvements in Machinability, Microhardness, and Impact Toughness of AISI O1 and AISI D2 Alloy Steels by Controlling the Grain Size During Heat Treatment

Investigation of the effects of machining parameters on cutting conditions during orthogonal turning of austenite stainless steel

Abstract The 1.4306 austenite stainless steel has been prominently utilized as a material in the automotive and aerospace industry. Considerable interest has been garnered in the machinability of stainless steel owing to its high strength and poor thermal conductivity. The aim of this study is to ascertain the influential cutting parameters, specifically the cutting speed and feed rate, on cut-ting forces, cutting temperature, and chip evaluation. Thus, austenite stainless steel was subjected to free-cutting using a carbide recessing tool under dry conditions. The principle of measuring cutting temperature, a complex procedure due to varying thermal homogeneity, was elucidated. For the turning experiments in question, the standard Taguchi orthogonal array L9 (32), featuring two factors and three levels, was employed. The experimental results were analyzed using MiniTab 17 software. The findings reveal a substantial effect of feed rate on cutting force, cutting temperature, and chip evaluation. The highest cutting force and cutting temperature were observed at a feed rate of 0.15 mm/rev. Conversely, the cutting force was minimized at a cutting speed of 100 m/min, indicating potential for increasing the cutting speed. The augmentation of feed rate led to chip compression and discoloration, attributed to elevated cutting force and a larger chip cross-section that efficiently dissipates heat from the cutting zone.

Multiobjective Optimization of Hard Turning on OHNS Steel Using Desirability and TOPSIS Approaches

Machining hard materials with 45–48 HRC is difficult in turning operation because of the improvident cutting parameter selections for the operation. The OHNS (AISI/SAE-01–48HRC) steel is mainly preferred for the production of shafts, gears, cams, and press tools. The OHNS material was turned at a dry state using VP-coated carbide inserts. The seventeen experimental trials were designed by central composite design (CCD) with different levels of cutting parameters, like feed rate, cutting speed, and depth of cut. Design Expert-11 software desirability approach and TOPSIS (Technique for Order Preference by Simulating the Ideal Solution) were used to analyse the experimental results to obtain a single optimal solution that defines better results on metal removal rate (MRR) and surface finish (Ra). RSM solution with 81.3% desirability, the cutting speed of 60 m/min, feed rate of 0.08 mm/rev, and depth of cut 1 mm as the optimal cutting parameters; similarly, TOPSIS algorithm calculation identifies the cutting parameter combinations, such as 40 m/min cutting speed, 0.09 mm/rev feed rate, and 1 mm depth cut to enrich the quality of the machined steel; however, the desirability approach cutting parameter setting is better for the surface finish achievement, while TOPSIS solution is better to obtain significant MRR. The confirmation test results validated for the predicted values of both approaches; as such, the experimental results were maintained better convenience than the predicted one. For the optimum cutting parameter combinations, an MRR of 22.032 gm/min and surface roughness of 0.781 μm were obtained at 60 m/min cutting speed, 0.08 mm/rev feed rate, and 1 mm depth of cut.

The Experimental Investigation of the Machinability of Armor Steels

In recent years, the use of materials with ultra-high hardness such as Millux Protection 600T has become widespread in industry. However, the effect of different parameters used in the machining process of such steels, especially factors such as feed rate, cutting speed, depth of cut, and radial depth of cut, on the surface roughness of the final product is still not fully understood. In this context, a study was conducted to evaluate the effects of the mentioned armor steel on surface roughness. Using the Taguchi optimization method, the interaction between processing parameters at specified levels was examined, and attempts were made to determine the optimum values. Within the scope of the study, nine different experiments were conducted using Taguchi's L9 orthogonal array, and the surface roughness data obtained from each experiment were recorded. According to the analysis results, it was determined that the feed rate is the most significant parameter in the milling process, followed by radial depth of cut, depth of cut, and cutting speed, respectively. To achieve optimal results, it is recommended that the feed rate be set to level 1, cutting speed to level 2, depth of cut to level 1, and radial depth of cut to level 3. These findings could provide important guidance in the machining of such steels.

Innovative technology for increasing of tool performance when turning difficult-to-cut corrosion-resistant steels

An innovative technology is developed and implemented to increase the performance of turning tools during external machining of corrosion-resistant steels using new coatings for the ВК8 alloy. The performance of the tool is determined by the service life of replaceable standard cutting inserts. The allowable wear of 0,5 mm is accepted on the rear edge. The durability period is increased by up to 3 times without reducing of processing productivity and the quality of the treated surface. Keywords:coating, ВК8 alloy, turning, corrosion-resistant steel, increasing the service life of cutters boris@knastu.ru, avkosm@knastu.ru

Optimization of Surface Roughness and Cutting Temperature in Turning of 1.4534 Stainless Steel under Sustainable Conditions

1.4534 stainless steel, which is produced especially for aerospace applications, is frequently preferred in aircraft landing sets under high load and in highly corrosive environments. In addition to its superior properties, its machinability rate is low compared to other stainless steels. Moreover, improving 1.4534 stainless steel's machining performance is crucial since its formability problems. In this study, 1.4534 stainless steel was tested in a series of experiments under sustainable conditions (hBN, CO2, and hBN+CO2). Taguchi techniques were used in the experimental design to save cost and time. Three cooling levels (hBN, CO2, and hBN+CO2), three cutting speeds (140, 200, and 260 m/min), three feed rates (0.12, 0.16, and 0.20 mm/rev), and a constant cutting speed (0.8 mm) were used in the current study. Analysis of variance (ANOVA) was performed in the current study to determine the extent of the components' effects since cutting temperature and surface roughness were chosen as the performance standard. According to the test results obtained; hBN+CO2 condition showed the best performance for surface roughness and cutting temperature.