Quenching Process Parameters Research Articles

Numerical Simulation and Experimental Research on the Quenching Process of 1045 Steel Based on Thermo–Fluid–Solid Coupling Model

In the numerical simulation research on quenching, the heat transfer coefficient is an important input parameter. However, owing to its complexity and various influencing factors, the measured results are not universal and will significantly increase the simulation complexity and error. This article proposes a new numerical simulation method for quenching processes by extending the simulation domain and introducing the coupled heat exchange between the liquid quenching medium and workpiece, replacing the role of the heat transfer coefficient in the numerical simulation. The method is validated through experimental studies on 1045 steel rod quenched in water, with the maximum relative errors of the simulation results compared to the experimental results being 3.6%, 9%, and 5.1% for hardness, cooling curve, and residual stress, respectively. Furthermore, the article investigates the effect of different flow parameters of quenching media on the quenching effect. Under the studied conditions, the 1045 steel rod has the lowest risk of cracking and the highest hardness value when quenched in water at 50 °C. The proposed method improves the universality and convenience of numerical simulation for the quenching process and can be used to guide the formulation of quenching process parameters when the heat transfer coefficient is unknown.

Optimization of laser irradiation process parameters for 40Cr steel based on back propagation neural network and genetic algorithm

40Cr is a significant material in the manufacturing of gears. However, this process is plagued by uneven distribution of quenching layers and excessive residual stress, leading to a decline in the precision of the workpiece, deformation, and cracking. Relying solely on the trial-and-error method in experiments is inadequate for effectively revealing the evolution mechanism of the laser quenching process. This approach is detrimental to improving research and development efficiency. In this study, a multi-field coupled numerical model for the multi-track overlapping laser quenching of the 40Cr gear steel is established. This model quantitatively reveals the coupling evolution laws of the temperature field, stress field, and phase transformation field during the laser quenching. The focus is on calculating the size of the tempering zone under different overlapping rates and conducting correlation analysis between parameters. Based on the artificial neural networks and genetic algorithms, the width and depth of the tempering zone are selected as target values for parameter optimization. The aim is to find the nonlinear relationship between the laser power, spot diameter, scanning speed, laser overlapping rate, and the size of the tempering zone, which can accurately predict the size of the tempering zone. The material microstructure of 40Cr gear steel was characterized by the scanning electron microscope, microhardness tester and friction and wear tester. The results show that the training error and testing error of the output parameters in genetic algorithm optimized back propagation network can accurately predict the size of the tempering zone. It is found that the higher the lap rate, the more uniform the hardness of the phase transformation hardening layer surface, and the tempering softening zone becomes larger. The parts surface is easy to produce defects, which can provide a theoretical basis for optimizing the laser quenching process parameters.

Numerical Modeling for the Prediction of Microstructure and Mechanical Properties of Quenched Automotive Steel Pieces.

In this work, we present an efficient numerical tool for the prediction of the final microstructure, mechanical properties, and distortions of automotive steel spindles subjected to quenching processes by immersion in liquid tanks. The complete model, which consists of a two-way coupled thermal-metallurgical model and a subsequent (one-way coupled) mechanical model, was numerically implemented using finite element methods. The thermal model includes a novel generalized solid-to-liquid heat transfer model that depends explicitly on the piece's characteristic size, the physical properties of the quenching fluid, and quenching process parameters. The resulting numerical tool is experimentally validated by comparison with the final microstructure and hardness distributions obtained on automotive spindles subjected to two different industrial quenching processes: (i) a batch-type quenching process with a soaking air-furnace stage prior to the quenching, and (ii) a direct quenching process where the pieces are submerged directly in the liquid just after forging. The complete model retains accurately, at a reduced computational cost, the main features of the different heat transfer mechanisms, with deviations in the temperature evolution and final microstructure lower than 7.5% and 12%, respectively. In the framework of the increasing relevance of digital twins in industry, this model is a useful tool not only to predict the final properties of quenched industrial pieces but also to redesign and optimize the quenching process.

Numerical simulation and correlation research of multi-track overlapping laser quenching process for 40Cr steel

Laser quenching has a short process cycle and high production efficiency, and it plays an important role in automobile, ship, machinery manufacturing, and other fields. The surface hardness of 40Cr steel laser quenching parts is uneven by unreasonable set on the quenching overlap zone. This will affect the microstructure of the quenched layer, resulting in cracking, corrosion during service, and other hazards that ultimately reduce reliability. Numerical simulations provide an effective way to quantitatively reveal the transient evolution of the multi-field coupling between temperature field, stress field, and phase transition field in quenching, which directly determines the extent of the overlap zone and quenching properties. The quenched phase transition layer profile is predicted to effectively determine the extent of the secondary tempering softening zone and solve the bottleneck problem of uneven surface hardness in quenching. The innovation of this paper is to establish a multi-field coupled numerical model of the 40Cr steel multi-track laser quenching process. The transient quenching temperature, phase transition hardening, and stress distribution were numerically calculated, and the size of the tempering zone under different overlapping rates was evaluated, revealing the internal coupling mechanism and correlation between multi-fields during the laser quenching. The quenching temperature, microstructure, and hardness distribution of 40Cr steel were tested by an infrared thermometer, Axio Vert A1 Zeiss microscope, Thermo ScientificTM Apreo scanning electron microscope, and Q10M microhardness tester, which verified the effectiveness of numerical simulation. The research can provide an important theoretical basis for optimizing quenching process parameters in production.

Simulation and experimental study of GGG70L laser quenching

GGG70L is a kind of cold-working die steel widely used in large automobile cover parts die. In order to ensure the life of the die, laser quenching process is usually used to form a certain hardened layer at a specific part of the die. In this paper, the changes of microstructure and hardness of ductile iron GGG70L after laser quenching were studied through a large number of process experiments, and the influence of quenching process parameters on the microstructure and properties of GGG70L was obtained. The relationship between the depth of hardened layer and the laser energy density is established and a quadratic function relationship was found between the two. It is found that both higher hardness and deeper hardening depth can be obtained when the energy density is 24-28 (J/mm2). The finite element model of the laser quenching process of GGG70L was established, and the temperature of the hardened zone and its evolution law during the laser quenching process were studied numerically.

Optimization and analysis of process parameters of melt quenching technique for multiple performances of rare earth doped barium borate glass synthesis using Taguchi's design and grey relational approach

Glass materials with strong physical, structural, and optical properties are in high demand in today's social and industrial sectors. Researchers have recently established the extensive uses of these widely utilized glassy materials in optoelectronic devices, aerospace, nuclear industries, etc. Optimization usually plays a significant role in the synthesis of material. Hence, this article uses the statistical optimization of multiple process parameters of the melt quenching technique for rare earth doped barium borate glass 60B2O3-(40-X)BaO-XMO (MO-Er2O3/CeO2 and X = 0.5,1.0,1.5 mol percentage)by Taguchi's Design of Experiment. The multiple performance characteristics were studied using Grey relational analysis. An experimental format for preparing the Barium Borate glass was utilized with a standard L9 orthogonal array designed by Taguchi. Grey relational analysis was used to analyze the effects of processing parameters, including melting temperature, the composition of rare-earth oxide, and melting time of glasses on density, refractive index, and indirect bandgap. Analysis of variance (ANOVA) showed the influence of process parameters on the multiple response parameters as directed by the S/N ratio of the response parameter. The prediction of optimal conditions for contributing process parameters to the multiple response parameters was estimated efficiently. Additionally, as compared to the initial conditions, the optimal confirmatory experiment exhibited a considerable improvement in the response parameters (refractive index, density, and indirect bandgap). Grey relational grade and analysis of variance (ANOVA) revealed that melting temperature to be sole factor significantly affecting multiple responses with a 95% confidence level. The objective of the work is to optimize the melt quenching process parameters and their influence on the physical and optical properties of glass for photonic applications. Using this optimization method, melt quenching was found to be the most influential parameter contributing about 73–74% in tuning the desired response parameters. The findings also revealed a very less deviation between the statistically predicted and experimental data of response parameter, with deviation ranging from 0.37 to 2.14%. This good agreement between experimental and predicted values of response parameters indicated the suitability of Taguchi method of optimization for melt quenching technique.

Study on the mechanism of carbide precipitation by surface quenching treatment on GCr15 bearing rings based on the phase-field method

In this paper, the thermodynamics database describing Gibbs free energy of FCC phase and M23C6 phase based on Fe-Cr-C ternary alloy was coupled into phase field simulation, and the phase field model was developed on the mesoscopic scale which simulates precipitation, growth and coarsening of M23C6 carbides in FCC austenitic matrix by considering the elastic energy. As the boundary condition of imported phase field calculation, the heat treatment COSMAP software was applied to obtain the macro numerical simulation results of quenching. The phase composition, element distribution, and the evolution including the nucleation, growth and coarsening was simulated by phase field method for the M23C6 carbides in quenching process of GCr15 bearing ring. By means of comparison between the calculation results of phase field simulation and the morphology, quantity and distribution of carbides observed by SEM experiment, this paper present the mechanism on precipitation of micro M23C6 carbides influenced by quenching process parameters, and the experiment verifies the feasibility and accuracy of phase field simulation.

Stress sensitivity analysis of laser quenching based on regression model

In the laser quenching process, quantitative evaluation of the influence of different process parameters on quenching stress is the key to achieve quenching process optimization. A variety of different process parameters are selected as research objects, and a parameterized thermomechanical coupling model of the disk laser hardening process for 45 steel is established. Through the calculation of the model, the instantaneous change law of stress field and the phase change field under different process parameters are obtained, and the response surface equation between the multiphysics solution results and process parameters is established. The Monte Carlo method is used to randomly sample the response equation repeated times, and the sensitivity of quenching process parameters is calculated through sampling results. The calculation result shows that hollow teardroplike stress distribution is formed in the center of the spot during quenching, and the stress around the spot is larger. Thermal stress concentration appears in the reverse direction of quenching scanning, with a maximum value of 850 MPa, and a cometlike stress zone appears in the reverse direction of quenching scanning. The diameter of the laser spot is negatively correlated with quenching stress and has the greatest influence on it. The laser incidence angle has a great influence on the depth and width of the phase change layer and is positively correlated. This model can reveal the mechanism of multifield coupling changes in the material during quenching and provide technical and theoretical support for the reasonable selection of process parameters.

Effect of Quenching Parameters on Distortion Phenomena in AISI 4340 Steel

During quenching heat treatment, the formation of high residual stress values and the presence of distortion are phenomena which are difficult to control and accurately predict, their effects being extremely important to the components or pieces of complex and robust geometry that are commonly used in the industry. The latter is mainly due to the mixture of the high temperature levels formed between the surface and the cores of the components and the martensitic transformation during quenching. In this research, an experimental and simulated analysis of the process of the quenching heat treatment of AISI 4340 steel, using geometrically complex components, was undertaken with the objective of studying and understanding the effect of quenching process parameters on distortion, stress generation, and mechanical properties. A model that applied the finite elements method (FEM), in which entry data such as thermo-physical and mechanical properties were obtained through experimental techniques that were reported in the literature, made it possible to simulate the cooling process under different conditions, which helped to explain the origins of the distortion in the quenched parts. The results show a close relationship between various quenching parameters such as heat extraction speed, the immersion orientation in the liquid, and the component’s geometry. The data obtained could contribute to accelerating the design process of the heat processing routes for quenching components by taking into consideration both the classic process variables and, due to the increased precision resulting from mathematical modeling, additional factors such as the geometry of real applications.

Effect of laser quenching process on surface hardness and wear performance of cylindrical slideway on the upper base of combined vibration separation equipment

Abstract Combined vibration equipment is widely used in the separation and classification of grain, mineral and other granular materials. The cylindrical slideway on the upper part of the base of the combined vibration equipment bears all the weight of the vibrating silo and the particulate matter in the vibrating silo during the vibration process, and supports the combined vibration of the vibrating silo and the particulate matter in the vibrating silo, the cylindrical slideway on the upper part of the base is seriously worn. The vibrating silo can only vibrate horizontally and linearly along the cylindrical slide on the upper part of the base and swing back and forth around the center of the bottom surface of the cylindrical slide on the upper part of the base. It is required that the cylindrical slide on the upper part of the base has good strength and toughness, and the contact surface has a hardness of more than 35HRC to ensure wear resistance. The effect of laser surface quenching process on the surface hardness of the upper cylindrical slide of the base is studied by using the method of three factors and four levels. The experimental results show that after laser surface quenching, the minimum surface hardness and the maximum surface hardness of the upper cylindrical slide of the base are 35.6HRC and 39.6HRC, which meet the hardness requirements of vibration equipment for the slide of the base. When 1450W laser quenching power, 500mm/min laser scanning speed and 2.25mm laser spot diameter are used, the maximum surface hardness will be 39.6HRC, which is about 38.6% higher than that of the pretreated sample. The maximum section hardness of test sample 14 after laser quenching reaches 388HV, which is about 1.25 times higher than that of the matrix in the quenching areas of samples 13, 15 and 16. It is close to the matrix hardness when it is 1.6mm away from the surface. The thickness of the surface hardened layer exceeds 0.6mm, indicating that the greater the laser power, the greater the thickness of the hardened layer. In the wear test, the minimum wear amount of sample 14 is 0.0331g, which is about 25.2% of the matrix wear amount of 0.1312g. The larger the laser power is, the smaller the scanning speed and spot diameter are, which plays a positive role in promoting the reduction of sample wear. We will use the laser surface quenching process parameters of sample 14: laser power 1450W, spot diameter 2.25mm and scanning speed 500mm/min to conduct laser quenching on the upper cylindrical slide surface of the base of the combined vibration equipment in order to obtain a thicker hardened layer and higher hardness, and greatly improve the service life, safety and stability of the combined vibration equipment.

Constitutive modelling of Usibor® 1500 sheets after intercritical quenching

In this study, 0.9 and 1.8 mm thick Usibor® 1500 sheets were subjected to intercritical quenching by heating to 760-930°C and quenching at a controlled rate. The tensile behavior of as-quenched Usibor® 1500 was experimentally obtained using uniaxial tension tests at strain rates ranging from 0.001 to 0.25 s−1. The constants in the hardening models, including Johnson-Cook, were optimized using a Genetic algorithm and linear regression for each condition at each strain rate. Then, these models were numerically modified to account for heat treatment dependency. Uniaxial tensile tests were simulated using the fitted models and compared to experimental flow curves and strain distribution maps to determine the accuracy of the prediction of each model. Optical microscopy was used to determine the volume fraction of each phase using image processing tools and these characteristics were used to explain the behavior of Usibor® 1500 after intercritical quenching. It was found that intercritical quenching process parameters determine the distribution and morphology of each phase and consequently the range of mechanical properties. This model can be used to simulate the deformation of hot-stamped components with tailored properties produced under controlled austenitization.

Experimental study of quenching agents on Al6061–Al2O3 composite: Effects of quenching treatment to microstructure and hardness characteristics

Aluminium based composite or well known as Aluminium Matrix Composites (AMC) can be improved in terms of mechanical properties with heat treatment. The quenching process parameters such as cooling rate, cooling agent and cooling temperature are predicted to affect the mechanical properties of the AMC. This study presents the results of a series of laboratory experiment to observe hardness ability of the Al6061–Al2O3 composites subjected to quenching agent and particle surface treatment. There are 3 variations of quenching agent and 2 types of reinforcement particle treatment. The quenching agent using water, oil, salt solution (brine), and 0% and 10% weight fraction of Al2O3 reinforcement. The hardness testing is conducted to the Rockwell B scale according to regulation of ASTM E−18. Obtained results indicated that the biggest distortion occurred as influences of quenching brine agent on each variation. The hardness of the 10E specimens (with treatment of Electroless Coating) is higher than the 10 N specimens (with treatment of Non-Electroless Coating). Based on this finding, it can be concluded that quenching agent and electroless coating treatment explicitly affected the hardness of Al6061–Al2O3 composites.

A Numerical Model for the Prediction of Microstructure Distribution across the Thickness of Quenched Steel Plates

In this work we apply a numerical inverse analysis procedure based on the ICME framework to ensure a required microstructure and combination of properties in the quenched plate. The microstructure is decided first, and the cooling profile needed to obtain such microstructure is then calculated using the CALPHAD approach. Subsequently, an inverse analysis of the heat transfer problem provides the description of the convection mechanism in quenching that results in the demanded cooling profile. An additional constraint is set on the through-thickness thermal gradient to achieve a homogeneous microstructure. Finally, the resultant microstructure is computed. By means of the proposed model we are able to retrieve the necessary quenching process parameters and to quantify the influence of these parameters on the temperature and microstructure distribution within the plate after the quenching.

Distortion Mechanisms During Carburizing and Quenching in a Transmission Shaft

Distortion control during industrial carburizing and quenching operation of precision transmission components is of utmost importance due to their direct impact on performance, such as efficiency, noise and vibrations. The importance of controlling various heat treatment process parameters for mitigating distortion is well accepted, but their specific influence on mechanisms is less understood. In the present work, an integrated finite element-based model is used to simulate gas carburizing and quenching operation on a typical transmission shaft. Investigation is carried out on the effect of raw materials, carburizing and quenching process parameters to predict, analyze and minimize distortion. The effect of phase transformation and generation of thermal strain during heating and cooling stage of heat treatment is investigated, and the mechanisms of bending, diameter and length distortion of a shaft are analyzed. The displacive nature of transformation of bainite at higher temperature with its inherent large shear component of deformation was identified to be responsible for bending distortion in a shaft. Bainitic transformation, martensitic transformation and thermal strains developed during quenching cause volume expansion which leads to diameter expansion and lesser length shrinkage. Finally, bending distortion of a shaft and bore distortion of a gear are contrasted, both in terms of mechanisms and distortion control strategies.

Modeling and Analysis of Deformation for Spiral Bevel Gear in Die Quenching Based on the Hardenability Variation

Spiral bevel gears are widely used to transmit energy between intersecting axes. The strength and fatigue life of the gears are improved by carburizing and quenching. A die quenching process is used to control the deformation of the gear. The deformation is determined by the variations in the hardenability for a certain die quenching process. The relationship between hardenability, phase transformation and deformation needs to be studied to minimize deformation during the adjustment of the die quenching process parameters. In this paper, material properties for 22CrMoH steel are determined by the results of Jominy tests, dilatometry experiments and static mechanical property tests. The material models were built based on testing results under the consideration of hardenability variation. An finite element analysis model was developed to couple the phase transformation and deformation history of the complete carburizing and die quenching process for the spiral bevel gears. The final microstructures in the gear were bainite for low hardenability steel and a mixture of bainite and ferrite for high hardenability steel. The largest buckling deformation at the gear bottom surface is 0.375 mm at the outer circle for the low hardenability gear and 0.091 mm at the inner circle for the high hardenability gear.

Production of Amorphous Alloys by Special Electrometallurgy Methods

ABSTRACTFast-quenched alloys with amorphous and microcrystalline structures were obtained by the cooling drum spinning method during plasma-arc melting process. Thermal load measurements carried out during the melting process and the spinning of the molten material that followed, helped us to modify the existing plasma-arc equipment. Metallographic analyses of the amorphous alloys showed the influence of some quenching process parameters on the creation of their microstructure and revealed the nature of the formation of the crystal structures.

Novel water-air circulation quenching process for AISI 4140 steel

AISI 4140 steel is usually used after quenching and tempering. During the heat treatment process in industry production, there are some problems, such as quenching cracks, related to water-cooling and low hardness due to oil quenching. A water-air circulation quenching process can solve the problems of quenching cracks with water and the high cost quenching with oil, which is flammable, unsafe and not enough to obtain the required hardness. The control of the water-cooling and air-cooling time is a key factor in the process. This paper focuses on the quenching temperature, water-air cycle time and cycle index to prevent cracking for AISI 4140 steel. The optimum heat treatment parameters to achieve a good match of the strength and toughness of AISI 4140 steel were obtained by repeated adjustment of the water-air circulation quenching process parameters. The tensile strength, Charpy impact energy at −10 °C and hardness of the heat treated AISI 4140 steel after quenching and tempering were approximately 1098 MPa, 67.5 J and 316 HB, respectively.

Improvement in Yield Strength of Deformed Steel Bar by Quenching Using Taguchi Method

This paper is on improvement in Yield strength of deformed steel bar by quenching using Design of experiment (DOE) for robust process design. The production of high quality deformed steel bar for concrete reinforcement will reduce the construction cost. It is found that the bar produced having variation in yield strength, this major quality problem is considered for improvement. Yield strength of bar is deviated from standard value specified in IS: 1786-1985. Here the study is focused on the robust parameter design for cooling system, to control the process of quenching to get the desired Yield strength of deformed steel bar. The controlling parameters of cooling system were controlled to improve the Yield strength of bar produced. Taguchi method of Orthogonal Array was used to find the effect of parameter on output quality parameter such as yield strength. DOE by Taguchi approach was used for the improvement in Yield strength. We got satisfactory result of yield strength of deformed steel bar having minimum variation from its mean value. Thus the Yield strength of bar has been improved by controlling the Quenching process parameters at optimum level which was found from factor effect plot using DOE by Taguchi Method. In this paper, the study of hot bar quenching process has been investigated. In order to predict the effect of noise factors and signal on response factor of water quenching process. The controlling parameters such as water pressure, speed of rolling, Cooling rate and Finish rolling temperature of bar were the four independent factors and each of them have three levels were considered for DOE and the response was yield strength. An orthogonal array- L9 had been used for the experiment. Here we used DOE by Taguchi method of orthogonal array to find the effect of parameter on Yield strength. Before conducting the experiment, the quenching setup was made ready with all respect to conduct experiment. The experiments were conducted and experimental data was recorded and analyzed by excel statistical method. The graph of main effect plot of factors was drawn, which was used to find the main effect on response. The parameters were controlled properly to minimize variation in yield strength and obtained the desired quality of bar. Here it is found that water pressure had the largest effect on the yield strength. The water pressure was controlled at different level for many experiments as per L-9 array and yield strength for each experiment was noted. The experimental data analyses were done by Minitab Statistical software. We found the optimum level of parameters setting to get optimum level of Yield strength. For this action plan was designed to control water pressure to a specific level as per the conclusion of this experimentation. Then the action plan had been implemented. The deformed bar were produced and checked for its quality; we found satisfactory quality steel bar having optimum Yield strength. The conclusion has been found that the cooling rate affects on yield strength, but cooling rate is controlled by water pressure which is operated using control valve. Hence water pressure has been controlled in quenching process to get the desired quality with minimum variation from standard value. The bar of 8 mm was produced by controlled rolling and quenching process. Speed of rolling was kept constant and PLC control water pressure valve was used instead of manual control valve for controlling the water pressure. II. Cooling system For the given operation conditions, the temperature and its distribution within the bar entering into the quenching play the crucial role in controlling the mechanical properties of the steel bar such as yield strength. Hence understanding of the cooling system is essential. There are three types of most frequently used cooling system in hot rolling; water jet cooling system, water spray cooling system, and mist cooling systems.(3)It is found that, the yield strength depends on cooling rate. Hence to control cooling rate we made the modification in the present system. The water pressure need to be controlled according the speed of rolling of bar and temperature of bar before entering the quenching system. Fig.1 shows the cooling system having water injector, a cooling tube, and a water stripper. As per size of bar to be produced, the length of cooling pipe is selected and the speed of rolling is controlled accurately.Fig.2, shows water pressure control valve in cooling system, the primary and secondary valves are used to control the water supply, another valve is used to control the air

Study of the Impact of Quenching Process Parameters in High Dimension Rings of Steel AISI 4140

ABSTRACTManufacturing of high dimension steel rings impose several technological challenges. The lack of understanding of the principles and practices of quenching can result in inadequate hardness, excessive distortion or scrapping of costly machined components. This paper presents the results of an analytical study of the parameters of the quenching operation, among them the fluid dynamics of the agitation in the quenching media. Velocity components of the fluid were measured using an anemometer inside the quenching tank. Uniformity of agitation is compared with a Computational Fluid Dynamics (CFD) simulation. The CFD results revealed the impact of quench tank design, configuration and operation of impellers.

Application of Response Surface Methodology to Optimize Quenching Process Parameters of 17Cr2Ni2Mo Steel

With fast development of output, light-weighting and high performance of automobile, 17Cr2Ni2Mo steel, as an important vehicle-used gear steel, has to improve properties to fulfill the development. The performance of 17Cr2Ni2Mo steel is affected by quenching process parameters. In order to investigate the effect of austenitizing temperature and holding time on the quenching hardness and tensile strength, the central composite design (CCD) and response surface method (RSM) are applied to optimize the operating variables viz. austenitizing temperature and holding time. Multi-objective optimization developed for the two responses (quenching hardness and tensile strength) indicates the optimum conditions to be 920.46°C of austenitizing temperature and 0 h of holding time, while the values of quenching hardness, tensile strength are not less than 43.47 HRC and 1616.42 MPa. The gear has advantages with mechanical strength and abrasion resistance energy when 17Cr2Ni2Mo steel is produced using the optimum parameters.