Cold Work Tool Steel Research Articles

Experimental Investigation and NSGA-III Multi-Criteria Optimization of 60CrMoV18-5 Cold-Work Tool Steel Machinability Under Dry CNC Hard Turning Conditions

This work concerns an experimental investigation dealing with the machinability of 60CrMoV18-5 cold-work tool steel under dry CNC hard turning conditions using a CBN cutting insert. A response surface experiment based on the central composite design was set to conduct dry CNC hard-turning experiments with three different levels for cutting conditions, cutting speed Vc (m/min), feed rate f (mm/rev), and depth of cut α (mm) while selecting main cutting force and surface roughness Ra as the two machinability responses. The results were analyzed by applying analysis of variance (ANOVA). The effect of cutting conditions on main cutting force and surface roughness was studied through contour plots. Full quadratic regression models were generated to model the relationships between inputs and outputs. Finally, the NSGA-III algorithm was applied to simultaneously optimize the selected machinability parameters by providing beneficial values for determining cutting conditions. The results have shown that surface roughness is mainly affected by feed rate and cutting speed, whereas main cutting force is affected by depth of cut and feed rate.

Tool life improvement for stamping dies in the coining process

ABSTRACT High temperature and high-speed pressing in minting operations lead to the failure of coin-stamping dies. As a result, new coining tools were required more frequently leading to lower operational productivity and higher production costs. This research has examined the effects of materials and surface coating selections on the tool life of the stamping dies in the coining process. The aim of this research was to explore the possibility of extending the tool life of stamping dies. The three kinds of materials under study were alloy tool steel, cold working tool steel, and hot working tool steel. Additionally, Titanium Nitride (TiN) and Chromium Nitride (CrN) surface coating materials using the Physical Vapour Deposition (PVD) process were investigated. The experiment results revealed that the hot working steel yielded the highest tool life of up to 1,300,000 coins, followed by cold working steel at 900,000 coins, and alloy tool steel at 600,000 coins. The CrN PVD coating provided up to more than 400,000 coins compared to TiN PVD coating on hot working tool steel.

Influence of cryogenic treatment and tempering temperature on microstructural evolution and dry sliding wear behavior of AISI D3 cold-work tool steel

Abstract AISI D3 cold work steel was shallow and deep cryogenically treated and double tempered at 150, 250, and 350 °C temperatures. Cryogenic processes transformed the retained austenite into martensite, while double tempering produced Fe, Cr, and W-rich carbides. The wear losses of cryogenically treated specimens decreased by up to 60% compared to conventionally heat-treated samples. Worn surfaces mainly experienced abrasive and adhesive wear mechanisms. Due to the formation of homogeneously dispersed fine carbides at 250 °C, oxidative wear occurred at the matrix phase, resulting in the lowest wear rate. The samples tempered at 150 °C suffered from the severe abrasive action of hard carbide particles, while the samples treated at 350 °C failed because of carbide coarsening.

Corrosion Resistance and Fracture Toughness of Cryogenic-Treated X153CrMoV12 Tool Steel

Abstract Cryogenic treatment can be employed as an additional heat treatment step for martensitic steels, particularly high-carbon and high-alloy tool steels, to improve their mechanical properties and wear resistance. This enhancement results from a transformation of retained austenite and precipitation of finely distributed secondary carbides. The present study examines the impact of a shallow cryogenic treatment, performed between the quenching and tempering processes, on the corrosion resistance and fracture toughness of cold work tool steel X153CrMoV12. The influence of the shallow cryogenic treatment was evaluated using potentiodynamic polarization test, salt spray tests and three-point bending tests in various hydrogen charging conditions. In addition, the microstructure and phase transformation of the tool steel were investigated using high-resolution scanning electron microscopy, X-ray diffraction and dilatometer tests. The results suggest that the shallow cryogenic treatment followed by a single tempering cycle can slightly enhance the corrosion resistance of the steel. More importantly, the shallow cryogenic treatment positively affects fracture toughness and reduces hydrogen susceptibility. It is discussed how these improvements in the properties of the X153CrMoV12 steel are linked to the microstructural changes induced by the shallow cryogenic treatment.

Enhanced Durability of Wood Cutting Tools through Thermal Cycling.

This study investigates the impact of multi-step austenitization heat treatment on the in-service life of modified AISI A8 cold work tool steel knives used in wood cutting. The knives were subjected to two treatment methods: single quenching and double tempering (SQDT) and double quenching and double tempering (DQDT). Both treatments were followed by physical vapor deposition (PVD) coating to enhance surface properties. The DQDT treatment resulted in a finer microstructure and more uniform carbide distribution. Field tests on 24 knives over 124 h demonstrated up to 130% improvement in wear resistance for DQDT knives, along with superior edge stability and better PVD coating preservation. DQDT knives exhibited ductile fractures characterized by dimples, contrasting with the brittle fracture and cleavage facets in SQDT knives. Residual stress measurements showed higher compressive stresses in DQDT knives (-280 MPa) compared to SQDT knives (-30 MPa), which increased further after field testing. The enhanced performance of DQDT knives is attributed to their refined microstructure, improved carbide distribution, and higher compressive residual stresses, offering significant potential for improving wood cutting tool efficiency and durability.

FeSi-NiAl composite as a future tool material

Composite materials based on NiAl matrix and FeSi reinforcement are tested as potential tool materials in this work. The components (FeSi, NiAl) were prepared by mechanical alloying separately, blended and consolidated by spark plasma sintering method. The results showed that the composite blend can be successfully sintered at 1000 °C. Thermodynamic calculations were performed in SW Thermo-Calc, ver. 2019a for obtaining the phase diagrams of the studied systems. The composite has the hardness almost comparable with the heat-treated cold work tool steels. The hardness increases with the growing amount of silicide in the mixture. The same trend can be slightly visible also in wear resistance and the results nearly reach the performance of high-grade cold-work tool steels but having lower friction coefficient. The ultimate compressive strength reached values of 1830 - 2640MPa, depending on chemical composition. The result indicate that these materials could reach the performance of the high grades of tool steel, but without the need for any heat treatment, which makes them to be a really promising eco-friendly alternative.

Impact of Heat Treatment Conditions and Cold Plastic Deformation on Secondary Hardening and Performance of Cold Work Tool Steel X160CrMoV12

In this study, the effect of the cold plastic deformation of a Bridgman anvil at room temperature on the hardness and wear resistance of X160CrMoV12 steel was investigated by utilizing the hardness test, X-ray diffraction (XRD), abrasive emery wear (AEMW) test, optical examination, and scanning electron microscopy (SEM). Three batches of samples were prepared for the experiment: I—as-hardened, II—after hardening with subsequent tempering at 600 °C for 1.5 h, and III— after hardening with subsequent plastic deformation. The hardening of the samples was performed at three temperatures: 1100 °C, 1150 °C, and 1200 °C. The highest content of retained austenite, as much as 69.02%, was observed during hardening at 1200 °C, while 17.36% and 38.14% were formed at lower temperatures, respectively. After tempering (Batch II), the content of residual austenite decreased proportionally by a factor of about seven for each hardening temperature. The effect of plastic deformation (Batch III) is observed, analyzing the hardness of the samples from the surface to the depth, reaching an average hardened depth of 0.08 mm. To evaluate the wear resistance, the surfaces of the three test batches were subjected to an abrasive emery wear test under a 5 N load. Hardened and plastically deformed samples showed higher wear resistance than hardened and tempered samples. The results confirmed that the optimal hardening temperature to achieve the maximum wear resistance of this steel is 1100 °C.

Comparison of the Properties of Cold Work Tool Steels with the Same Hardness but Different Manufacturing Processes The required important properties

Comparison of the Properties of Cold Work Tool Steels with the Same Hardness but Different Manufacturing Processes The required important properties

A Comparative Study of the As-Built Microstructure of a Cold-Work Tool Steel Produced by Laser and Electron-Beam Powder-Bed Fusion

A Comparative Study of the As-Built Microstructure of a Cold-Work Tool Steel Produced by Laser and Electron-Beam Powder-Bed Fusion

Full Density Powder Metallurgical Cold Work Tool Steel through Nitrogen Sintering and Capsule-Free Hot Isostatic Pressing

Vanadis 4E (V4E) is a powder metallurgical cold work tool steel predominantly used in application with demand for wear resistance, high hardness, and toughness. It is of interest to have a processing route that enables full density starting from clean gas-atomized powder allowing component shaping capabilities. This study presents a process involving freeze granulation of powder to facilitate compaction by means of cold isostatic pressing, followed by sintering to allow for capsule-free hot isostatic pressing (HIP) and subsequent heat treatments of fully densified specimens. The sintering stage has been studied in particular, and it is shown how sintering in pure nitrogen at 1150 °C results in predominantly closed porosity, while sintering at 1200 °C gives near full density. Microstructural investigation shows that vanadium-rich carbonitride (MX) is formed as a result of the nitrogen uptake during sintering, with coarser appearance for the higher temperature. Nearly complete densification, approximately 7.80 ± 0.01 g/cm3, was achieved after sintering at 1200 °C, and after sintering at 1150 °C, followed by capsule-free HIP, hardening, and tempering. Irrespective of processing once the MX is formed, the nitrogen is locked into this phase and the austenite is stabilised, which means any tempering tends to result in a mixture of austenite and tempered martensite, the former being predominate during the sequential tempering, whereas martensite formation during cooling from austenitization temperatures becomes limited.

The role of manufacturing-induced texture on the tribological performance of cold work tool steels

Manufacturing operations produce surface characteristics that, although stochastic, can significantly affect functionality, especially in forming tools, impacting contact and lubrication conditions during operation. This study investigates the influence of stochastic microtextures resulting from milling on the tribological performance of cold work tool steels with two different carbon contents (0.8 and 2 wt%). Different surface textures were observed resulting from the different C contents, with 3D roughness parameters indicating rougher surfaces for the 2.0% wt. C steel. Tribological behavior was assessed using the strip drawing test to analyze friction, wear coefficients, and wear mechanisms. Surface analysis before and after testing was executed employing SEM, EDX, and CLSM, with CLSM also used to determine 3D roughness parameters of the worn tracks. Post-test macrographic analyses and 2D roughness measurements were conducted on the pulled sheets. Tribological test data revealed lower friction and wear coefficients for the 2.0 wt% C tool steel, with susceptibility to abrasion wear, while the 0.8 wt% C tool exhibited a higher tendency towards adhesion wear. Post-test analysis suggested smoother surfaces for the 2.0 wt% C steel compared to the 0.8 wt% C steel. Macrographic analysis showed no visible wear marks on sheets tested with the 2.0 wt% C steel, contrasting with wear grooves visible on sheets pulled against the 0.8 wt% C steel. Additionally, 2D roughness measurements indicated higher roughness after pulling against the 0.8 wt% C tool compared to the 2.0 wt. C tool. Overall, the study demonstrates that manufacturing-induced textures without the need of post-manufacturing texturing influence the tribological performance of the evaluated steels, opening an avenue to be explored to improve the tribological performance of forming tools.

Processability of K340 Cold Work Tool Steel by Directed Energy Deposition Technique

Processability of K340 Cold Work Tool Steel by Directed Energy Deposition Technique

Cutting performance of coated carbide inserts in hard turning of hardened AISI D2 cold work tool steels

Hard turning is a dry machining process that is often preferred over conventional grinding to achieve final dimensions on a workpiece that is already in a hardened state. In this study, hard turning process was preferred due to its numerous advantages such as low machining time, low total production cost, better surface integrity and better environmental effect because of elimination of coolant. The hardness of the material being machined can cause significant wear on the cutting insert. This study investigated the effects of TiCN + Al2O3 + TiN coated carbide inserts on the machining process of hardened AISI D2 cold work tool steel. The temperature of cutting zone, tool wear, flank wear, surface roughness, hardness, chip formation, and microstructure were all measured as a function of cutting speed. A real-time monitoring system was used to measure wear at the tool edge and temperature on the flank face of the cutting insert. The results showed that increasing cutting speed from 100 to 157 m/min led to higher cutting edge temperatures (from 585 to 713°C, respectively) and lower tool flank wear (from 14.6 to 10.8µm, respectively). The multilayer coated carbide inserts produced a ground-quality surface finish with a roughness value of 0.10–0.15 μm. Achieving high cutting edge temperature, low tool flank wear and fine-grinding quality surface finish underscore the effectiveness of using multilayer-coated carbide inserts in the hard turning of hardened steels.

DEUTSCHE EDELSTAHLWERKE CRYODUR 2362

Abstract Deutsche Edelstahlwerke Cryodur 2362 is a high-carbon, chromium-molybdenum-vanadium alloy cold-work tool steel with high tempering resistance. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fatigue. It also includes information on wear resistance as well as forming and heat treating. Filing Code: TS-840. Producer or source: Deutsche Edelstahlwerke Specialty Steel GmbH.

Investigation of Energy Consumption and Surface Roughness in Hot Work Tool Steel (DIN 1.2367) and Cold Work Tool steel (DIN 1.2550)

Investigation of Energy Consumption and Surface Roughness in Hot Work Tool Steel (DIN 1.2367) and Cold Work Tool steel (DIN 1.2550)

Wear characteristics of cold tool steels for recycling plastic preprocessing

Abstract Eight type of commercial cold work tool steels were heat treated to achieve the equal hardness of 650 HV. Heat-treated samples were investigated by optical and scanning electron microscopy (SEM), microhardness, and X-ray diffraction (XRD) to identify microstructural features and phases. The samples were examined in three distinct wear modes: adhesion, two-body wear using pin wear on SiC, and recycling plastic cutting machine, respectively. The wear surfaces of samples were analyzed by 3D scanning technology. The microstructure of steels determined their wear characteristics. For low sliding and higher cutting speeds, the order of adhesive wear performance of the steels was reversed due to the stress occurring in the cutting line. The wear rate of all samples was commensurate with load. In the recycling plastic cutting process, the sample with the minimum and homogeneously dispersed carbides exhibited the best wear performance. Tempering the S3 sample prevented crack formation and improved fracture toughness.

Increasing Energy Efficiency by Optimizing Heat Treatment Parameters for High-Alloyed Tool Steels

AbstractIn the paper industry, machine circular knives are used in the cutting process to provide industrial quality cuts on a variety of products. In the production of paper rolls, they cut the long-rolled paper products into commercial sizes. For this application, the high-alloyed ledeburitic cold work tool steel, DIN EN 1.2379 (X153CrMoV12; AISI D2), in the secondary hardened heat-treated condition has become the widely used industry solution. However, its heat treatment is a very energy-intensive production process. It consists of a quenching from an austenitizing temperature above 1050 °C, followed by three high-temperature tempering steps of more than 500 °C. In the study, the heat treatment process was optimized for energy efficiency, resulting in superior material properties with lower energy consumption. The most promising low energy heat treatment developed in the laboratory was reproduced in the industrial scale, and the required energy consumption was quantified. Subsequently, the resulting properties of the tools such as hardness, wear resistance and fracture toughness were determined. The energy production costs and mechanical properties of the tool steel were evaluated in comparison to conventional production methods. The newly applied heat treatment condition showed very promising and positive results in all analyzed parameters.

Additive manufacturing of carbon-martensitic hardening ledeburitic cold work tool steels using Fused Filament Fabrication and subsequent Supersolidus Liquid-Phase Sintering

Additive manufacturing of carbon-martensitic hardening ledeburitic cold work tool steels using Fused Filament Fabrication and subsequent Supersolidus Liquid-Phase Sintering

A comparison of the performance of cold work tool steels used in die-making

A comparison of the performance of cold work tool steels used in die-making

Comparison of Softening Behavior and Abrasive Wear Resistance between Conventionally and Additively Manufactured Tool Steels

Directed energy deposition (DED) is a powerful method for hard‐facing the existing tool components. Herein, three tool steel grades including a newly developed maraging steel (NMS), a cold work tool steel (V4E), and a high boron steel (HBS) are cladded on a hot work tool steel substrate. After tempering, the cladded tool steels are exposed to high temperatures at 600, 700, and 800 °C for 3 h to evaluate their softening resistance. The results show that all three tool steel grades have a significant hardness drop when the softening temperature reaches 700 °C. The investigated NMS has the lowest initial hardness in the tempered state but the best softening resistance. In contrast, HBS has the highest initial hardness but the worst softening resistance among the three steel grades. V4E tool steel has a moderate softening resistance compared to the other two steel grades. The factors contributing to the softening resistance have been discussed. Corresponding conventional tool steels are also adapted as references for comparison. Except for the NMS, the additive manufacturing tool steel samples have a better softening resistance than the conventional counterparts owing to more alloying elements trapped in the matrix. The abrasive wear resistance of the tempered and softened tool steels manufactured by DED and conventional methods is also evaluated and the wear mechanism is discussed. Besides the hardness, the free spacing λ between coarse hard particles is one of the major factors influencing the abrasive wear resistance.