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With the introduction of modern low-weight high-strength materials, tools and dies in hot metal forming are exposed to increasingly demanding contact conditions. This requires use of surface engineering techniques and proper balance between core hardness and fracture toughness. However, it is not very straight forward which combination to use in te...
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The hardness, microstructure and wear behavior of EN 1.2379 cold work tool steel were investigated in different heat treatment condition. In metal forming industry tools can be exposed to very complex and surface demanding conditions, which are the re-sult of different mechanical, thermal, chemical or tribological effects and require well defined p...
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... HT steels are designed to improve hardness, toughness, and wear resistance through controlled heating and cooling, which is ideal for PIM purposes because they can maintain shape and structural integrity [64,65]. Suitable steels for this purpose, namely AISI H11 (DIN 1.2343), AISI H13 (DIN 1.2344), and AISI L6 (DIN 1.2714) [66], will be addressed in this [67] for PIM is especially advantageous as it is a vital material for producing tools and dies. It is classified as air-hardening, high Cr, and premium C-steel and is sturdy and abrasive in wear [68]. ...
... Suitable steels for this purpose, namely AISI H11 (DIN 1.2343), AISI H13 (DIN 1.2344), and AISI L6 (DIN 1.2714) [66], will be addressed in this paper. AISI H11 (DIN 1.2343) in tooling applications [67] for PIM is especially advantageous as it is a vital material for producing tools and dies. It is classified as air-hardening, high Cr, and premium C-steel and is sturdy and abrasive in wear [68]. ...
Injection moulds are crucial to produce plastic and lightweight metal components. One primary associated challenge is that these may suffer from different types of failures, such as wear and/or cracking, due to the extreme temperatures (T), thermal cycles, and pressures involved in the production process. According to the intended geometry and respective needs, mould manufacturing can be performed with conventional or non-conventional processes. This work focuses on three foremost alloys: AMPCO® (CuBe alloy), INVAR-36® (Fe-Ni alloys, Fe-Ni36), and heat-treated (HT) steels. An insight into the manufacturing processes’ limitations of these kinds of materials will be made, and solutions for more effective machining will be presented by reviewing other published works from the last decade. The main objective is to provide a concise and comprehensive review of the most recent investigations of these alloys’ manufacturing processes and present the machinability challenges from other authors, discovering the prospects for future work and contributing to the endeavours of the injection mould industry. This review highlighted the imperative for more extensive research and development in targeted domains.
... The formation of an oxide layer acted as a solid lubricant and protected the surface of nitrided steel. A similar behaviour has been observed by other researchers at this test temperature [30,31]. When the temperature was increased from 400 • C to 600 • C, an increase in the average COF values was observed (Figure 9). ...
Plasma nitriding, a surface treatment technique, is gaining popularity, as it is environment-friendly and offers superior mechanical properties. This research studied the wear and friction performance of AISI H13 die steel after plasma nitriding in a gas mixture of N2:H2 at 20:80, 50:50, and 80:20 (volume ratio) at a fixed time and temperature. This work aimed to analyze the sliding wear performance of the plasma-nitrided tool die steel in hot-forming operations at higher loads. Scanning electron microscopy/electron-dispersive spectroscopy (SEM/EDS) and X-ray diffraction (XRD) techniques were used to study the microstructures of the H13 die steel pins after plasma nitriding. Wear tests were performed on a high-temperature tribometer under uni-directional sliding and dry conditions using a high-temperature tribometer under a 50 N load at various operating temperatures ranging from 25 °C to 600 °C. The results show that the plasma-nitriding process with N2:H2 at 20:80 improved the wear behavior of H13 steel. The friction coefficients and wear volume losses for all the plasma-nitrided specimens were less than those of the untreated die steel.
... CoF values were found lowest when the specimen was nitrided with N 2 :H 2 as 20:80. Barrau et al. (2003); Podgornik et al. (2016); Rad et al. (2011) recorded similar values on their untreated and treated specimens. At 200°C, the specimens nitrided with a lesser percentage of nitrogen showed an increase in average CoF values. ...
Wear, plastic deformation, and mechanical fatigue of dies are the most common failures found during hot forming operations at elevated temperatures. The change in frictional behaviour also happens. The performance of the forming operation is affected. To ensure the quality of the end products and productivity, it has become very important to control the wear and friction of die materials. Surface treatment techniques with superior wear properties and good performance can enhance the life and functionality of dies. Plasma nitriding is the most rapidly developing technique for hot forming dies. It is a cost-effective technique and improves the mechanical properties of the die surfaces. This chapter explains the tribology of hot forming dies, the plasma nitriding technique and the procedures to develop plasma nitriding on the die steels. Thereafter, the tribological behaviour of AISI H11 and AISI H13 plasma nitrided die steels has been reported. Plasma nitriding was found to be most promising and effective in reducing wear and friction at elevated temperatures.
... This behavior was explained as dependent on the precipitation state of the steel belonging to the different coating sequences. [47,48] Plasma-nitrided AISI D2 steel shows a good wear resistance due to the optimal precipitates mainly recognized in c¢-Fe 4 N, this is reported to be very effective to improve the wear properties. [49,50] The HAPC 1+ plasma-nitriding coating is shown to have higher wear resistance due to the huge precipitation of hard Si 3 N 4 silicides. ...
Silicon nitride (Si 3 N 4 ) coating was deposited on AISI D2 tool steel through employing duplex surface treatments—pack siliconizing followed by plasma nitriding. Pack cementation was performed at 650 °C, 800 °C, and 950 °C for 2 and 3 hours by using various mixtures to realize the silicon coating. X-ray diffraction analyses and scanning electron microscopy observations were employed for demonstrating the optimal process conditions leading to high coating adhesion, uniform thickness, and composition. The optimized conditions belonging to siliconizing were employed to produce samples to be further processed via plasma nitriding. This treatment was performed with a gas mixture of 75 pct H 2 -25 pct N 2 , at the temperature of 550 °C for 7 hours. The results showed that different nitride phases such as Si 3 N 4 -β, Si 3 N 4 - γ , Fe 4 N, and Fe 3 N can be recognized as coatings reinforcements. It was demonstrated that the described composite coating procedure allowed to obtain a remarkable increase in hardness (80 pct higher with respect to the substrate) and wear resistance (30 pct decrease of weight loss) of the tool steel.
... Other particular heat treatment processes were employed taking into account a double tempering cycle on a hot work tool steel in order to meet desire properties [12]. Modification of the chemical composition was used as a process to improve the properties of tool steels [18,19]. Meanwhile, the service life of these steels can be affected by the severity of the operating conditions and the aggressiveness of the working environment. ...
This work is a contribution in analyzing structure, tribological behavior and corrosion of AISI L6 hardened tool steel. Structural characterization and tribological behavior of steel were investigated using Optical Microscopy (OM), Scanning electron microscopy (SEM), wear testing by friction on a pin-on-disc Tribometer and corrosion by potentiodynamic polarization. Comparing to the as-received steel, hardening has generated a fine martensitic microstructure causing a 1.5 times hardness increase. Hardening has contributed to improvement of wear resistance as the coefficient of friction has decreased from 0.86 to 0.67μ. An increase in corrosion resistance was observed after hardening treatment.
... The content of alloy elements in the GM120 welding wire was significantly higher than that of the experimental steel by contrasting the Tables 1 and 2. Due to the diffusion of alloying element, the alloy elements content of the WM which was near the FL was lower than that of the other locations of the WM. The relatively low microhardness in the FL was primarily induced by the decrease content of alloying element [17][18][19]. The CG with a large amount of lath bainite had higher microhardness compared to the FG, due to the relatively high dislocation density [20]. ...
The microstructural variations in different sub-regions of the Fe–1.2Mn–0.3Cr–1.4Ni–0.4Mo-C steel welded joint were investigated by means of optical microscope and scanning electron microscope equipped with electron backscattered diffraction. This study focused on the correlation between microstructural characteristics and mechanical properties of the welded joint which was carried out by gas metal arc welding. The microhardness of the fusion line (FL) and fine-grained heat affected zone was inferior to other locations of welded joint due to the diffusion of alloy elements and granular bainite phase transformation, respectively. The tensile strength of the welded joint was about 980 MPa, which reached the required strength of the 1000 MPa grade steel plate for hydropower station. The final fracture was located at the weld metal (WM) because that the crack easily nucleated and propagated in proeutectoid ferrite. The impact toughness at −60 °C of various sampling locations for welded joint was higher than 47 J. The low temperature impact toughness improved gradually as the distance between the V-notch and weld center line increased. The inclusions in the WM and non-uniformity of microstructure and composition near the FL could increase the deterioration on impact toughness at −60 °C.
... Hence, wear resistance is of great concern to those who use hot working die steels. 1,2 For example, Hardell et al. 3 found that operating temperature considerably influences friction and wear behaviour during the tribo-contact between high strength boron steel and tool steel. Many studies [4][5][6][7][8] have shown that the wear behaviour of hot working die steel depends strongly on its heat treatment and the resulting microstructure. ...
... 24 Also, with higher austenitizing temperature, there occurs coarsening of carbides, which causes a drop in steel strength. 2 Figure 11 shows the plastic deformation along the wear track for H13 die steel austenitized at different temperatures, but in the tempered state. It was found that H13 steel austenitized at 1060 C exhibits much more ductility compared to the H13 steel austenitized at 1000 C in tempered state. ...
Austenitizing temperature is of great importance to achieve the desired properties of die steel. It governs the number of carbides dissolved in the austenitic matrix, which later transforms to martensite. This paper intends to find out the impact of austenitizing temperature on the wear behaviour of AISI H13 die steel. Austenitizing of H13 steel is done at different temperatures, i.e., 1000 °C, 1020 °C, 1040 °C, 1060 °C and then tempering is done twice at 560 °C for two hours. H13 die steel when tempered after austenitizing at 1020 °C lath martensite of large size is produced. Whereas, quite smaller lath martensitic structure has been observed in H13 die steel tempered after austenitizing at 1060 °C. Wear test investigation carried out using a pin on disc tribometer for H13 steel pins austenitized at different temperatures against D2 steel disc having 61 HRC. It is observed that the wear volume of H13 die steel exhibits an inverse linear relationship with its austenitizing temperature due to an increase in hardness. It is seen that small protective layer like patches of oxidized debris formed on the worn surface of H13 steel austenitized at 1060 °C. Whereas, no such protective layer formation is found on H13 die steel austenitized at a lower temperature. Post wear test, subsurface cross-section study shows plastic deformation of grains just beneath the worn surface along the direction of wear tracks. H13 die steel austenitized at 1060 °C with larger grains shows plastic deformation of grains up to a greater depth. Whereas, H13 die steel austenitized at 1000 °C with finer grain exhibits plastic deformation up to a lesser depth. An increase in grain boundaries of nearly twice is also found below the worn subsurface up to 80 to 100 µm depth. The present study will help to select the austenitizing temperature for H13 die steel to have better wear resistance.
... The coefficient of friction values recorded for both untreated and treated specimens were similar to the other investigations. 48,49 Rad et al. 10 observed that coefficient of friction of plasma-nitrided specimen when tested under load of 80 N and 1 m/s speed at room temperature was 0.39. Karamis et al. 26 showed the variation of coefficient of friction values under different test loads from 0.15 to 0.22 for plasma-nitrided specimens under dry conditions. ...
In the current investigation, an effort was made to analyze the sliding wear and friction characteristics of the surface engineered hot forming tool steel. A surface treatment technique plasma nitriding was developed onto the surface of the hot forming tool steel namely AISI H13 with a view to reduce the friction coefficients and minimize wear. The treatment was done in various N 2 /H 2 gas mixtures for the fixed time of 24 h and at a fixed temperature of 500 ℃. The phases formed on the plasma-nitrided surface have been identified by the X-ray diffraction technique. The surface morphology of nitrided specimens and the composition of the nitride particles have been analyzed using scanning electron microscopy/energy-dispersive spectroscopy techniques. Thereafter, the untreated and treated steel specimens were chosen to slide against high strength low alloy steel (actual workpiece material) at elevated temperatures. The tests were conducted on high-temperature tribometer under the constant load of 25 N at room temperature, 200 ℃, 400 ℃, and 600 ℃. The results have shown that the average friction coefficients and specific wear rate values decrease from room temperature to 400 ℃ and again increase at 600 ℃.
... Surface wear is an important limiting factor in the service life of dies. Hence, it has been of great concern to the die researchers to study the wear resistance of hot work die steel [1][2][3]. Heat treatment has direct relation with the wear resistance of a hot working die steel. Abouei et al. [4] has found that the friction and wear of the steels are related to the microstructure and the wear mechanism. ...
Hot-working die steel should possess good high temperature strength, tempering resistance, ductility and reasonable cost.
Thus, H13 is widely used for forging, extrusion and die casting. Resistance to surface wear of hot working die steel plays
an important role in imparting good finish to the products. The properties required of hot die steel for a given application
can be obtained by controlling heat treatment parameters which produces major changes in microstructure. This paper
intends to find the impact of austenitizing temperature, tempering temperature and tempering time on the wear behavior of
H13 die steel. After heat treating samples at austenitizing temperature of 1020, 1040 and 1060°C; tempering temperature
540, 560 and 580°C; tempering time 1, 2 and 3 h, experimentation on pin-on-disc tribotester is done to measure the H13
die steel sliding wear and coefficient of friction. Using Box–Behnken design a response surface method model is developed
to find the impact of above heat treatment parameters and the adequacy of model is verified through the analysis of
variance (ANOVA) technique. The optimized heat treatment set predicted by desirability function approach is verified
experimentally and the results are found close to the predicted results.
... Figure 9 shows that the friction coefficients were ∼ 0.70 and ∼0.68 for AISI H11 and AISI H13, respectively, at room temperature. Such values were also observed by other researchers [38,39]. After plasma nitriding, both AISI H11and AISI H13 pin specimen showed lower coefficient of friction values. ...
During hot forging/forming operations, the die surface and near surface region is subjected to severe wear. The failure of dies originates from the surface region. In this research work, plasma nitriding was done on two hot forming tool steels namely AISI H11 and AISI H13. The aim is to develop a hard and wear resistance surface required for hot forming operations. The mechanical and microstructural properties of the developed nitrided layer were critically examined. Thereafter the tribological characteristics of the untreated and plasma-nitrided specimens were studied on high-temperature pin-on-disc tribometer under the constant load of 25 N, sliding speed 0.5 m s⁻¹, sliding distance of 1500 m at different temperatures ranging from room temperature to 600°C. The results showed that the main wear mechanisms is predominantly adhesive at room temperatures and 200°C and a combination of adhesive and abrasive at elevated temperatures (400°C and 600°C).
