Cryogenic Heat Treatment Research Articles

Influence of post heat treatment on tribological and microstructural properties of plasma wire arc additive manufactured maraging steels

Abstract Metallic alloys are increasingly being produced using wired arc additive manufacturing (WAAM). In this study, 18Ni300 defect-free maraging steels were produced using the WAAM technique. A traditional solution treatment, direct aging, and cryogenic heat treatment processes were applied to the WAAM produced maraging steels. The influence of conventional and novel cryogenic heat treatments on microstructural, mechanical, and tribological properties were examined. The microstructure of the as-built materials obtained by WAAM thermal cycling has mainly been homogenized through the solution, direct-aging, and cryogenic heat treatments. As a result, homogeneously distributed precipitate phases were obtained and the hardness increased by 30 % with a combination different post heat treatments. The cryogenic heat treatment improved the martensitic transformation and facilitated the formation of various Fe–Ni–Mo–Ti-containing intermetallic precipitates. Similarly, because of the different heat treatments, the wear resistance improved by a factor of 2–5.5 relative to the as-built material. Adding the cryogenic heat treatment to the traditional heat treatment procedure improves wear resistance by a factor of 1.2–2.9.

Effect of post-processing on the microstructure and corrosion rate of laser powder bed fusioned Ti64-ELI grade alloy

In this study, the influence of post-annealing at 800 °C and cryogenic heat treatment at −196 °C of as-print laser powder bed fusioned Ti64-ELI alloy on the microstructure and corrosion behavior is investigated and its performance was compared with that of as-cast Ti64-ELI alloy. The acicular martensitic phase of the as-print sample degraded into alpha and beta phase upon heat treatment. The Tafel curve was obtained after electrochemical corrosion analysis and it was observed that the as-print sample had a higher corrosion rate due to the increased martensitic phase content present in the sample. The degradation of the unstable martensitic(α’) phase and the increased presence of β-phase content after post processing (annealing and cryogenic treatment) significantly improved the corrosion resistance of as-print sample.

Electro discharge machining performance of cryogenic heat treated copper electrode

Abstract In this study, the EDM machining performance of a cryogenic heat treated copper electrode was investigated. Within the scope of the study, electrodes selected from copper material were subjected to cryogenic heat treatment with a cycle between [room temperature/ − 184 °C/room temperature]. In the experimental design, the electrode material was changed at two levels: copper electrode (Cu) and cryogenic copper electrode (CCu). Controllable machine parameters, peak current (Ip), active pulse duration (Ton), pulse gap duration (Toff) and gap voltage (Vg) were changed at three levels. The effects of these parameters on outputs such as recast layer thickness (RLT), material removal rate (MRR), electrode wear rate (EWR) and taper angle (TA), which are taken into consideration in determining the processing quality after EDM machining experiments, were taken into account. A total of 18 experiments were carried out on Ti–6Al–4V (Titanium alloy) workpiece with copper electrode. Lower YKTK with combinations of EDM process parameters such as cryogenic copper electrode (CCu), 4 A peak current (Ip), 110 µs active pulse duration (Ton), 72 µs pulse gap time (Toff) and 6 V gap voltage (Vg), It was observed that EWR and TA and higher MRR were obtained.

Effect of Cryogenic Heat Treatment on Multiple Tempered D-2 Tool Steel

The present day scenario in the manufacturing sector demands high productivity and the life of cutting tools plays a major role in increasing productivity. The freezing of metals has been acknowledged, for many decades, as an effective method for increasing" wear life" and decreasing residual stress in tool steels. Wear test using pin-on-disc machine was used to investigate the effect of multiple tempering after cryogenic treatment of D-2 tool steel. Conventional quenching (1010◦C) and tempering (515◦C) treatments were given along with intermediate cryogenic treatment (−196◦C). Specimens were subjected to wear tests on pin-on-disc machine in dry sliding condition for sliding distance of 6000 m at 6 kg load and for sliding speed of 3.0 m/s. Hardness data, microstructures, wear loss and Microstructure analys is analysis of worn surface throw light on the underlying metallurgical mechanism responsible in improving wear resistance property of the D-2 tool steel

Susceptibility of X17CrNi16-2 martensitic stainless steel to hydrogen embrittlement after conventional and deep cryogenic heat treatment

A low carbon/ high chromium martensitic stainless steel, X17CrNi16-2, was heat treated using two different hardening and tempering regimes (1050 °C/480 °C or 980 °C/600 °C) — promoting either a high strength or high toughness state, respectively − and further combined with deep cryogenic treatment (DCT) at −196 °C for 24 h. Over recent years DCT has been recognized as a promising technique to improve the properties of steel, predominantly with respect to its tensile strength, toughness and wear resistance. The influence of DCT on the hydrogen embrittlement resistance of martensitic stainless steel has not yet, however, been reported.A slow strain rate tensile test (SSRT) with simultaneous cathodic hydrogen charging was selected as the method to assess potential susceptibility to hydrogen embrittlement (HE). Relatively low-intensity hydrogen charging, utilizing a constant current density of 0.1 mA/cm2, in a non-corrosive, slightly alkaline buffer solution, led to a clear reduction in the ultimate tensile stress. This reduction, and therefore the HE susceptibility, was more pronounced in the steel with a higher strength (i.e. that subject to the 1050 °C/ 480 °C heat treatment condition). Furthermore, DCT did not appear to have any impact on the steel’s mechanical properties in the presence of hydrogen. Fractographic analysis showed clear evidence of HE in the hydrogen-charged specimens.This paper presents results of the SSRT tests and further fractography results, and discusses the impact of conventional and deep cryogenic treatment on HE susceptibility.

Mechanism of cryogenic, solid solution and aging compound heat treatment of die-cast Al alloys considering microstructure variation

Mechanism of cryogenic, solid solution and aging compound heat treatment of die-cast Al alloys considering microstructure variation

Effect of Shallow Cryogenıc Heat Treatment on Metal Inert Gas Weldıng Zone of S 355 J2 Steel

Metal inert gas welding (MIG) is generally conducted in the pressure vessel industry due to its high quality and easy automation. S355 J2 steel is used widely in this industry for its proper welding properties. To carry out and obtain high melting efficiency for satisfactory mechanical properties according to welding parameters, sometimes heat treatment is applied to materials, but generally it is not common in welding industry. In this study the effect of conventional heat treatment and shallow cryogenic heat treatment effects to the mechanical properties of welding zone of S 355 J2 steel welded with MIG is investigated. The charpy impact tests have been carried out. The welding plate is prepared according to this purpose and it is cut for impact test samples 10 X 10 x 55 mm. Totally 30 samples are prepared for 5 processes. Process 1: 6 samples for without heat treatment. Process 2: 6 samples for normalization-quenching in water. Process 3: 6 samples for normalization-quenching-tempering. Process:4 6 samples for normalization-shallow cryogenic treatment. Process 5: 6 samples for normalization-shallow cryogenic treatment-tempering. Notch of impact test samples are prepared just in the middle of the welding zone (2 sample for each process) , HAZ (2 sample for each process) and basemetal (2 sample for each process). The hardness values are taken from base metal, heat affected zone and welding area respectively. Hardness values and impact test results are compared. As a result, generally, it has been observed that shallow cryogenic heat treatment have a remarkable effect on toughness, despite a little decrease in hardness. The toughness of welding zone is increased approximately %40 and HAZ % 5 after cryogenic heat treatment. The hardness of WZ is increased approximately % 5 after cryogenic heat treatment, no significant change is observed in HAZ.

Effect mechanism of cryogenic treatment on ferroalloy and nonferrous alloy and their weldments: A review

As a different step from conventional heat treatment, cryogenic treatment played a very important role in improving the microstructure and properties of metals. The effect mechanism of cryogenic treatment on steel and non-ferrous metals and their weldments was reviewed. The influence parameters of cryogenic treatment were discussed, and the influence of cryogenic treatment on microstructure was analyzed, which led to the change of tensile strength, corrosion resistance, fatigue resistance, wear resistance and other properties. In addition, the relationship between cryogenic treatment and heat treatment were also discussed. On this basis, the influence mechanism of cryogenic treatment on metal materials was explained from the three aspects of crystal defect, phase transformation and precipitated phase, and the reasons for these phenomena were more deeply understood after cryogenic treatment. On the basis of cryogenic treatment, the method combining with conventional heat treatment and surface treatment was put forward, which provided a new way for obtaining high performance materials. It could be widely used in metal forming and other fields, and provide a broader vision for material post-processing through the prediction of numerical simulation.

Effect of Cryogenic Heat Treatment and Heat Treatment on the Influence of Mechanical, Energy, and Wear Properties of 316L Stainless Steel by Selective Laser Melting

Effect of Cryogenic Heat Treatment and Heat Treatment on the Influence of Mechanical, Energy, and Wear Properties of 316L Stainless Steel by Selective Laser Melting

Optimization of Cutting Conditions, Parameters, and Cryogenic Heat Treatment for Surface Roughness in Milling of NiTi Shape Memory Alloy

Optimization of Cutting Conditions, Parameters, and Cryogenic Heat Treatment for Surface Roughness in Milling of NiTi Shape Memory Alloy

Effect of novel cryogenic treatment in the corrosion behaviour, microstructure analysis and electrochemical properties of Al 6101 closed-cell foam

ABSTRACT The corrosion behaviour of the closed-cell aluminium foam made of Al 6101 alloy in different heat regimes such as heat treatment (HT), cryogenic treatment (CT) and cryogenic heat treatment (CHT) are investigated in this research work. The Electrochemical Impedance Spectroscopy (EIS) and DC polarisation are the techniques employed in this research work. The microstructure, surface morphology and composition of the treated foam samples are evaluated using a high-resolution Scanning Electron Microscope (SEM) and Energy Dispersive Analysis of X-rays (EDAX). The polarisation and electrochemical impedance measurements of the CT and HT foam samples reveal appealing results in the corrosion resistance when comparing with untreated foam sample. From the SEM images, it is evident that the deep cryogenic treatment changes the morphology of Al 6101 foam and the formation of the Guinier-Preston (GP) zone increases the density of dislocation.

Wear evaluation and microstructure analysis of cryogenically treated AISI 440C bearing steel

In this study, two types of cryogenic treatment [deep cryogenic treatment (−196 °C) and shallow cryogenic treatment (−80 °C)] were used to increase wear resistance in AISI 440C bearing steel. Out focus was to find a way to increase wear resistance via deep microstructural analyses, and also to correlate the microstructure with the wear characteristics of specimens subjected to deep cryogenic treatment, conventional heat treatment, or shallow cryogenic treatment. Microstructural examinations of the specimens were performed using scanning electron microscopy, energy dispersive analysis of X-rays, and X-ray diffraction to study the wear characteristics of AISI 440C bearing steel. The results show that the specimens subjected to deep cryogenic treatment have greater wear resistance than the specimens subjected to shallow cryogenic or conventional heat treatment. The wear mechanisms included the formation and delamination of white layers. The microstructure of the steel was altered by the heat treatment process: the precipitation characteristics of the secondary carbides were modified and the levels of retained austenite were reduced, which correlated with the wear characteristics, and were identified as the potential mechanisms behind the increased wear resistance of the bearing steels due to the deep cryogenic treatment.

Effect of cryogenic heat treatment & ageing on ultra fine grained aluminium–lithium alloy- A review

Cryogenic heat treatment process is well known for enhancing the mechanical properties of alloys having considerably low melting points and less weight. This sub-zero treatment process possesses various beneficial effects on the behaviour and the microstructure of the material treated as well. Cryogenic heat treatment is an in-expensive process in comparison with the other heat treatment process undergone to enhance the core properties of the lightweight alloys. Cryogenic heat treatment hence finds the applications in many industries such as automotive, electronics, aerospace and defence. In the proposed review article, the post effects of the cryogenic heat treatment & Ageing on Aluminium 2099 & Aluminium 8090 alloys were discussed. Even though much detailing is remained to be learnt regarding the postal effects of Aluminium alloys undergoing cryogenic heat treatment. The mechanical properties of ultrafine-grained (UFG) Al-Li alloys with post-aging heat treatment have been investigated.

Effect of cryogenic treatment and heat treatment on mechanical and tribological properties of A356 reinforced with SiC

In the Current work A356 alloy (AMCs) are reinforced with the Silicon Carbide (SiC) particulate through the Stir casting process. Here we compare by varying the physical Structure of the AMCs between As – Cast, Heat Treatment and Cryogenic Treatment through which we can successfully obtained the Mechanical properties like Tensile, Brinell Hardness, Corrosion by Weight loss method, Microstructure and Tribological properties like Wear for automotive and other Engineering applications. The work also explains about the fabrication by Stir casting process and testing of A356 with SiC reinforcement particulate for varying wt% of 0%, 4%, 6% 8% and 10%. From the results obtained AMCs have the best characteristics like high strength to weight ratio and low density, because of its light weight and low cost.

Investigating the effect of deep cryogenic heat treatment on the wear behavior of 100Cr6 alloy steel

Investigating the effect of deep cryogenic heat treatment on the wear behavior of 100Cr6 alloy steel

Cryogenic conditioning of microencapsulated phase change material for thermal energy storage

Microencapsulation is a viable technique to protect and retain the properties of phase change materials (PCMs) that are used in thermal energy storage (TES) applications. In this study, an organic ester as a phase change material was microencapsulated using melamine–formaldehyde as the shell material. This microencapsulated PCM (MPCM) was examined with cyclic cryogenic treatment and combined cyclic cryogenic heat treatment processes. The surface morphology studies showed that the shell surfaces had no distortions or roughness after cryogenic treatment. The cryogenically conditioned microcapsules exhibited diffraction peak intensity shifts and crystal structure changes. The onset of melting for the nonconditioned and conditioned microcapsules were measured to be 8.56–9.56 °C, respectively. Furthermore, after undergoing the cryogenic and heat treatment processes, the PCM microcapsules had appreciable latent heat capacities of 39.8 kJ/kg and 60.7 kJ/kg, respectively. Additionally, the microcapsules were found to have good chemical stability after the cryogenic treatment. In addition, the cryogenically conditioned microcapsules were found to be thermally stable up to 128.9 °C, whereas the nonconditioned microcapsules were stable up to 101.9 °C. Based on the test results, it is obvious that the cryogenically conditioned microcapsules exhibited good thermal properties and are very desirable for cool thermal energy storage applications.

Microstructure and Tribological Properties of Tool Steel AISI O2 After Thorough Cryogenic Heat Treatment

Steel AISI O2 (type 9G2) for a cold-working tool after different quenching, tempering, and cryogenic treatment regimes is studied. It is established that after cryogenic treatment the amount of residual austenite decreases by a factor of 4.3 compared with a quenched condition. The highest hardness 69 HRC is achieved after quenching and cryogenic treatment, and in this case wear resistance is higher by a factor of 2.36 than after quenching and tempering. After cryogenic treatment there is also a reduction in friction coefficient.

The effect of cryogenic treatment on dry sliding wear mechanisms in hard coatings

PurposeThe effect of cryogenic heat treatment on the mechanical properties of different materials has been frequently investigated by researchers in recent years. The purpose of this paper is to investigate wear behaviour of monolayer, multilayer and nanocomposite coatings after cryogenic heat treatment. It is a first in its field in terms of both the heat treatment used and the coatings examined.Design/methodology/approachThe aCN/TiAlN, TiAlN and ncTiAlSiN hard coatings deposited on the AISI D2 steel substrate were subjected to cryogenic heat treatment at −145oC and −196oC for 24 h and then tempered at 200oC for 2 h. Then, the samples were subjected to wear tests of 5, 10 and 15 N three different load values. The wear mechanisms occurring on the wear surfaces were determined by scanning electron microscope supported by EDS.FindingsOxidation, fatigue and delamination wear mechanisms were realized on the surfaces of the samples subjected to dry sliding wear test. The wear resistance of S1 increased with cryogenic heat treatment. According to the wear test results of the untreated samples, it was found that the samples with lower hardness than the others had higher wear resistance. The wear resistance of S1 and S2 samples was increased by cryogenic heat treatment. The best wear resistance in all parameters was obtained by S1. Oxidation in the S1 was found to have a positive effect on wear resistance. According to EDS results after wear of S2, chromium-rich layer was found on the surface of the material. It is understood that cryogenic heat treatment causes carbide precipitation in the inner structure of the substrate material.Originality/valueThe effect of cryogenic heat treatment on the mechanical properties of different materials has been frequently investigated by researchers in recent years. In this study, wear behaviour of monolayer, multilayer and nanocomposite coatings after cryogenic heat treatment was investigated. It is a first in its field in terms of both the heat treatment used and the coatings examined.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0111/

Influence of cryogenic heat-treatment soaking period and temperature on performance of sintered carbide cutting tools in milling of Inconel 718

Cryogenic heat treatment is an innovative heat treatment applied to improve the mechanical properties of sintered carbide cutting tools. In this study, the effect of cryogenic heat treatment used at different temperatures and soaking periods on the mechanical properties of carbide cutting tools was investigated. Cryogenic heat treatment was applied at two different temperatures, −145 °C and − 196 °C, for 24 and 36 h soaking periods. The microstructure of the cryogenic heat-treated cutting tool was investigated as microhardness and grain size. As a result of microstructure analysis, heat treatment soaking period was found to be more effective than heat treatment temperature. Milling tests of the Inconel 718 superalloy were performed under dry conditions using cryogenic heat-treated cutting tools and non-heat treated tools. The effect of heat treatment on cutting tool performance was studied in terms of the amount of tool wear, cutting force, surface roughness values. According to the results obtained, the cryogenic heat treatment applied to the cutting tools has a positive effect on cutting performance. In addition, in the examinations carried out on worn cutting tools, effective wear mechanisms were found to be oxidation, adhesion and abrasion.

Study of α”-Martensitic Transformation in Ti35NbxSn Alloys Subjected to Cryogenic Heat Treatment

TiNbSn alloys have been extensively researched due to several properties they exhibit, including high mechanical strength, low elastic modulus, superelasticity, shape memory effect, biocompatibility. The present study evaluated the cryogenic heat treatment in the Ti35NbxSn alloys (x = 0.0; 2.5; 5.0; 7.5). The alloys were arc melted, cold formed and quenched in both water and liquid nitrogen at-198° C. The Ti35Nb2.5Sn alloy was also aged after exposed to both quenching medium. Microstructure and microhardness analyses were performed. Cryogenic treatment was not enough for transformation of primary β phase into martensitic α” in alloys containing 5 and 7.5% Sn. Cryogenic treatment provided β to α” transformation in alloys containing 0 and 2.5% Sn. The Sn-free alloy was more likely to α" transformation in both quenching medium. The alloys microhardness increased with decrease of both quenching temperature and Sn content. The increase of α" is also related to the increase of the alloy microhardness after aging.